基于JavaWeb的博客网站的设计与实现外文翻译
基于java的校园论坛网站的开发与设计外文翻译
附录1The application of AjaxSpend a few minutes using your application you selected(browser except),write it down to what user interaction,and then immediately back.For the sake of brevity,I give an example of electronic form,however,points involved here is general enough for various cases,the text editor.Well,we started.First in the spreadsheet to input some equalities,pay attention to,can interact in several ways:edit data,browsing the data using the keyboard and mouse,also can use the mouse to drag to re organize the data.I do these operations,the program gave me feedback.When moving the mouse,the cursor changes shape;when the mouse stops above,button bright;selected text can change color.When a window or dialog box is selected,and usually isnot the same,etc..These are the so-called"rich"interaction.Of course,there are still some room for improvement,but this is a good start.OK,a spreadsheet is a rich client program?Absolutely not.In a spreadsheet or similar desktop applications,business logic and data model is run in a closed environment.In this environment,they clearly understand each other,and can visit each other,and the environment outside of things,is unknown to them.What is the client?It is a separate process of mutual communication program,which is usually run on the server.In general,the server is always bigger than the client,ability,disposition is better,because the server is usually stored multitudeinformation.The client program enables the end users can view and modify the information,when multiple clients connected to the same server,can shareinformation between them.Shows a simple client/server architecture.In the n layer architecture in the modern,the server often and further the back-end server(such as a database)communication,so called"middleware"layeralso plays a role of client and server.End of our Ajax application in the chain,it is only as the client,therefore,for the convenience of discussion,we can put the whole n system as a labeled as"black box server".Spreadsheet applications I only need to manage its own saved a small amount of data in memory or in the local file system.If the design of well structure,couplingform data and it can be very loose,but I can't pass a network to split or sharethem through network.In this sense,the application of electronic form is not a client.The corresponding Web browser is a typical client,which communicate with the Web server,the request page.The browser has abundant functions,used tomanage user browsing behavior,the common function of the back button,the history list and tabbed browsing multiple documents etc..But when we put the site specific Web pages as an application,these general browsing function actuallyand application is,at best,such as spreadsheets and Windows began the relationship between button or the window list.We consider the application of modern Web.For the sake of simplicity,we chose" earth people know"online bookstore.Open the Amazon site in the browser,because before I visited,it will show me a friendlygreeting,somerecommended bibliography,and my purchase history information.Click on any one of the recommended bibliography,will go to another page(at this time,the page to refresh,within a few seconds I what also don't see).The new page is the information relevant to the book review:other books,second-hand books,offer the same author,and other books I read.In short,appears to be very rich,high degree of associated information in front of me.But for me,interactive way is to click on the hyperlink,and then fill in some forms.Suppose I at the keyboard accidentally fell asleep,wake up second days,if not refresh the page,I don't know"Harry Porter"series of books have been published,nor will my list from one page to another page,if I want to see morethings too,because I cannot change the local content area page size.I seem to be in the criticism of the Amazon interface,but it is not the case,I justtook it as an example.In fact,in the traditional Web development of the shackles,they have done very well.But compared to the spreadsheet,and the interaction model is undoubtedly too limited.Why Web is the application of modern still have so many limitations?The currentsituation has some reasonable technical reasons,we have to consider now.The blueprint for the Internet is all the computer in the world are connected,forming a huge computing resources.If the local data and remote invocationequated,then both the analysis of protein components or crack signals from outer space,users need not consider the physical location of the machines,the rest of the computation only pleasure.But unfortunately,the local call and remote invocation is something totally different.Under the current level of technology,the network communication is still a costly things(that is to say,is usually very slow,but unreliable).In the absence of a network called the situation,method and function of different data and theiroperations are located in the same local memory,to transfer data and return the results obtained are very direct.In a remote call,communication in the network at both ends of the two sides to send and receive data requires a lot of computation at the pared with the data back and forth on the line,these calculations require more time consuming.The transmission of a binary data,to go through many steps of coding and decoding,error checking,failure,packet retransmission split andreorganization,data into 0 and 1 binary signal,through the line(or wireless connection to the other party).In the local,call the function call request is encoded as an object,then the object is serialized as a series of bytes,the application layer protocol(usually HTTP)via the physical transmission medium(such as copper cable,optical fiber or radio)send out.On the remote machine,the application layer protocol decoding,the bytedeserialize the data obtained,to create a copy of the requested object.Then the data model is applied to the object and generates a response object.In order to make the response object is passed to the callback function local,all serialization deserialization operation,and the transport layer will be back again.Finally,the response object is passed to the function call local.This interactive process is very complex,but fortunately,it can be done.Modernprogramming environments such Java and Microsoft framework are built with this ability.However,the execution of remote calls,all these operations will still be in the internal execution.If we were using there mote invocation,performance will be affected.That is to say,a remote call is unlikely to have efficiency and local call.What is worse,the instability of network makes the efficiency loss is unpredictable,it is difficult to.In contrast,a local call to run on the local memory,will undoubtedly have an advantage more at this point.And so on,said remote call half a day,between this and the availability of software?The answer is,a relationship.A successful computer user interface must be able to at least level simulation weexperience in the real world.One of the basic rules of interaction is,when wepush,prick or poke about something,it will immediately response.Response timeas long as a little bit out a little,will make people confused,distracted,to shift thefocus from the task at hand to the user interface.Remote calls across the network,need to perform additional operations in great quantities,they tend to put the system to slow down,the user perceived delay.In desktop applications,only when the usability design is very bad,will appear this kind of makes users feel full of bug,unresponsive to the user interface,but in the application of network,what do not get a large number of such interface.Because the network delay is unpredictable,this kind of interface problems oftencome and go like a shadow,it is difficult to carry out the application responsetest.In other words,the network delay is the result of a common cause of the practical application of the interaction.User interface developers for network delay can only assume the worst.Say simply,is to try to make the user interface and network activities unrelated to.Programmers have already created a truly effective and proven solutions,tosolve this problem.To sell a Guan,let us into the real world.In the morning I will do,a very important is to wake my kids go to school.I can stand on the edge of the bed they toss up,chase them up and dressed,but thismethod is very time consuming,it takes me a lot of precious morning timeI want to wake up the children,have a look out the window,often neglected to feed the cat.After the children would ask me to breakfast.As the server process,the children always get up slowly.If I follow the synchronous interaction pattern,will they all day.However,as long as they mumble"I woke up",I can go to do other things,need to come back when they have a look.In computer terms,I need to do is for every child to establish an asynchronous process in a separate thread.After the start,the children will wake up in their ownthreads,the parent thread unnecessary synchronization wait,they afterwards will inform me(which is often asked me to eat).In the process they wake up,I don't need interaction and they,when they had been up and dressed myself,because I have reason to believe that they will do so soon.For any user interface,which is a long established practice,namely to createasynchronous thread,let it in the background who need to calculate a longtimetask,so that the user can continue to do other things.When starting this thread,it is necessary to block the user operation,but after a short period of time can beaccepted,will relieve congestion.Because of the existence of network delay,using asynchronous mode is a good practice to handle any time-consumingremote call.In fact,the network latency problems and solutions related to long-standing.In the old client/server mode,when the poor design of the client program met thehigh load of the server,the user interface will appear delay intolerable.Even in today's Internet era,when to switch the page,if the browser half the things not to,so this situation might be due to network delay caused by.The existing technical conditions,we have no way to remove the network delay,but at least onestrategy,that is the use of asynchronous processing remote calls,isn't it?Worse,for Web developers to do so there is a problem:HTTP protocol is a"request response"mode of the protocol.That is to say,the client requests a document,the server or a return to this document,or tell the client can not findthe document or allows a client to another place to find,also can tell which the client can use the local cache,and so on.To make a long story short,"request response"mode of the protocol is a one-way communication protocol.The clientinitiates a connection to the server,b ut the server can not initiates a connection to the client.Even when the next client,initiate the communication request,forgetful of the server can't remember this client is who(HTTP is a connectionless).Most Web developers to use modern programming language,for example,Java,PHP ,they are familiar with the user session(user session)concept,this is in fact the application server for a remedy can't maintain a connection state of the HTTP protocol.HTTP for the initial design goal well,using some clever processing,it can adapt to the beginning of the design did not consider theoccasion.But the key features of the asynchronous callback scheme of our clientis,will receive two notice,is a time in the thread creation,the other is a time in the end of the thread.The standard HTTP and the traditional Web application model can not provide these.The traditional Web application like Amazon,is built on the concept of the page.Show the user a document,which includes various links and form,the user canaccess further more documentation.This interaction model can support complex data sets on a large scale(like Amazon and other sites have demonstrated),which provides the user experience is enough to meet the needs of business.In ten years,this interaction model laid a deep imprint in our view of theapplication of Internet business.WYSIWYG interface(WYSIWYG)Web authoring tools,making the site more easily to be understood as a stack of pages.The framework of Web server using the state diagram conversion on the pagemodeling.no introduction,the traditional Web application that has been firmlybound in a page refresh operation,as if the refresh is behoove and inevitable,tried processing scheme for any asynchronous never.Of course,no doubt,the traditional Web application must not nothing is right..After all,Amazon in this interaction model to create a successful commercial applications.But this applies to the way Amazon does not necessarily apply to allpeople.Why do you say that?To understand this,we need to study the usermodel(usage pattern).A general discussion of the bicycle and SUV(SUV)merits meaningless.Because they have their own advantages and disadvantages--comfort,speed,fuel consumption or personal identity.Only discussed in particular use mode,this comparison is only meaningful.For example,is to in the rush hour through the center of the city,or to take the whole family,old and young to go on vacation,or just to find a shelter from the rain.In a similar situation like this,can we have a definite object in view to compare.For the user interface,it is the same with.Software usability expert Alan Cooper has written a lot of good articles aboutusage patterns,he defines two main uses:transient(transient)and exclusive(sovereign).Transient applications may use occasionally every day,butalways as a secondary activity,with a sudden.The contrast is sovereign applications,exclusive continued use of application to deal with the user for several hours a day.Many applications have a natural monopoly or transient properties.For example,a word processing software writing is a sovereign application,possible applications also use several transient,such as file management(file open andembed this function will often close the window),dictionary or spell checking tools(many word processing program is also embedded in these functions),andcolleagues contact email and chat tool.For software developers,text editor,debugger or IDE(integrated development environment)is the exclusive.Sovereign applications often use more frequently.Y ou know,a good userinterface is not visible.The measure of a good scale used frequently,is when theuser interface has obvious pause,it affects the user process.For example,from a directory to another directory file to 2 second pause,I can accept with pleasure;but if the two seconds is the place in my is full of passion for paintingsoftware to create an image,or I'm trying to debug a very difficult to deal with thegeneration of code certainly,this makes me feel very uncomfortable.Amazon is a transient application,eBay,Google and most large public Web applications are transient applications.Since the date of birth,the experts had predicted that the traditional desktop applications under Web impact.Over the past ten years,these have not occurred,why?Based on the Web page programfor transient applications is enough,but it is far from enough for a sovereign application.The starting of modern Web browsers and it's original point(a document from a remote server)has not matter,between them like a Swiss Army knife and neolithic hunting tools,it is a world of difference.A variety of interactive components,scripts and plug-ins,these years could not suppress the crazydevelopment,almost forced once again to create a new browsing experience.toprehistoric times visitbrowser.In 1993,netscape founded before the Marc Andreessen(founder of netscape)are lobbying Tim Berners-Lee(founder of Web,the W3C leader)et al.,cited good into a picture label is HTML.A few years ago,a few pioneers began to treat JavaScript as a serious programming language.But on the whole,more people still use it and those whomockwarning box"monkey tricks and click to win awards"advertising a classtogether.The browser wars brought JavaScript a misunderstood,sick children,Ajax can be viewed as his rehabilitation center.As long as the proper guidance,and thento frame it with appropriate,JavaScript will likely become the Internet model citizen.It can really enhance the practicability of Web application,and without forcing users to install additional software,or forcing users to abandon his beloved browser.To obtain mature tools are widely understood can help usachieve this goal.The back of the book design pattern is one such toolmentioned.The promotion and popularization of a new technology,is not only the technical matters,but also social behavior.Once the technology is mature,the people also need to understand how to use it.This step is often by using it to do our very familiar things start.For example,early bicycle called"Trojan wheel"or"pedalinghorse",on his feet tread the reaction force to move forward.As this technology is gradually accepted by the public,then inventors would invent a new way to use,add the pedal,brake,a chain wheel and tire.Each time the invention creation,made the bike in the shadow of more pale horse,that completely disappeared.The same process also occurs in the field of Web development.The technology behind the Ajax have the ability to Web pages into something new somethingcompletely different.Early uses of Ajax try to make Web pages is beginning to look like a"Trojan wheel"neither fish nor fowl.To comprehend the essence of Ajax,we have to forget about the Web page concept,that is to say,we have tobreak these years of experience.In the months after the Ajax officially named,such things have happened a lot.Ajax的应用花几分钟使用一下你选中的应用(浏览器除外),记下它用到了哪些用户交互,然后马上回来。
JAVA外文文献+翻译
Java and the InternetIf Java is, in fact, yet another computer programming language, you may question why it is so important and why it is being promoted as a revolutionary step in computer programming. The answer isn’t immediately obvious if you’re coming from a traditional programming perspective. Although Java is very useful for solving traditional stand-alone programming problems, it is also important because it will solve programming problems on the World Wide Web.1.Client-side programmingThe Web’s initial server-browser design provided for interactive content, but the interactivity was completely provided by the server. The server produced static pages for the client browser, which would simply interpret and display them. Basic HTML contains simple mechanisms for data gathering: text-entry boxes, check boxes, radio boxes, lists and drop-down lists, as well as a button that can only be programmed to reset the data on the form or “submit” the data on the form back to the server. This submission passes through the Common Gateway Interface (CGI) provided on all Web servers. The text within the submission tells CGI what to do with it. The most common action is to run a program located on the server in a directory that’s typically called “cgi-bin.” (If you watch the address window at the top of your browser when you push a button on a Web page, you can sometimes see “cgi-bin” within all the gobbledygook there.) These programs can be written in most languages. Perl is acommon choice because it is designed for text manipulation and is interpreted, so it can be installed on any server regardless of processor or operating system. Many powerful Web sites today are built strictly on CGI, and you can in fact do nearly anything with it. However, Web sites built on CGI programs can rapidly become overly complicated to maintain, and there is also the problem of response time. The response of a CGI program depends on how much data must be sent, as well as the load on both the server and the Internet. (On top of this, starting a CGI program tends to be slow.) The initial designers of the Web did not foresee how rapidly this bandwidth would be exhausted for the kinds of applications people developed. For example, any sort of dynamic graphing is nearly impossible to perform with consistency because a GIF file must be created and moved from the server to the client for each version of the graph. And you’ve no doubt had direct experience with something as simple as validating the data on an input form. You press the submit button on a page; the data is shipped back to the server; the server starts a CGI program that discovers an error, formats an HTML page informing you of the error, and then sends the page back to you; you must then back up a page and try again. Not only is this slow, it’s inelegant.The solution is client-side programming. Most machines that run Web browsers are powerful engines capable of doing vast work, and with the original static HTML approach they are sitting there, just idly waiting for the server to dish up the next page. Client-side programming means that the Web browser is harnessed to do whatever work it can, and the result for the user is a much speedier and more interactive experience at your Web site.The problem with discussions of client-side programming is that they aren’t very different from discussions of programming in general. The parameters are almost the same, but the platform is different: a Web browser is like a limited operating system. In the end, you must still program, and this accounts for the dizzying array of problems and solutions produced by client-side programming. The rest of this section provides an overview of the issues and approaches in client-side programming.2.Plug-insOne of the most significant steps forward in client-side programming is the development of the plug-in. This is a way for a programmer to add new functionality to the browser by downloading a piece of code that plugs itself into the appropriate spot in the browser. It tells the browser “from now on you can perform this new activity.” (You ne ed to download the plug-in only once.) Some fast and powerful behavior is added to browsers via plug-ins, but writing a plug-in is not a trivial task, and isn’t something you’d want to do as part of the process of building a particular site. The value of the plug-in for client-side programming is that it allows an expert programmer to develop a new language and add that language to a browser without the permission of the browser manufacturer. Thus, plug-ins provide a “back door” that allows the creation of new client-side programming languages (although not all languages are implemented as plug-ins).3.Scripting languagesPlug-ins resulted in an explosion of scripting languages. With a scripting language you embed the source code for your client-side program directly into the HTML page, and the plug-in that interprets that language is automatically activated while the HTML page is being displayed. Scripting languages tend to be reasonably easy to understand and, because they are simply text that is part of an HTML page, they load very quickly as part of the single server hit required to procure that page. The trade-off is that your code is exposed for everyone to see (and steal). Generally, however, you aren’t doing amazingly sophisticated things with scripting languages so this is not too much of a hardship.This points out that the scripting languages used inside Web browsers are really intended to solve specific types of problems, primarily the creation of richer and more interactive graphical user interfaces (GUIs). However, a scripting language might solve 80 percent of the problems encountered in client-side programming. Your problems might very well fit completely withinthat 80 percent, and since scripting languages can allow easier and faster development, you should probably consider a scripting language before looking at a more involved solution such as Java or ActiveX programming.The most commonly discussed browser scripting languages are JavaScript (which has nothing to do with Java; it’s named that way just to grab some of Java’s marketing momentum), VBScript (which looks like Visual Basic), and Tcl/Tk, which comes from the popular cross-platform GUI-building language. There are others out there, and no doubt more in development.JavaScript is probably the most commonly supported. It comes built into both Netscape Navigator and the Microsoft Internet Explorer (IE). In addition, there are probably more JavaScript books available than there are for the other browser languages, and some tools automatically create pages using JavaScript. However, if you’re already fluent in Visual Basic or Tcl/Tk, you’ll be more productive using those scripting languages rather than learning a new one. (You’ll have your hands full dealing with the Web issues already.)4.JavaIf a scripting language can solve 80 percent of the client-side programming problems, what about the other 20 percent—the “really hard stuff?” The most popular solution today is Java. Not only is it a powerful programming language built to be secure, cross-platform, and international, but Java is being continually extended to provide language features and libraries that elegantly handle problems that are difficult in traditional programming languages, such as multithreading, database access, network programming, and distributed computing. Java allows client-side programming via the applet.An applet is a mini-program that will run only under a Web browser. The applet is downloaded automatically as part of a Web page (just as, for example, a graphic is automatically downloaded). When the applet is activated it executes a program. This is part of its beauty—it provides you with a way to automatically distribute the client software from the server at the time the user needs the client software, and no sooner. The user gets the latest version of the client software without fail and without difficult reinstallation. Because of theway Java is designed, the programmer needs to create only a single program, and that program automatically works with all computers that have browsers with built-in Java interpreters. (This safely includes the vast majority of machines.) Since Java is a full-fledged programming language, you can do as much work as possible on the client before and after making requests of the server. F or example, you won’t need to send a request form across the Internet to discover that you’ve gotten a date or some other parameter wrong, and your client computer can quickly do the work of plotting data instead of waiting for the server to make a plot and ship a graphic image back to you. Not only do you get the immediate win of speed and responsiveness, but the general network traffic and load on servers can be reduced, preventing the entire Internet from slowing down.One advantage a Java applet has ove r a scripted program is that it’s in compiled form, so the source code isn’t available to the client. On the other hand, a Java applet can be decompiled without too much trouble, but hiding your code is often not an important issue. Two other factors can be important. As you will see later in this book, a compiled Java applet can comprise many modules and take multiple server “hits” (accesses) to download. (In Java 1.1 and higher this is minimized by Java archives, called JAR files, that allow all the required modules to be packaged together and compressed for a single download.) A scripted program will just be integrated into the Web page as part of its text (and will generally be smaller and reduce server hits). This could be important to the responsiveness of your Web site. Another factor is the all-important learning curve. Regardless of what you’ve heard, Java is not a trivial language to learn. If you’re a Visual Basic programmer, moving to VBScript will be your fastest solution, and since it will probably solve most typical client/server problems you might be hard pressed to justify learning Java. If you’re experienced with a scripting language you will certainly benefit from looking at JavaScript or VBScript before committing to Java, since they might fit your needs handily and you’ll be more productive sooner.to run its applets withi5.ActiveXTo some degree, the competitor to Java is Microsoft’s ActiveX, although it takes a completely different approach. ActiveX was originally a Windows-only solution, although it is now being developed via an independent consortium to become cross-platform. Effectively, ActiveX says “if your program connects to its environment just so, it can be dropped into a Web page and run under a browser that supports ActiveX.” (I E directly supports ActiveX and Netscape does so using a plug-in.) Thus, ActiveX does not constrain you to a particular language. If, for example, you’re already an experienced Windows programmer using a language such as C++, Visual Basic, or Borland’s Del phi, you can create ActiveX components with almost no changes to your programming knowledge. ActiveX also provides a path for the use of legacy code in your Web pages.6.SecurityAutomatically downloading and running programs across the Internet can sound like a virus-builder’s dream. ActiveX especially brings up the thorny issue of security in client-side programming. If you click on a Web site, you might automatically download any number of things along with the HTML page: GIF files, script code, compiled Java code, and ActiveX components. Some of these are benign; GIF files can’t do any harm, and scripting languages are generally limited in what they can do. Java was also designed to run its applets within a “sandbox” of safety, which prevents it from wri ting to disk or accessing memory outside the sandbox.ActiveX is at the opposite end of the spectrum. Programming with ActiveX is like programming Windows—you can do anything you want. So if you click on a page that downloads an ActiveX component, that component might cause damage to the files on your disk. Of course, programs that you load onto your computer that are not restricted to running inside a Web browser can do the same thing. Viruses downloaded from Bulletin-Board Systems (BBSs) have long been a problem, but the speed of the Internet amplifies the difficulty.The solution seems to be “digital signatures,” whereby code is verified to show who the author is. This is based on the idea that a virus works because its creator can be anonymous, so if you remove the anonymity individuals will be forced to be responsible for their actions. This seems like a good plan because it allows programs to be much more functional, and I suspect it will eliminate malicious mischief. If, however, a program has an unintentional destructive bug it will still cause problems.The Java approach is to prevent these problems from occurring, via the sandbox. The Java interpreter that lives on your local Web browser examines the applet for any untoward instructions as the applet is being loaded. In particular, the applet cannot write files to disk or erase files (one of the mainstays of viruses). Applets are generally considered to be safe, and since this is essential for reliable client/server systems, any bugs in the Java language that allow viruses are rapidly repaired. (It’s worth noting that the browser software actually enforces these security restrictions, and some browsers allow you to select different security levels to provide varying degrees of access to your system.) You might be skeptical of this rather draconian restriction against writing files to your local disk. For example, you may want to build a local database or save data for later use offline. The initial vision seemed to be that eventually everyone would get online to do anything important, but that was soon seen to be impractical (although low-cost “Internet appliances” might someday satisfy the needs of a significant segment of users). The solution is the “signed applet” that uses public-key encryption to verify that an applet does indeed come from where it claims it does. A signed applet can still trash your disk, but the theory is that since you can now hold the applet creator accountable they won’t do vicious things. Java provides a framework for digital signatures so that you will eventually be able to allow an applet to step outside the sandbox if necessary. Digital signatures have missed an important issue, which is the speed that people move around on the Internet. If you download a buggy program and it does something untoward, how long will it be before you discover the damage? It could be days or even weeks. By then, how will you track down the program that’s done it? And what good will it do you at that point?7.Internet vs. intranetThe Web is the most general solution to the client/server problem, so it makes sense that you can use the same technology to solve a subset of the problem, in particular the classic client/server problem within a company. With traditional client/server approaches you have the problem of multiple types of client computers, as well as the difficulty of installing new client software, both of which are handily solved with Web browsers and client-side programming. When Web technology is used for an information network that is restricted to a particular company, it is referred to as an intranet. Intranets provide much greater security than the Internet, since you can physically control access to the servers within your company. In terms of training, it seems that once people und erstand the general concept of a browser it’s much easier for them to deal with differences in the way pages and applets look, so the learning curve for new kinds of systems seems to be reduced.The security problem brings us to one of the divisions that seems to be automatically forming in the world of client-side programming. If your program is running on the Internet, you don’t know what platform it will be working under, and you want to be extra careful that you don’t disseminate buggy code. You need something cross-platform and secure, like a scripting language or Java.If you’re running on an intranet, you might have a different set of constraints. It’s not uncommon that your machines could all be Intel/Windows platforms. On an intranet, you’re respon sible for the quality of your own code and can repair bugs when they’re discovered. In addition, you might already have a body of legacy code that you’ve been using in a more traditional client/server approach, whereby you must physically install client programs every time you do an upgrade. The time wasted in installing upgrades is the most compelling reason to move to browsers, because upgrades are invisible and automatic. If you are involved in such an intranet, the most sensible approach to take is the shortest path that allows you to use your existing code base, rather than trying to recode your programs in a new language.When faced with this bewildering array of solutions to the client-side programming problem, the best plan of attack is a cost-benefit analysis. Consider the constraints of your problem and what would be the shortest path to your solution. Since client-side programming is still programming, it’s always a good idea to take the fastest development approach for your particular situation. This is an aggressive stance to prepare for inevitable encounters with the problems of program development.8.Server-side programmingThis whole discussion has ignored the issue of server-side programming. What happens when you make a request of a server? Most of the time the request is simply “send me this file.” Your browser then interprets the file in some appropriate fashion: as an HTML page, a graphic image, a Java applet, a script program, etc. A more complicated request to a server generally involves a database transaction. A common scenario involves a request for a complex database search, which the server then formats into an HTML page and sends to you as the result. (Of course, if the client has more intelligence via Java or a scripting language, the raw data can be sent and formatted at the client end, which will be faster and less load on the server.) Or you might want to register your name in a database when you join a group or place an order, which will involve changes to that database. These database requests must be processed via some code on the server side, which is generally referred to as server-side programming. Traditionally, server-side programming has been performed using Perl and CGI scripts, but more sophisticated systems have been appearing. These include Java-based Web servers that allow you to perform all your server-side programming in Java by writing what are called servlets. Servlets and their offspring, JSPs, are two of the most compelling reasons that companies who develop Web sites are moving to Java, especially because they eliminate the problems of dealing with differently abled browsers.9. separate arena: applicationsMuch of the brouhaha over Java has been over applets. Java is actually a general-purpose programming language that can solve any type of problem—at least in theory. And as pointed out previously, there might be more effective ways to solve most client/server problems. When you move out of the applet arena (and simultaneously release the restrictions, such as the one against writing to disk) you enter the world of general-purpose applications that run standalone, without a Web browser, just like any ordinary program does. Here, Java’s strength is not only in its portability, but also its programmability. As you’l l see throughout this book, Java has many features that allow you to create robust programs in a shorter period than with previous programming languages. Be aware that this is a mixed blessing. You pay for the improvements through slower execution speed (although there is significant work going on in this area—JDK 1.3, in particular, introduces the so-called “hotspot” performance improvements). Like any language, Java has built-in limitations that might make it inappropriate to solve certain types of programming problems. Java is a rapidly evolving language, however, and as each new release comes out it becomes more and more attractive for solving larger sets of problems.Java和因特网既然Java不过另一种类型的程序设计语言,大家可能会奇怪它为什么值得如此重视,为什么还有这么多的人认为它是计算机程序设计的一个里程碑呢?如果您来自一个传统的程序设计背景,那么答案在刚开始的时候并不是很明显。
计算机java外文翻译外文文献英文文献
英文原文:Title: Business Applications of Java. Author: Erbschloe, Michael, Business Applications of Java -- Research Starters Business, 2008DataBase: Research Starters - BusinessBusiness Applications of JavaThis article examines the growing use of Java technology in business applications. The history of Java is briefly reviewed along with the impact of open standards on the growth of the World Wide Web. Key components and concepts of the Java programming language are explained including the Java Virtual Machine. Examples of how Java is being used bye-commerce leaders is provided along with an explanation of how Java is used to develop data warehousing, data mining, and industrial automation applications. The concept of metadata modeling and the use of Extendable Markup Language (XML) are also explained.Keywords Application Programming Interfaces (API's); Enterprise JavaBeans (EJB); Extendable Markup Language (XML); HyperText Markup Language (HTML); HyperText Transfer Protocol (HTTP); Java Authentication and Authorization Service (JAAS); Java Cryptography Architecture (JCA); Java Cryptography Extension (JCE); Java Programming Language; Java Virtual Machine (JVM); Java2 Platform, Enterprise Edition (J2EE); Metadata Business Information Systems > Business Applications of JavaOverviewOpen standards have driven the e-business revolution. Networking protocol standards, such as Transmission Control Protocol/Internet Protocol (TCP/IP), HyperText Transfer Protocol (HTTP), and the HyperText Markup Language (HTML) Web standards have enabled universal communication via the Internet and the World Wide Web. As e-business continues to develop, various computing technologies help to drive its evolution.The Java programming language and platform have emerged as major technologies for performing e-business functions. Java programming standards have enabled portability of applications and the reuse of application components across computing platforms. Sun Microsystems' Java Community Process continues to be a strong base for the growth of the Java infrastructure and language standards. This growth of open standards creates new opportunities for designers and developers of applications and services (Smith, 2001).Creation of Java TechnologyJava technology was created as a computer programming tool in a small, secret effort called "the Green Project" at Sun Microsystems in 1991. The Green Team, fully staffed at 13 people and led by James Gosling, locked themselves away in an anonymous office on Sand Hill Road in Menlo Park, cut off from all regular communications with Sun, and worked around the clock for18 months. Their initial conclusion was that at least one significant trend would be the convergence of digitally controlled consumer devices and computers. A device-independent programming language code-named "Oak" was the result.To demonstrate how this new language could power the future of digital devices, the Green Team developed an interactive, handheld home-entertainment device controller targeted at the digital cable television industry. But the idea was too far ahead of its time, and the digital cable television industry wasn't ready for the leap forward that Java technology offered them. As it turns out, the Internet was ready for Java technology, and just in time for its initial public introduction in 1995, the team was able to announce that the Netscape Navigator Internet browser would incorporate Java technology ("Learn about Java," 2007).Applications of JavaJava uses many familiar programming concepts and constructs and allows portability by providing a common interface through an external Java Virtual Machine (JVM). A virtual machine is a self-contained operating environment, created by a software layer that behaves as if it were a separate computer. Benefits of creating virtual machines include better exploitation of powerful computing resources and isolation of applications to prevent cross-corruption and improve security (Matlis, 2006).The JVM allows computing devices with limited processors or memory to handle more advanced applications by calling up software instructions inside the JVM to perform most of the work. This also reduces the size and complexity of Java applications because many of the core functions and processing instructions were built into the JVM. As a result, software developersno longer need to re-create the same application for every operating system. Java also provides security by instructing the application to interact with the virtual machine, which served as a barrier between applications and the core system, effectively protecting systems from malicious code.Among other things, Java is tailor-made for the growing Internet because it makes it easy to develop new, dynamic applications that could make the most of the Internet's power and capabilities. Java is now an open standard, meaning that no single entity controls its development and the tools for writing programs in the language are available to everyone. The power of open standards like Java is the ability to break down barriers and speed up progress.Today, you can find Java technology in networks and devices that range from the Internet and scientific supercomputers to laptops and cell phones, from Wall Street market simulators to home game players and credit cards. There are over 3 million Java developers and now there are several versions of the code. Most large corporations have in-house Java developers. In addition, the majority of key software vendors use Java in their commercial applications (Lazaridis, 2003).ApplicationsJava on the World Wide WebJava has found a place on some of the most popular websites in the world and the uses of Java continues to grow. Java applications not only provide unique user interfaces, they also help to power the backend of websites. Two e-commerce giants that everybody is probably familiar with (eBay and Amazon) have been Java pioneers on the World Wide Web.eBayFounded in 1995, eBay enables e-commerce on a local, national and international basis with an array of Web sites-including the eBay marketplaces, PayPal, Skype, and -that bring together millions of buyers and sellers every day. You can find it on eBay, even if you didn't know it existed. On a typical day, more than 100 million items are listed on eBay in tens of thousands of categories. Recent listings have included a tunnel boring machine from the Chunnel project, a cup of water that once belonged to Elvis, and the Volkswagen that Pope Benedict XVI owned before he moved up to the Popemobile. More than one hundred million items are available at any given time, from the massive to the miniature, the magical to the mundane, on eBay; the world's largest online marketplace.eBay uses Java almost everywhere. To address some security issues, eBay chose Sun Microsystems' Java System Identity Manager as the platform for revamping its identity management system. The task at hand was to provide identity management for more than 12,000 eBay employees and contractors.Now more than a thousand eBay software developers work daily with Java applications. Java's inherent portability allows eBay to move to new hardware to take advantage of new technology, packaging, or pricing, without having to rewrite Java code ("eBay drives explosive growth," 2007).Amazon (a large seller of books, CDs, and other products) has created a Web Service application that enables users to browse their product catalog and place orders. uses a Java application that searches the Amazon catalog for books whose subject matches a user-selected topic. The application displays ten books that match the chosen topic, and shows the author name, book title, list price, Amazon discount price, and the cover icon. The user may optionally view one review per displayed title and make a buying decision (Stearns & Garishakurthi, 2003).Java in Data Warehousing & MiningAlthough many companies currently benefit from data warehousing to support corporate decision making, new business intelligence approaches continue to emerge that can be powered by Java technology. Applications such as data warehousing, data mining, Enterprise Information Portals (EIP's), and Knowledge Management Systems (which can all comprise a businessintelligence application) are able to provide insight into customer retention, purchasing patterns, and even future buying behavior.These applications can not only tell what has happened but why and what may happen given certain business conditions; allowing for "what if" scenarios to be explored. As a result of this information growth, people at all levels inside the enterprise, as well as suppliers, customers, and others in the value chain, are clamoring for subsets of the vast stores of information such as billing, shipping, and inventory information, to help them make business decisions. While collecting and storing vast amounts of data is one thing, utilizing and deploying that data throughout the organization is another.The technical challenges inherent in integrating disparate data formats, platforms, and applications are significant. However, emerging standards such as the Application Programming Interfaces (API's) that comprise the Java platform, as well as Extendable Markup Language (XML) technologies can facilitate the interchange of data and the development of next generation data warehousing and business intelligence applications. While Java technology has been used extensively for client side access and to presentation layer challenges, it is rapidly emerging as a significant tool for developing scaleable server side programs. The Java2 Platform, Enterprise Edition (J2EE) provides the object, transaction, and security support for building such systems.Metadata IssuesOne of the key issues that business intelligence developers must solve is that of incompatible metadata formats. Metadata can be defined as information about data or simply "data about data." In practice, metadata is what most tools, databases, applications, and other information processes use to define, relate, and manipulate data objects within their own environments. It defines the structure and meaning of data objects managed by an application so that the application knows how to process requests or jobs involving those data objects. Developers can use this schema to create views for users. Also, users can browse the schema to better understand the structure and function of the database tables before launching a query.To address the metadata issue, a group of companies (including Unisys, Oracle, IBM, SAS Institute, Hyperion, Inline Software and Sun) have joined to develop the Java Metadata Interface (JMI) API. The JMI API permits the access and manipulation of metadata in Java with standard metadata services. JMI is based on the Meta Object Facility (MOF) specification from the Object Management Group (OMG). The MOF provides a model and a set of interfaces for the creation, storage, access, and interchange of metadata and metamodels (higher-level abstractions of metadata). Metamodel and metadata interchange is done via XML and uses the XML Metadata Interchange (XMI) specification, also from the OMG. JMI leverages Java technology to create an end-to-end data warehousing and business intelligence solutions framework.Enterprise JavaBeansA key tool provided by J2EE is Enterprise JavaBeans (EJB), an architecture for the development of component-based distributed business applications. Applications written using the EJB architecture are scalable, transactional, secure, and multi-user aware. These applications may be written once and then deployed on any server platform that supports J2EE. The EJB architecture makes it easy for developers to write components, since they do not need to understand or deal with complex, system-level details such as thread management, resource pooling, and transaction and security management. This allows for role-based development where component assemblers, platform providers and application assemblers can focus on their area of responsibility further simplifying application development.EJB's in the Travel IndustryA case study from the travel industry helps to illustrate how such applications could function. A travel company amasses a great deal of information about its operations in various applications distributed throughout multiple departments. Flight, hotel, and automobile reservation information is located in a database being accessed by travel agents worldwide. Another application contains information that must be updated with credit and billing historyfrom a financial services company. Data is periodically extracted from the travel reservation system databases to spreadsheets for use in future sales and marketing analysis.Utilizing J2EE, the company could consolidate application development within an EJB container, which can run on a variety of hardware and software platforms allowing existing databases and applications to coexist with newly developed ones. EJBs can be developed to model various data sets important to the travel reservation business including information about customer, hotel, car rental agency, and other attributes.Data Storage & AccessData stored in existing applications can be accessed with specialized connectors. Integration and interoperability of these data sources is further enabled by the metadata repository that contains metamodels of the data contained in the sources, which then can be accessed and interchanged uniformly via the JMI API. These metamodels capture the essential structure and semantics of business components, allowing them to be accessed and queried via the JMI API or to be interchanged via XML. Through all of these processes, the J2EE infrastructure ensures the security and integrity of the data through transaction management and propagation and the underlying security architecture.To consolidate historical information for analysis of sales and marketing trends, a data warehouse is often the best solution. In this example, data can be extracted from the operational systems with a variety of Extract, Transform and Load tools (ETL). The metamodels allow EJBsdesigned for filtering, transformation, and consolidation of data to operate uniformly on datafrom diverse data sources as the bean is able to query the metamodel to identify and extract the pertinent fields. Queries and reports can be run against the data warehouse that contains information from numerous sources in a consistent, enterprise-wide fashion through the use of the JMI API (Mosher & Oh, 2007).Java in Industrial SettingsMany people know Java only as a tool on the World Wide Web that enables sites to perform some of their fancier functions such as interactivity and animation. However, the actual uses for Java are much more widespread. Since Java is an object-oriented language like C++, the time needed for application development is minimal. Java also encourages good software engineering practices with clear separation of interfaces and implementations as well as easy exception handling.In addition, Java's automatic memory management and lack of pointers remove some leading causes of programming errors. Most importantly, application developers do not need to create different versions of the software for different platforms. The advantages available through Java have even found their way into hardware. The emerging new Java devices are streamlined systems that exploit network servers for much of their processing power, storage, content, and administration.Benefits of JavaThe benefits of Java translate across many industries, and some are specific to the control and automation environment. For example, many plant-floor applications use relatively simple equipment; upgrading to PCs would be expensive and undesirable. Java's ability to run on any platform enables the organization to make use of the existing equipment while enhancing the application.IntegrationWith few exceptions, applications running on the factory floor were never intended to exchange information with systems in the executive office, but managers have recently discovered the need for that type of information. Before Java, that often meant bringing together data from systems written on different platforms in different languages at different times. Integration was usually done on a piecemeal basis, resulting in a system that, once it worked, was unique to the two applications it was tying together. Additional integration required developing a brand new system from scratch, raising the cost of integration.Java makes system integration relatively easy. Foxboro Controls Inc., for example, used Java to make its dynamic-performance-monitor software package Internet-ready. This software provides senior executives with strategic information about a plant's operation. The dynamic performance monitor takes data from instruments throughout the plant and performs variousmathematical and statistical calculations on them, resulting in information (usually financial) that a manager can more readily absorb and use.ScalabilityAnother benefit of Java in the industrial environment is its scalability. In a plant, embedded applications such as automated data collection and machine diagnostics provide critical data regarding production-line readiness or operation efficiency. These data form a critical ingredient for applications that examine the health of a production line or run. Users of these devices can take advantage of the benefits of Java without changing or upgrading hardware. For example, operations and maintenance personnel could carry a handheld, wireless, embedded-Java device anywhere in the plant to monitor production status or problems.Even when internal compatibility is not an issue, companies often face difficulties when suppliers with whom they share information have incompatible systems. This becomes more of a problem as supply-chain management takes on a more critical role which requires manufacturers to interact more with offshore suppliers and clients. The greatest efficiency comes when all systems can communicate with each other and share information seamlessly. Since Java is so ubiquitous, it often solves these problems (Paula, 1997).Dynamic Web Page DevelopmentJava has been used by both large and small organizations for a wide variety of applications beyond consumer oriented websites. Sandia, a multiprogram laboratory of the U.S. Department of Energy's National Nuclear Security Administration, has developed a unique Java application. The lab was tasked with developing an enterprise-wide inventory tracking and equipment maintenance system that provides dynamic Web pages. The developers selected Java Studio Enterprise 7 for the project because of its Application Framework technology and Web Graphical User Interface (GUI) components, which allow the system to be indexed by an expandable catalog. The flexibility, scalability, and portability of Java helped to reduce development timeand costs (Garcia, 2004)IssueJava Security for E-Business ApplicationsTo support the expansion of their computing boundaries, businesses have deployed Web application servers (WAS). A WAS differs from a traditional Web server because it provides a more flexible foundation for dynamic transactions and objects, partly through the exploitation of Java technology. Traditional Web servers remain constrained to servicing standard HTTP requests, returning the contents of static HTML pages and images or the output from executed Common Gateway Interface (CGI ) scripts.An administrator can configure a WAS with policies based on security specifications for Java servlets and manage authentication and authorization with Java Authentication andAuthorization Service (JAAS) modules. An authentication and authorization service can bewritten in Java code or interface to an existing authentication or authorization infrastructure. Fora cryptography-based security infrastructure, the security server may exploit the Java Cryptography Architecture (JCA) and Java Cryptography Extension (JCE). To present the user with a usable interaction with the WAS environment, the Web server can readily employ a formof "single sign-on" to avoid redundant authentication requests. A single sign-on preserves user authentication across multiple HTTP requests so that the user is not prompted many times for authentication data (i.e., user ID and password).Based on the security policies, JAAS can be employed to handle the authentication process with the identity of the Java client. After successful authentication, the WAS securitycollaborator consults with the security server. The WAS environment authentication requirements can be fairly complex. In a given deployment environment, all applications or solutions may not originate from the same vendor. In addition, these applications may be running on different operating systems. Although Java is often the language of choice for portability between platforms, it needs to marry its security features with those of the containing environment.Authentication & AuthorizationAuthentication and authorization are key elements in any secure information handling system. Since the inception of Java technology, much of the authentication and authorization issues have been with respect to downloadable code running in Web browsers. In many ways, this had been the correct set of issues to address, since the client's system needs to be protected from mobile code obtained from arbitrary sites on the Internet. As Java technology moved from a client-centric Web technology to a server-side scripting and integration technology, it required additional authentication and authorization technologies.The kind of proof required for authentication may depend on the security requirements of a particular computing resource or specific enterprise security policies. To provide such flexibility, the JAAS authentication framework is based on the concept of configurable authenticators. This architecture allows system administrators to configure, or plug in, the appropriate authenticatorsto meet the security requirements of the deployed application. The JAAS architecture also allows applications to remain independent from underlying authentication mechanisms. So, as new authenticators become available or as current authentication services are updated, system administrators can easily replace authenticators without having to modify or recompile existing applications.At the end of a successful authentication, a request is associated with a user in the WAS user registry. After a successful authentication, the WAS consults security policies to determine if the user has the required permissions to complete the requested action on the servlet. This policy canbe enforced using the WAS configuration (declarative security) or by the servlet itself (programmatic security), or a combination of both.The WAS environment pulls together many different technologies to service the enterprise. Because of the heterogeneous nature of the client and server entities, Java technology is a good choice for both administrators and developers. However, to service the diverse security needs of these entities and their tasks, many Java security technologies must be used, not only at a primary level between client and server entities, but also at a secondary level, from served objects. By using a synergistic mix of the various Java security technologies, administrators and developers can make not only their Web application servers secure, but their WAS environments secure as well (Koved, 2001).ConclusionOpen standards have driven the e-business revolution. As e-business continues to develop, various computing technologies help to drive its evolution. The Java programming language and platform have emerged as major technologies for performing e-business functions. Java programming standards have enabled portability of applications and the reuse of application components. Java uses many familiar concepts and constructs and allows portability by providing a common interface through an external Java Virtual Machine (JVM). Today, you can find Java technology in networks and devices that range from the Internet and scientific supercomputers to laptops and cell phones, from Wall Street market simulators to home game players and credit cards.Java has found a place on some of the most popular websites in the world. Java applications not only provide unique user interfaces, they also help to power the backend of websites. While Java technology has been used extensively for client side access and in the presentation layer, it is also emerging as a significant tool for developing scaleable server side programs.Since Java is an object-oriented language like C++, the time needed for application development is minimal. Java also encourages good software engineering practices with clear separation of interfaces and implementations as well as easy exception handling. Java's automatic memory management and lack of pointers remove some leading causes of programming errors. The advantages available through Java have also found their way into hardware. The emerging new Java devices are streamlined systems that exploit network servers for much of their processing power, storage, content, and administration.中文翻译:标题:Java的商业应用。
网站建设外文文献翻译
On site construction technology1 IntroductionThe development of network technology for today's global information exchange and sharing funding source in the establishment of contacts and provide more channels and possible. Homes will be known world affairs, according few keyboard or a few mouse clicks can be distant friends thousands of miles away exchanges, and online communications, Internet browsing, on-line interactive, e-commerce has become a modern part of people's lives. Internet era, has created the new people's work and lifestyle, the Internet, openness and sharing of information model, breaking the traditional mode of information dissemination many barriers for people with new opportunities. With computers and the advent of the information age, the pace of the advance of human society in gradually accelerated. In recent years the development of web design, fast people occupied.With the development of web design, a colorful online website together one scenic beauty. To design aesthetic and practical web site should be thoroughly master the building techniques. In building site, we analyzed the websites of objectives, contents, functions, structure, the application of more web design technology. 2 the definition of websit How definition of websitesWeb site identified the tasks and objectives, the building site is the most important issue. Why people will come to your website You have a unique service The first people to your website is to what They will come back All these issues must be taken into account when the site definition of the problem. Definition site to, first of all, the entire site must have a clear understanding of what the design should understand in the end, the main purpose of the mission, how to carry out the task of organization and planning. Second, to maintain the high-quality Web site. Many websites in the face of strong competition from high-quality product is the greatest long-term competitive advantage. An excellent Web site should have the following:1 users visit Web site is faster.2 attention to the feedback and updates. To update the content of the website and timely feedback the user's requirements;3 Home design to be reasonable. Home to the first impression left by visitors is important, the design must be attractive in order to have a good visual effect. The contents of the website and functionThe content of the web site is to be a new, fast, all three sides. The content of the website, including the type of static, dynamic, functional and things to deal with. Website content is determined in accordance with the nature of the site, in the design of the site, commercial websites, popular science site, company websites, teaching and exchange websites, the content and style are different. We have established websites with the nature of these types of sites are not the same. The structure website1 site structure;2 definition of navigation;3 Visual Design;4 framework and design pages. 3 Site Design and ImplementationWith increasing demands on design, high style, high-grade design work before gaining popularity. This also to the designers have put forward higher requirements, from this point of view, the plate design is to meet the requirements of the people should be and Health. The rapid development of science and technology, the Internet into millions of households, also produced a new design space, and a new web design an important part of the field of design. Excellent web design, we must have good creative, so that the audience can be difficult to shift attention long time, produce power. Layout is very important, through text, graphics space portfolio, can best express harmony with the United States. If you want to further understand website design, made separately from other web site's homepage, you need to have more like CSS, javascript, CGI, and other web design technology. In building on the site of the CSS, javascript and other web design technology. Application Design website CSS(1)What is CSS CSS is a style sheet stylesheet technology. Some of them called CSS Cascading Stylesheet.2 the combination of CSS and HTML form. Mode 1: The CSS content, as defined in the writing between the labels. Mode 2: CSS will be preserved as a separate text file, and then from labels to call.3 CSS the web site of examples. The web site pages, and increase the following definition so that the pages show with special effects. Application Design website javascriptjavascript and the emergence of making information between users is not only a display and browse the relationship, but to achieve a real-time,dynamic, cross-expression. Thus based on the CGI static HTML pages will be to provide dynamic real-time information, and customer response to the operation of the Web pages replaced. javascript scripting is satisfy this demand arising from the language. It's loved by extensive user. Many scripting language it is in a relatively good. and effectively achieve the combination of the computer network computing and network blueprint.4 Construction on the site ExperienceWith the popularity of the Internet, more and more government departments, companies and individuals aware of the need to have their own independent Web site. Below on the design and production sites on some of their own experience. After conducting systematic analysis End, we should carry out system design. Web page design similar to the development of software design, top-down, bottom-up and continuous updating, and other design methods. The main task is to design the content of the sites, including the website information organization structure, appearance, content block, navigation and links, directory structure design. System design is the site ready before the concrete realization of the website to further the realization of more specific requirements, the overall effect on the website, local details have a clearer idea. This entire process is the key site planning.Next is how to achieve their own Web site design issues. The realization of the site, I think the need to be considered in two parts: the realization website; Web servers can be achieved. In the process of achieving website, technology selection is very important. Former major use HTML language, the stronger the interactive website, the proposed use of ASP, JSP, PHP and other programming to help achieve,the more complex Web site may also have its own database. The latter is based on all kinds of different operating systems used Web server software installation and debugging. This stage is the whole process of the most important and most time-consuming part.When we completed the work, the need for website released. At this stage of the production on the website drawing to a close, the main task is to do a good job in the website release to the network, the web site for final modifications, testing, homepage can guarantee normal operation of the network.Published in the website after website to deal with various aspects of the tests, including the possibility of any different web browsers, different visitors have shown normal, ASP, JSP, PHP normal procedure can work, and so on. This stage is the website of trial operation period,the website at this time should be to make up for various shortcomings, the website will be more perfected.After a period of operation, the site entered the normal operation period, the main task is to update outdated information website, the visitor's message timely feedback to further improve the website, the introduction of new technologies constantly update website, visit web pages more quickly, more aesthetic appearance, Information Resources richer.Above is the establishment of the station to roughly follow the seven steps, seven steps are complementary, but can be the basis of ease of website and complexity of a weakening or strengthening appropriate link. In short, building a successful web site is not an easy task, it needs all-round consideration, the Composite various factors.5 concluding remarksWith the rapid development of Internet technology, in all walks of life have joined the industry to the Internet. Whether from the management side, or from a commercial point of view, the Internet can bring immense vitality. Internet to become a talented designer Shi new world. People will continue to explore, will be the site of the building in the application of new technologies in the web site.网站建设技术1 介绍网络技术的发展,为今天全球性的信息交流与资源共享和交往提供了更多的途径和可能;足不出户便可以知晓天下大事,按几下键盘或点几下鼠标可以与远在千里之外的朋友交流,网上通信、网上浏览、网上交互、网上电子商务已成为现代人们生活的一部分;Internet 时代, 造就了人们新的工作和生活方式,其互联性、开放性和共享信息的模式,打破了传统信息传播方式的重重壁垒,为人们带来了新的机遇;随着计算机和信息时代的到来,人类社会前进的脚步在逐渐加快;近几年网页设计发展,快得让人目不暇接;随着网页设计技术的发展,丰富多彩的网页成为网上一道亮丽的风景线;要想设计美观实用的网页就应该深入掌握网站建设技术;在建立网站时,我们分析了网站建立的目的、内容、功能、结构,应用了更多的网页设计技术;2 网站的定义如何定义网站确定网站的任务和目标,是建设网站所面临的最重要的问题;为什么人们会来到你的网站你有独特的服务吗人们第一次到你的网站是为了什么他们还会再来吗这些问题都是定义网站时必须考虑的问题;要定义网站,首先,必须对整个网站有一个清晰认识,弄清到底要设计什么、主要的目的与任务、如何对任务进行组织与规划;其次,保持网站的高品质;在众多网站的激烈竞争中,高品质的产品是长期竞争的最大优势;一个优秀的网站应具备:1用户访问网站的速度要快;2注意反馈与更新;及时更新网站内容、及时反馈用户的要求; 3首页设计要合理;首页给访问者留下的第一印象很重要,设计务必精美,以求产生良好的视觉效果;网站的内容和功能在网站的内容方面,就是要做到新、快、全三面;网站内容的类型包括静态的、动态的、功能的和事物处理的;确定网站的内容是根据网站的性质决定的,在设计政府网站、商业网站、科普性网站、公司介绍网站、教学交流网站等的内容和风格时各有不同;我们建立的网站同这些类型的网站性质均不相同;网站的结构1网站的结构; 2定义导航; 3可视化设计; 4设计框架和页面;3 网站的设计与实现随着人们对设计的要求越来越高,高格调,高品位的设计作品,才深受人们的欢迎;这也就给设计者们提出了更高的要求,从这个角度说,板式设计正是满足了人们的要求应需而生;科技的飞跃发展, 让Internet 走进了千家万户,也产生出新的设计领域空间,而网页设计成为新的设计领域的重要内容;优秀的网页设计,必须有好的创意,才能使观者视线久久难移,产生震撼力;版面设计是很重要的,通过文字、图形的空间组合,能最佳的表达出和谐与美;如果想进一步认识网页设计,做出有别于一般网站的网页,就需要掌握更多像CSS 、javascript 、CGI 等网页设计技术;在网站的建设中就应用了CSS 、Javascript 等网页设计技术;应用CSS 设计网页1 什么是CSS CSS 是一种样式表stylesheet技术;也有的人称之为层叠样式表 Cascading Stylesheet;2 CSS与HTML的结合方式;方式一:将所定义的CSS内容书写在这一对标签之间;方式二:将CSS内容单独保存为一个文本文件,再由标签来调用;3 CSS在网站中的应用事例;在网站中的页面,增加了以下的定义, 使页面有特殊的显示效果;应用Javascript 设计网页Javascript的出现使得信息和用户之间不仅只是一种显示和浏览的关系,而是实现了一种实时的、动态的、可交式的表达能力;从而基于CGI静态的HTML 页面将被可提供动态实时信息,并对客户操作进行反应的Web页面的取代;Javascript脚本正是满足这种需求而产生的语言;它深受广泛用户的喜爱;它是众多脚本语言中较为优秀的一种;与的结合有效地实现了网络计算和网络计算机的蓝图;4 关于网站建设的几点体会随着Internet的普及,越来越多的政府部门、公司和个人意识到需要拥有自己的独立网站;下面就设计和制作网站谈谈自己的一些体会;在进行完系统分析之后,我们就应该进行系统的设计;网页的设计类似于软件开发的设计,有自顶向下、自底向上和不断增补等设计方法;主要任务是网页内容的设计,包括网页的信息组织结构、外观、内容分块、导航与链接、目录结构等设计;系统设计是网站具体实现前的准备,对网页的实现进一步提出更具体的要求,对网页的整体效果、局部细节有更明确的设想;这个过程是整个网站规划中的关键;接下来就是如何将自己设计的网站实现的问题;对于网站的实现,我认为需要考虑两部分:网页的实现;Web服务器的实现;在网站实现的过程中,技术选型很重要;前者主要使用HTML语言,对于交互性较强的网站来说,建议采用ASP、JSP、PHP等编程来辅助实现,更为复杂的网站可能还会有自己的数据库;后者则用到各种基于不同操作系统的Web服务器软件的安装、调试;这个阶段是整个过程中最主要也最耗时的一部分;当我们完成了上述工作后,就需要进行网页发布了;到了这个阶段,网页制作就接近尾声,主要工作是把做好的网页发布到网络上,对网页作最后的修改、测试,保证网页能在网络上正常地运行;在网页发布以后,应对网页进行各个方面各种情况的测试,包括网页能否对任何不同的浏览器、不同的访问者都表现正常,ASP、JSP、PHP程序能否正常工作等等;这个阶段是网页的试运行期,此时应把网页的各种缺陷尽量弥补,使网页更加完善;经过一段时期的运行,网站就进入了正常运行期,主要工作是及时更新网页过时的信息,及时对访问者的留言做出反馈,进一步完善网页,不断采用新的技术更新升级网页,使网页的访问更迅速,外观更美观,信息资源更丰富;以上就是建站要大体遵循的七个步骤,这七个步骤是相辅相成的,但可根据网页的难易程度和复杂度适当增强或减弱某个环节;总之,建设一个成功的网站并非一件容易的事,它需要全方位考虑,综合各方面的因素;5 结束语随着Internet技术的突飞猛进,各行各业都在加入Internet的行业中来;无论从管理方面,还是从商业角度来看,Internet都可以带来无限生机;Internet成为了一个设计人员施才华的新天地;人们将不断探索,将网站建设中的新技术应用在网站中;。
计算机专业毕业论文外文翻译
附录(英文翻译)Rich Client Tutorial Part 1The Rich Client Platform (RCP) is an exciting new way to build Java applications that can compete with native applications on any platform. This tutorial is designed to get you started building RCP applications quickly. It has been updated for Eclipse 3.1.2By Ed Burnette, SASJuly 28, 2004Updated for 3.1.2: February 6, 2006IntroductionTry this experiment: Show Eclipse to some friends or co-workers who haven't seen it before and ask them to guess what language it is written in. Chances are, they'll guess VB, C++, or C#, because those languages are used most often for high quality client side applications. Then watch the look on their faces when you tell them it was created in Java, especially if they are Java programmers.Because of its unique open source license, you can use the technologies that went into Eclipse to create your own commercial quality programs. Before version 3.0, this was possible but difficult, especially when you wanted to heavily customize the menus, layouts, and other user interface elements. That was because the "IDE-ness" of Eclipse was hard-wired into it. Version 3.0 introduced the Rich Client Platform (RCP), which is basically a refactoring of the fundamental parts of Eclipse's UI, allowing it to be used for non-IDE applications. Version 3.1 updated RCP with new capabilities, and, most importantly, new tooling support to make it easier to create than before.If you want to cut to the chase and look at the code for this part you can find it in the accompanying zip file. Otherwise, let's take a look at how to construct an RCP application.Getting startedRCP applications are based on the familiar Eclipse plug-in architecture, (if it's not familiar to you, see the references section). Therefore, you'll need to create a plug-in to be your main program. Eclipse's Plug-in Development Environment (PDE) provides a number of wizards and editors that take some of the drudgery out of the process. PDE is included with the Eclipse SDK download so that is the package you should be using. Here are the steps you should follow to get started.First, bring up Eclipse and select File > New > Project, then expand Plug-in Development and double-click Plug-in Project to bring up the Plug-in Project wizard. On the subsequent pages, enter a Project name such as org.eclipse.ui.tutorials.rcp.part1, indicate you want a Java project, select the version of Eclipse you're targeting (at least 3.1), and enable the option to Create an OSGi bundle manifest. Then click Next >.Beginning in Eclipse 3.1 you will get best results by using the OSGi bundle manifest. In contrast to previous versions, this is now the default.In the next page of the Wizard you can change the Plug-in ID and other parameters. Of particular importance is the question, "Would you like to create a rich client application?". Select Yes. The generated plug-in class is optional but for this example just leave all the other options at their default values. Click Next > to continue.If you get a dialog asking if Eclipse can switch to the Plug-in Development Perspective click Remember my decision and select Yes (this is optional).Starting with Eclipse 3.1, several templates have been provided to make creating an RCP application a breeze. We'll use the simplest one available and see how it works. Make sure the option to Create a plug-in using one of the templates is enabled, then select the Hello RCP template. This isRCP's equivalent of "Hello, world". Click Finish to accept all the defaults and generate the project (see Figure 1). Eclipse will open the Plug-in Manifest Editor. The Plug-in Manifest editor puts a friendly face on the various configuration files that control your RCP application.Figure 1. The Hello World RCP project was created by a PDE wizard.Taking it for a spinTrying out RCP applications used to be somewhat tedious. You had to create a custom launch configuration, enter the right application name, and tweak the plug-ins that were included. Thankfully the PDE keeps track of all this now. All you have to do is click on the Launch an Eclipse Application button in the Plug-in Manifest editor's Overview page. You should see a bare-bones Workbench start up (see Figure 2).Figure 2. By using thetemplates you can be up andrunning anRCPapplication inminutes.Making it aproductIn Eclipse terms a product is everything that goes with your application, including all the other plug-ins it depends on, a command to run the application (called the native launcher), and any branding (icons, etc.) that make your application distinctive. Although as we've just seen you can run a RCP application without defining a product, having one makes it a whole lot easier to run the application outside of Eclipse. This is one of the major innovations that Eclipse 3.1 brought to RCP development.Some of the more complicated RCP templates already come with a product defined, but the Hello RCP template does not so we'll have to make one.In order to create a product, the easiest way is to add a product configuration file to the project. Right click on the plug-in project and select New > Product Configuration. Then enter a file name for this new configuration file, such as part1.product. Leave the other options at their default values. Then click Finish. The Product Configuration editor will open. This editor lets you control exactly what makes up your product including all its plug-ins and branding elements.In the Overview page, select the New... button to create a new product extension. Type in or browse to the defining plug-in(org.eclipse.ui.tutorials.rcp.part1). Enter a Product ID such as product, and for the Product Application selectorg.eclipse.ui.tutorials.rcp.part1.application. Click Finish to define the product. Back in the Overview page, type in a new Product Name, for example RCP Tutorial 1.In Eclipse 3.1.0 if you create the product before filling inthe Product Name you may see an error appear in the Problems view. The error will go away when you Synchronize (see below). This is a known bug that is fixed in newer versions. Always use the latest available maintenance release for the version of Eclipse you're targeting!Now select the Configuration tab and click Add.... Select the plug-in you just created (org.eclipse.ui.tutorials.rcp.part1) and then click on Add Required Plug-ins. Then go back to the Overview page and press Ctrl+S or File > Save to save your work.If your application needs to reference plug-ins that cannot be determined until run time (for example the tomcat plug-in), then add them manually in the Configuration tab.At this point you should test out the product to make sure it runs correctly. In the Testing section of the Overview page, click on Synchronize then click on Launch the product. If all goes well, the application should start up just like before.Plug-ins vs. featuresOn the Overview page you may have noticed an option that says the product configuration is based on either plug-ins or features. The simplest kind of configuration is one based on plug-ins, so that's what this tutorial uses. If your product needs automatic update or Java Web Start support, then eventually you should convert it to use features. But take my advice and get it working without them first.Running it outside of EclipseThe whole point of all this is to be able to deploy and run stand-alone applications without the user having to know anything about the Java and Eclipse code being used under the covers. For a real application you may want to provide a self-contained executable generated by an install program like InstallShield or NSIS. That's really beyond the scope of this article though, so we'll do something simpler.The Eclipse plug-in loader expects things to be in a certain layout so we'll need to create a simplified version of the Eclipse install directory. This directory has to contain the native launcher program, config files,and all the plug-ins required by the product. Thankfully, we've given the PDE enough information that it can put all this together for us now.In the Exporting section of the Product Configuration editor, click the link to Use the Eclipse Product export wizard. Set the root directory to something like RcpTutorial1. Then select the option to deploy into a Directory, and enter a directory path to a temporary (scratch) area such as C:\Deploy. Check the option to Include source code if you're building an open source project. Press Finish to build and export the program.The compiler options for source and class compatibility in the Eclipse Product export wizard will override any options you have specified on your project or global preferences. As part of the Export process, the plug-in is code is recompiled by an Ant script using these options.The application is now ready to run outside Eclipse. When you're done you should have a structure that looks like this in your deployment directory:RcpTutorial1| .eclipseproduct| eclipse.exe| startup.jar+--- configuration| config.ini+--- pluginsmands_3.1.0.jarorg.eclipse.core.expressions_3.1.0.jarorg.eclipse.core.runtime_3.1.2.jarorg.eclipse.help_3.1.0.jarorg.eclipse.jface_3.1.1.jarorg.eclipse.osgi_3.1.2.jarorg.eclipse.swt.win32.win32.x86_3.1.2.jarorg.eclipse.swt_3.1.0.jarorg.eclipse.ui.tutorials.rcp.part1_1.0.0.jarorg.eclipse.ui.workbench_3.1.2.jarorg.eclipse.ui_3.1.2.jarNote that all the plug-ins are deployed as jar files. This is the recommended format starting in Eclipse 3.1. Among other things this saves disk space in the deployed application.Previous versions of this tutorial recommended using a batch file or shell script to invoke your RCP program. It turns out this is a bad idea because you will not be able to fully brand your application later on. For example, you won't be able to add a splash screen. Besides, theexport wizard does not support the batch file approach so just stick with the native launcher.Give it a try! Execute the native launcher (eclipse or eclipse.exe by default) outside Eclipse and watch the application come up. The name of the launcher is controlled by branding options in the product configuration.TroubleshootingError: Launching failed because the org.eclipse.osgi plug-in is not included...You can get this error when testing the product if you've forgotten to list the plug-ins that make up the product. In the Product Configuration editor, select the Configuration tab, and add all your plug-ins plus all the ones they require as instructed above.Compatibility and migrationIf you are migrating a plug-in from version 2.1 to version 3.1 there are number of issues covered in the on-line documentation that you need to be aware of. If you're making the smaller step from 3.0 to 3.1, the number of differences is much smaller. See the References section for more information.One word of advice: be careful not to duplicate any information in both plug-in.xml and MANIFEST.MF. Typically this would not occur unless you are converting an older plug-in that did not use MANIFEST.MF into one that does, and even then only if you are editing the files by hand instead of going through the PDE.ConclusionIn part 1 of this tutorial, we looked at what is necessary to create a bare-bones Rich Client application. The next part will delve into the classes created by the wizards such as the WorkbenchAdvisor class. All the sample code for this part may be found in the accompanying zip file.ReferencesRCP Tutorial Part 2RCP Tutorial Part 3Eclipse Rich Client PlatformRCP Browser example (project org.eclipse.ui.examples.rcp.browser)PDE Does Plug-insHow to Internationalize your Eclipse Plug-inNotes on the Eclipse Plug-in ArchitecturePlug-in Migration Guide: Migrating to 3.1 from 3.0Plug-in Migration Guide: Migrating to 3.0 from 2.1译文:Rich Client教程第一部分The Rich Client Platform (RCP)是一种创建Java应用程序的令人兴奋的新方法,可以和任何平台下的自带应用程序进行竞争。
计算机外文翻译---基于PHP和MYSQL的网站设计和实现
译文二:基于PHP和MYSQL的网站设计和实现摘要PHP和MYSQL因为其免费以及开放源码已经成为主要的web开发工具。
作者就基于PHP和MYSQL开发网站进行开发环境问题的讨论。
关键词PHP;MYSQL;发展和实现。
1.介绍随着网络技术的发展,不可避免的带动各种企业传统营销与网络营销的增长。
其中最有效的方法是为他们的公司建立一个网站。
目前网站开发的主流平台包括LAMP(Linux操作系统,Apache网络服务器,MYSQL数据库,PHP编程语言),J2EE 和.NET商业软件。
因为PHP和MYSQL是免费的,开源等等,他们是为专业的IT 人士开发的。
从网站流量的角度来看,超过70%的网站流量是有LAMP提供的,这是最流行的网站开发平台。
在本文中,我们基于PHP和MYSQL设计了一个网站。
本文的组织如下。
第一节分析开发环境。
第二节中,我们提出基于PHP的开发模型。
然后,第四节是案例研究。
在第五节我们做出结论。
2.发展环境分析A.开发语言的选择,PHP&JSP是三个主流的网站开发语言,它们分别具有各自的优点和缺点,它们之间的比较见表1。
这个项目我们采用PHP作为开发语言的原因如下:免费的。
这个项目小,不需要使用支付开发平台如 and JSP。
强大的支持。
中小型网站,甚至一些大型网站如百度,新浪都把PHP作为开发语言,可以有组与解决在编程上的问题。
良好的可移植性。
尽管起初只能在Linux和Apache Web服务器环境中开发,现在已经可以移植到任何的操作系统,并兼容标准的Web服务器软件。
简单的语法。
PHP和C编程语言有许多的相似之处,所以会C的程序员很容易的就能使用PHP程序语言。
发展快速。
因为其源代码是开放的,所以PHP能迅速的发展。
B.构建开发环境目前有很多基于PHP的开发平台。
通常大多数开发人员喜欢LAMP开发环境。
那些有一定开发经验的可以通过选择相关的服务器,数据库管理系统和操作系统设置他们的开发平台。
基于Java的“博客”论坛系统的设计与实现文献综述
基于Java的“博客”论坛系统的设计与实现文献综述文献综述基于Java的“博客”论坛系统的设计与实现一、前言部分“博客”一词源自英文Blog,是其最常用的中文译名。
Blog是Web log(网络日志)的简称,即以Web(网页)的方式显示和发布的日志,一个Blog就是一个网页。
拥有或撰写这些Blog的人称为Blogger或Blog writer,中文称为博主。
博客中每一篇日志或博主写的文章、记录就是一个Post(帖子),中文称之为博文。
博文一般较简洁,而且经常更新,按照时间倒序排列,内容以超链接为表达方式。
对每个博客而言,其链接地址不变,但其包含的内容不断被更新。
1. 新的传播方式。
博客的传播方式是一种多对多的传播,与传统媒体一种一对多的传播方式相反。
正因为如此,它被称为“新媒体”。
《连线》杂志给“新媒体”下的定义很简单:由所有人面向所有人进行的传播(communications for all,by all)。
它使每个人不仅有听的机会,而且有说的条件。
博客从不孤立出现,在浏览博客的时候,你很快会意识到它们构成了网络社区??尤其是那些关系紧密的社区??的基础交流平台[1]。
社区内的人利用博客分享彼此的信息。
网络一向带给人们无障碍沟通的承诺,但博客却真正将此承诺化作了现实[1]。
2. 开放性和共享性。
技术上的突破,使博客具备开放性,进而使人们在信息世界中的角色也发生了巨大改变。
成为博客一族不需要具备某一领域的专业能力,例如计算机编程能力、新闻搜集分析能力、美术设计能力等等,只要有兴趣就足够。
并且从被动的信息接收者,变成信息的首发者、传播者。
另一方面,博客的超级链接功能从而使博客这一新兴媒体完全面向所有人群。
博客作为内容的开放源代码,向外的链接解放了文档,使文档的表现力实现质的飞跃[1]。
正是从这个意义上说,博客比其他网络媒体有更好的优势去实现“个人孤岛”的连接[1]。
3. 个人化和丰富性。
从内容上说,博客区别于其他媒体的另一特征是完全归属于个人,而不由社会组织、企业等团体所拥有。
基于JavaWeb的博客网的设计与实现
图 二 博 客 系统 前 台功 能 结 构 图
Hale Waihona Puke 图四 博 客 系统 用 例 图
r 裔 ; ¨ 1
登 陆
图 三 博 客 系 统后 台功 能 结构 图
2 . 1 . 1 用 户需求 分析
本 系统允许 用户 有三种 身份 :
( 1 ) 博客访问者( 可以浏览信息、 发表评论或留
言) 。
( 2 ) 博客管理员( 注册后登陆, 可以发布 1 3 志、 管
理个 人 主页 ) 。
图五 浏 览模 块 流 程 图
( 3 ) 系统管理员( 对博客管理员的基本信息进行
统一 管理 ) 。
题链 接进 入显 示 日志页 面。二是 点击博 客主题链 接
进 入个 人博客 的首 页 ,然后 在首 页点击 日志标 题链
接 进入 显示 日志页 面 。 三是 通过搜 索功 能 , 搜索 所需 的 日志 ,然后 在结果 列表 中选择 所需 的 日志标 题链
博客 系统用 例 图如 图四所示 。
2 . 1 . 2系统流程
博客系统前 台用户浏览模块流程如图五所示。
前台用户浏览模块主要用于用户浏览 日志信息。它
为 用户 提供 了三种 浏 览方 式 : 一 是直 接 点击 日志标
接 进入 显示 日志页 面 。 浏览 日志 的 同时 , 用户 可 以查 看 别人 对该 日志 的评 论 ,也可 以对该 日志发 表 自己
的评论 。
Java技术介绍-毕业论文外文翻译
Java Technical DescriptionJava as a Programming Platform.Java is certainly a good programming language. There is no doubt that it is one of the better languages available to serious programmers. We think it could potentially have been a great programming language, but it is probably too late for that. Once a language is out in the field, the ugly reality of compatibility with existing code sets in."Java was never just a language. There are lots of programming languages out there, and few of them make much of a splash. Java is a whole platform, with a huge library, containing lots of reusable code, and an execution environment that provides services such as security, portability across operating systems, and automatic garbage collection.As a programmer, you will want a language with a pleasant syntax and comprehensible semantics (i.e., not C++). Java fits the bill, as do dozens of other fine languages. Some languages give you portability, garbage collection, and the like, but they don't have much of a library, forcing you to roll your own if you want fancy graphics or networking or database access. Well, Java has everything—a good language, a high-quality execution environment, and a vast library. That combination is what makes Java an irresistible proposition to so many programmers.Features of Java.1.SimpleWe wanted to build a system that could be programmed easily without a lot of esoteric training and which leveraged today's standard practice. So even though we found that C++ was unsuitable, we designed Java as closely to C++ as possible in order to make the system more comprehensible. Java omits many rarely used, poorly understood, confusing features of C++ that, in our experience, bring more grief than benefit.The syntax for Java is, indeed, a cleaned-up version of the syntax for C++. There is no need for header files, pointer arithmetic (or even a pointer syntax), structures, unions, operator overloading, virtual base classes, and so on. (See the C++ notes interspersed throughout the text for more on the differences between Java and C++.) The designers did not, however, attempt to fix all of the clumsy features of C++. For example, the syntax of the switch statement is unchanged in Java. If you know C++, you will find the transition to the Java syntax easy.If you are used to a visual programming environment (such as Visual Basic), you will not find Java simple. There is much strange syntax (though it does not take long to get the hang of it). More important, you must do a lot more programming in Java. The beauty of Visual Basic is that its visual design environment almost automatically provides a lot of the infrastructure for an application. The equivalent functionality must be programmed manually, usually with a fair bit of code, in Java. There are, however, third-party development environments that provide "drag-and-drop"-style program development.Another aspect of being simple is being small. One of the goals of Java is to enable the construction of software that can run stand-alone in small machines. The size of the basic interpreter and class support is about 40K bytes; adding the basic standard libraries and thread support (essentially a self-contained microkernel) adds an additional 175K.2. Object OrientedSimply stated, object-oriented design is a technique for programming that focuses on the data (= objects) and on the interfaces to that object. To make an analogy with carpentry, an "object-oriented" carpenter would be mostly concerned with the chair he was building, and secondarily with the tools used to make it; a "non-object-oriented" carpenter would think primarily of his tools. The object-oriented facilities of Java are essentially those of C++.Object orientation has proven its worth in the last 30 years, and it is inconceivable that a modern programming language would not use it. Indeed, the object-oriented features of Java are comparable to those of C++. The major differencebetween Java and C++ lies in multiple inheritance, which Java has replaced with the simpler concept of interfaces, and in the Java metaclass model. The reflection mechanism and object serialization feature make it much easier to implement persistent objects and GUI builders that can integrate off-the-shelf components.3. DistributedJava has an extensive library of routines for coping with TCP/IP protocols like HTTP and FTP. Java applications can open and access objects across the Net via URLs with the same ease as when accessing a local file system. We have found the networking capabilities of Java to be both strong and easy to use. Anyone who has tried to do Internet programming using another language will revel in how simple Java makes onerous tasks like opening a socket connection. (We cover networking in Volume 2 of this book.) The remote method invocation mechanism enables communication between distributedobjects (also covered in Volume 2).There is now a separate architecture, the Java 2 Enterprise Edition (J2EE), that supports very large scale distributed applications.4. RobustJava is intended for writing programs that must be reliable in a variety of ways. Java puts a lot of emphasis on early checking for possible problems, later dynamic (run-time) checking, and eliminating situations that are error-prone.… The single biggest difference between Java and C/C++ is that Java has a pointer model that eliminates the possibility of overwriting memory and corrupting data.This feature is also very useful. The Java compiler detects many problems that, in other languages, would show up only at run time. As for the second point, anyone who has spent hours chasing memory corruption caused by a pointer bug will be very happy with this feature of Java.If you are coming from a language like Visual Basic that doesn't explicitly use pointers, you are probably wondering why this is so important. C programmers are not so lucky. They need pointers to access strings, arrays, objects, and even files. In Visual Basic, you do not use pointers for any of these entities, nor do you need to worry about memory allocation for them. On the other hand, many data structures aredifficult to implement in a pointerless language. Java gives you the best of both worlds. You do not need pointers for everyday constructs like strings and arrays. You have the power of pointers if you need it, for example, for linked lists. And you always have complete safety, because you can never access a bad pointer, make memory allocation errors, or have to protect against memory leaking away.5. SecureJava is intended to be used in networked/distributed environments. Toward that end, a lot of emphasis has been placed on security. Java enables the construction of virus-free, tamper-free systems.In the first edition of Core Java we said: "Well, one should 'never say never again,'" and we turned out to be right. Not long after the first version of the Java Development Kit was shipped, a group of security experts at Princeton University found subtle bugs in the security features of Java 1.0. Sun Microsystems has encouraged research into Java security, making publicly available the specification and implementation of the virtual machine and the security libraries. They have fixed all known security bugs quickly. In any case, Java makes it extremely difficult to outwit its security mechanisms. The bugs found so far have been very technical and few in number. From the beginning, Java was designed to make certain kinds of attacks impossible, among them:∙Overrunning the runtime stack—a common attack of worms and viruses Corrupting memory outside its own process space Reading or writing files without permission.∙A number of security features have been added to Java over time. Since version1.1, Java has the notion of digitally signed classesWith a signed class, you can be sure who wrote it. Any time you trust the author of the class, the class can be allowed more privileges on your machine.6. Architecture NeutralThe compiler generates an architecture-neutral object file format—the compiled code is executable on many processors, given the presence of the Java runtime system.The Java compiler does this by generating bytecode instructions which have nothing to do with a particular computerarchitecture. Rather, they are designed to be both easy to interpret on any machine and easily translated into native machine code on the fly.This is not a new idea. More than 20 years ago, both Niklaus Wirth's original implementation of Pascal and the UCSD Pascal system used the same technique. Of course, interpreting bytecodes is necessarily slower than running machine instructions at full speed, so it isn't clear that this is even a good idea. However, virtual machines have the option of translating the most frequently executed bytecode sequences into machine code, a process called just-in-time compilation. This strategy has proven so effective that even Microsoft's .NET platform relies on a virtual machine.The virtual machine has other advantages. It increases security because the virtual machine can check the behavior of instruction sequences. Some programs even produce bytecodes on the fly, dynamically enhancing the capabilities of a running program.7. PortableUnlike C and C++, there are no "implementation-dependent" aspects of the specification. The sizes of the primitive data types are specified, as is the behavior of arithmetic on them.For example, an int in Java is always a 32-bit integer. In C/C++, int can mean a 16-bit integer, a 32-bit integer, or any other size that the compiler vendor likes. The only restriction is that the int type must have at least as many bytes as a short int and cannot have more bytes than a long int. Having a fixed size for number types eliminates a major porting headache. Binary data is stored and transmitted in a fixed format, eliminating confusion about byte ordering. Strings are saved in a standard Unicode format.The libraries that are a part of the system define portable interfaces. For example, there is an abstract Window class and implementations of it for UNIX, Windows, and the Macintosh.As anyone who has ever tried knows, it is an effort of heroic proportions to write a program that looks good on Windows, the Macintosh, and 10 flavors of UNIX. Java1.0 made the heroic effort, delivering a simple toolkit that mapped common user interface elements to a number of platforms.Unfortunately, the result was a library that, with a lot of work, could give barely acceptable results on different systems. (And there were often different bugs on the different platform graphics implementations.) But it was a start. There are many applications in which portability is more important than user interface slickness, and these applications did benefit from early versions of Java. By now, the user interface toolkit has been completely rewritten so that it no longer relies on the host user interface. The result is far more consistent and, we think, more attractive than in earlier versions of Java.8. InterpretedThe Java interpreter can execute Java bytecodes directly on any machine to which the interpreter has been ported. Since linking is a more incremental and lightweight process, the development process can be much more rapid and exploratory.Incremental linking has advantages, but its benefit for the development process is clearly overstated. In any case, we have found Java development tools to be quite slow. If you are used to the speed of the classic Microsoft Visual C++ environment, you will likely be disappointed with the performance of Java development environments. (The current version of Visual Studio isn't as zippy as the classic environments, however. No matter what languageyou program in, you should definitely ask your boss for a faster computer to run the latest development environments. )9. High PerformanceWhile the performance of interpreted bytecodes is usually more than adequate, there are situations where higher performance is required. The bytecodes can be translated on the fly (at run time) into machine code for the particular CPU the application is running on.If you use an interpreter to execute the bytecodes, "high performance" is not the term that we would use. However, on many platforms, there is also another form ofcompilation, the just-in-time (JIT) compilers. These work by compiling the bytecodes into native code once, caching the results, and then calling them again if needed. This approach speeds up commonly used code tremendously because one has to do the interpretation only once. Although still slightly slower than a true native code compiler, a just-in-time compiler can give you a 10- or even 20-fold speedup for some programs and will almost always be significantly faster than an interpreter. This technology is being improved continuously and may eventually yield results that cannot be matched by traditional compilation systems. For example, a just-in-time compiler can monitor which code is executed frequently and optimize just that code for speed.10. MultithreadedThe enefits of multithreading are better interactive responsiveness and real-time behavior.if you have ever tried to do multithreading in another language, you will be pleasantly surprised at how easy it is in Java. Threads in Java also can take advantage of multiprocessor systems if the base operating system does so. On the downside, thread implementations on the major platforms differ widely, and Java makes no effort to be platform independent in this regard. Only the code for calling multithreading remains the same across machines; Java offloads the implementation of multithreading to the underlying operating system or a thread library. Nonetheless, the ease of multithreading is one of the main reasons why Java is such an appealing language for server-side development.11. DynamicIn a number of ways, Java is a more dynamic language than C or C++. It was designed to adapt to an evolving environment. Libraries can freely add new methods and instance variables without any effect on their clients. In Java, finding out run time type information is straightforward.This is an important feature in those situations in which code needs to be added to a running program. A prime example is code that is downloaded from the Internet to run in a browser. In Java 1.0, finding out runtime type information was anything but straightforward, but current versions of Java give the programmer full insight intoboth the structure and behavior of its objects. This is extremely useful for systems that need to analyze objects at run time, such as Java GUI builders, smart debuggers, pluggable components, and object databases.Java技术介绍Java是一种程序设计平台Java是一种优秀的程序设计语言。
计算机专业毕业设计论文外文文献中英文翻译——java对象
1 . Introduction To Objects1.1The progress of abstractionAll programming languages provide abstractions. It can be argued that the complexity of the problems you’re able to solve is directly related to the kind and quality of abstraction。
By “kind” I mean,“What is it that you are abstracting?” Assembly language is a small abstraction of the underlying machine. Many so—called “imperative” languages that followed (such as FORTRAN,BASIC, and C) were abstractions of assembly language。
These languages are big improvements over assembly language,but their primary abstraction still requires you to think in terms of the structure of the computer rather than the structure of the problem you are trying to solve。
The programmer must establish the association between the machine model (in the “solution space,” which is the place where you’re modeling that problem, such as a computer) and the model of the problem that is actually being solved (in the “problem space,” which is the place where the problem exists). The effort required to perform this mapping, and the fact that it is extrinsic to the programming language,produces programs that are difficult to write and expensive to maintain,and as a side effect created the entire “programming methods” industry.The alter native to modeling the machine is to model the problem you’re trying to solve。
(完整word版)JAVA外文文献+翻译
Java and the InternetIf Java is, in fact, yet another computer programming language, you may question why it is so important and why it is being promoted as a revolutionary step in computer programming. The answer isn't immediately obvious if you’re comin g from a traditional programming perspective. Although Java is very useful for solving traditional stand—alone programming problems, it is also important because it will solve programming problems on the World Wide Web。
1.Client—side programmingThe Web’s in itial server—browser design provided for interactive content, but the interactivity was completely provided by the server. The server produced static pages for the client browser, which would simply interpret and display them。
Basic HTML contains simple mechanisms for data gathering: text-entry boxes, check boxes, radio boxes, lists and drop—down lists, as well as a button that can only be programmed to reset the data on the form or “submit” the data on the form back to the server。
javaweb论文参考文献(2020年精选91个)
Java Web,是用Java技术来解决相关web互联网领域的技术栈。
web包括:web服务端和web客户端两部分。
Java在客户端的应用有java applet,不过使用得很少,Java在服务器端的应用非常的丰富,比如Servlet,JSP和第三方框架等等。
Java技术对Web领域的发展注入了强大的动力。
下面是javaweb论文参考文献91个,供大家参考阅读。
javaweb论文参考文献一:[1]邓明杨,李忠雄。
基于JAVA Web技术的网上书城的设计与实现[J].计算机产品与流通,2020(05):159-160.[2]陶林,瞿少成,易宇凡,杨军文,郝超。
一种模拟农场环境监测与灌溉控制的教育物联网系统实现[J].电子测量技术,2019,42(24):81-85.[3]苗立志,崔进东,孙敏,崔文俊。
面向北斗CORS运行数据的动态监测系统[J].南京邮电大学学报(自然科学版),2020,40(01):70-74.[4]汪永松。
JavaWeb开发技巧之项目模板[J].电脑编程技巧与维护,2020(02):3-8+16.[5]武奕含。
浅谈计算机专业学生“学习高原”现象[J].数字通信世界,2020(02):270.[6]薛茹。
基于JavaWeb的图书购物网站的设计与实现研究[J].南方农机,2020,51(02):217.[7]李光明,房靖力。
基于JavaWeb的推荐数据后台管理系统的设计与实现[J].电脑知识与技术,2020,16(03):66-68.[8]匡少华,丁昊,赵正平。
基于Javaweb的大学生食堂外卖平台的设计与实现[J].信息与电脑(理论版),2020,32(01):91-94.[9]刘岑松,罗小巧,洪习欢。
基于物联网的智能浇花系统[J].电子测量技术,2020,43(01):176-180.[10]聂毓谣。
基于数据库的员工考勤系统设计与实现[J].电脑知识与技术,2020,16(01):56-58+87.[11]季昆,孟丽丽,薛迁,孙晓伟,王才华。
Java编程语言外文翻译、英汉互译、中英对照
文档从互联网中收集,已重新修正排版,word格式支持编辑,如有帮助欢迎下载支持。
外文翻译原文及译文学院计算机学院专业计算机科学与技术班级学号姓名指导教师负责教师Java(programming language)Java is a general-purpose, concurrent, class-based, object-oriented computer program- -ming language that is specifically designed to have as few implementation dependencies as possible. It is intended to let application developers "write once, run anywhere" (WORA), meaning that code that runs on one platform does not need to be recompiled to run on another. Java applications are typically compiled to byte code (class file) that can run on any Java virtual machine(JVM) regardless of computer architecture. Java is, as of 2012, one of the most popular programming languages in use, particularly for client-server web applications, with a reported 10 million users. Java was originally developed by James Gosling at Sun Microsystems (which has since merged into Oracle Corporation) and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++, but it has fewer low-level facilities than either of them.The original and reference implementation Java compilers, virtual machines, and class libraries were developed by Sun from 1991 and first released in 1995. As of May 2007, in compliance with the specifications of the Java Community Process, Sun relicensed most of its Java technologies under the GNU General Public License. Others have also developed alternative implementations of these Sun technologies, such as the GNU Compiler for Java and GNU Classpath.Java is a set of several computer software products and specifications from Sun Microsystems (which has since merged with Oracle Corporation), that together provide a system for developing application software and deploying it in across-platform computing environment. Java is used in a wide variety of computing platforms from embedded devices and mobile phones on the low end, to enterprise servers and supercomputers on the high end. While less common, Java appletsare sometimes used to provide improved and secure functions while browsing the World Wide Web on desktop computers.Writing in the Java programming language is the primary way to produce code that will be deployed as Java bytecode. There are, however, byte code compilers available forother languages such as Ada, JavaScript, Python, and Ruby. Several new languages have been designed to run natively on the Java Virtual Machine (JVM), such as Scala, Clojure and Groovy.Java syntax borrows heavily from C and C++, but object-oriented features are modeled after Smalltalk and Objective-C. Java eliminates certain low-level constructs such as pointers and has a very simple memory model where every object is allocated on the heap and all variables of object types are references. Memory management is handled through integrated automatic garbage collection performed by the JVM.An edition of the Java platform is the name for a bundle of related programs from Sun that allow for developing and running programs written in the Java programming language. The platform is not specific to any one processor or operating system, but rather an execution engine (called a virtual machine) and a compiler with a set of libraries that are implemented for various hardware and operating systems so that Java programs can run identically on all of them. The Java platform consists of several programs, each of which provides a portion of its overall capabilities. For example, the Java compiler, which converts Java source code into Java byte code (an intermediate language for the JVM), is provided as part of the Java Development Kit (JDK). The Java Runtime Environment(JRE), complementing the JVM with a just-in-time (JIT) compiler, converts intermediate byte code into native machine code on the fly. An extensive set of libraries are also part of the Java platform.The essential components in the platform are the Java language compiler, the libraries, and the runtime environment in which Java intermediate byte code "executes" according to the rules laid out in the virtual machine specification.In most modern operating systems (OSs), a large body of reusable code is provided to simplify the programmer's job. This code is typically provided as a set of dynamically loadable libraries that applications can call at runtime. Because the Java platform is not dependent on any specific operating system, applications cannot rely on any of the pre-existing OS libraries. Instead, the Java platform provides a comprehensive set of its own standard class libraries containing much of the same reusable functions commonly found in modern operating systems. Most of the system library is also written in Java. For instance, Swing library paints the user interface and handles the events itself, eliminatingmany subtle differences between how different platforms handle even similar components.The Java class libraries serve three purposes within the Java platform. First, like other standard code libraries, the Java libraries provide the programmer a well-known set of functions to perform common tasks, such as maintaining lists of items or performing complex string parsing. Second, the class libraries provide an abstract interface to tasks that would normally depend heavily on the hardware and operating system. Tasks such as network access and file access are often heavily intertwined with the distinctive implementations of each platform. The and java.io libraries implement an abstraction layer in native OS code, then provide a standard interface for the Java applications to perform those tasks. Finally, when some underlying platform does not support all of the features a Java application expects, the class libraries work to gracefully handle the absent components, either by emulation to provide a substitute, or at least by providing a consistent way to check for the presence of a specific feature.The success of Java and its write once, run anywhere concept has led to other similar efforts, notably the .NET Framework, appearing since 2002, which incorporates many of the successful aspects of Java. .NET in its complete form (Microsoft's implementation) is currently only fully available on Windows platforms, whereas Java is fully available on many platforms. .NET was built from the ground-up to support multiple programming languages, while the Java platform was initially built to support only the Java language, although many other languages have been made for JVM since..NET includes a Java-like language called Visual J# (formerly named J++) that is incompatible with the Java specification, and the associated class library mostly dates to the old JDK 1.1 version of the language. For these reasons, it is more a transitional language to switch from Java to the .NET platform, than a first class .NET language. Visual J# was discontinued with the release of Microsoft Visual Studio 2008. The existing version shipping with Visual Studio 2005will be supported until 2015 as per the product life-cycle strategy.In June and July 1994, after three days of brainstorming with John Gage, the Director of Science for Sun, Gosling, Joy, Naughton, Wayne Rosing, and Eric Schmidt, the team re-targeted the platform for the World Wide Web. They felt that with the advent of graphical web browsers like Mosaic, the Internet was on its way to evolving into the samehighly interactive medium that they had envisioned for cable TV. As a prototype, Naughton wrote a small browser, Web Runner (named after the movie Blade Runner), later renamed Hot Java.That year, the language was renamed Java after a trademark search revealed that Oak was used by Oak Technology. Although Java 1.0a was available for download in 1994, the first public release of Java was 1.0a2 with the Hot Java browser on May 23, 1995, announced by Gage at the Sun World conference. His announcement was accompanied by a surprise announcement by Marc Andreessen, Executive Vice President of Netscape Communications Corporation, that Netscape browsers would be including Java support. On January 9, 1996, the Java Soft group was formed by Sun Microsystems to develop the technology.Java编程语言Java是一种通用的,并发的,基于类的并且是面向对象的计算机编程语言,它是为实现尽可能地减少执行的依赖关系而特别设计的。
Java技术与Web设计外文文献翻译
文献信息文献标题:A Comparative Study of Top Web Design Models that are using Java Technologies(使用Java技术的顶级Web设计模型的比较研究)文献作者及出处:Sathyaseelan B, Cordova R S. A Comparative Study of Top Web Design Models that are using Java Technologies[J].International Journal of Innovations and Advancement in Computer Science. 2016,5(5):41-44字数统计:英文1614单词,8806字符;中文2779汉字外文文献A Comparative Study of Top Web Design Models that areusing Java TechnologiesAbstract In today's professional workplace, enterprise applications are complex, adaptable, distributed, part-based, and mission-critical. They might be conveyed as an assortment of platforms across corporate systems, intranets, or the Internet. They are information driven, easy to use, and should meet stringent prerequisites for security, organization, and support. To put it plainly, they are highly complex systems. Various enterprise applications have been in the market today and there are numerous methods available for developing enterprise applications.This paper discusses the major differences between two competing design models for developing Web applications using Java technologies which are Struts and Java Server Faces (JSF). Struts is an open source java framework and is an action-based framework.On the other hand, JSF is a new technology that supports ready-to-use components for rapid Web application development. These two technologies will be analyzed depending on the factors such as the controller flexibility or event handling, navigation, page development, integration and extensibility.Keywords: web design models, Struts, Java Server Faces and Java technologiesI.IntroductionA STRUT is a web application system that has been popular over Java Servlets. It envelops the ordinarily utilized MVC design pattern. A STRUT automates normal tasks, liberating up to explore more of the Action- to-result pages mapping utilizing SML-based configurations. The system makes the progress level subtle elements of the usage of Web-based applications and gives a bit of structural software. JavaServer Faces (JSF) abridges the development of web application user interfaces, usually by defining a user interface component model tied to a well-defined request processing lifecycle. It characterizes a set of UI components— basically, a balanced mapping of the html structure component set along with some extras—that could a be utilized as an application programming interface for extending and modifying standard components or developing new components.II.Key DifferencesThe figures below illustrate the key differences between a STRUTS and JSF request-response scenario. This is necessary in order to fully understand the architecture of each web design models.Figure 1. Struts Request-Response ScenarioIn figure 1, the client sends request to server through a web-browser for aparticular resource. This request is forwarded to the server through a Controller. A servlet goes about as a controller, accepting all requests from the customer. The servlet hands off the request to a different business layer for handling. When processing is finished, the servlet advances or diverts the request to a JSP, which is exclusively in charge of creating the following view for the client. There is no business logic within the JSP.Figure 2. JSF Request-Response ScenarioIn figure 2, the server handles requests from the client, starting from an initial request to a postback request. When a client makes an underlying request for a page, it is asking for the page for the first time. When a client executes a postback, it presents the structure contained on a page that was beforehand stacked into the program as a result of executing an underlying request. When the life cycle handles an underlying request, it just executes the restore view and renders response phases in light of the fact that there is no client information or activities to prepare. Then again, when the life cycle handles a postback, it executes the majority of the phases.III.MethodologyIn this study we will compare JSF and Struts. We will create two modelsemploying the JSF and Struts request-response scenario. JSF is a “component” framework while Struts is an “action” framework.This paper compares and evaluates the ease of application development and the performance of two design models (Struts and JSF) by presenting the two design models and critically analyzes each technology.IV.ChallengesWeb Development ChallengesThe challenges in Web development are much more than the application development. The main challenge is in hosting the application over a webserver and then handling the network issues while accessing those via network. The performances of the web-based application are based on the network availability and its speed. These are not challenges for desktop applications as they run on the local host and the resources are based only on that system.Challenges in STRUTSDespite the fact that Struts accompanies a rundown of remarkable elements however it is important not to neglect the few negative applications about Struts and would require loads of improvements.Greater expectation to learn and adapt - To utilize MVC with STRUTS, you must be alright with the standard JSP, Servlet APIs and a substantial and elaborate system.Poor documentation - Compared to the standard servlet and JSP APIs, STRUTS has less online resources, and some first-time clients locate the online Apache documentation confusing and inadequately sorted out.Less straightforward -With STRUTS applications, there is significantly more going ahead in the background than with ordinary Java-based Web applications which makes it hard to comprehend the system.Challenges in JSFJSF is a very powerful innovation for creating Java-based web applications. It is intended to improve the development of client interfaces for Java Enterprise Edition (Java EE) applications via programmed handling of low level HTTP requests andclient information processing. JSF utilizes a part based model for web advancement. Utilizing the visual JSF web application instrument offered by NetBeans () integrated development environment (IDE), segments can be actually "painted" on a virtual JSF page by relocating them from a palette of JSF segment library.Event handlers can then be characterized for every part the same route concerning creating standalone Java graphical user interface (GUI) application. Route standards are determined for every page from a central XML arrangement document (faces-config.xml). Client activities on a web interface will trigger an event which in return figures out which page is to be shown along the rules specified on that page.This methodology encourages measured and adaptable design, making web application development much more straightforward and faster.The route decides determined for that page. This methodology encourages measured and adaptable configuration, making web application advancement much less difficult and speedier.V.AnalysisIn this study, STRUTS and JSF were analyzed in terms of their controller flexibility or event handling, navigation, page development, integration and extensibility. This is important to compare each web design model and present the advantages and disadvantages of each technology.Controller Flexibility/Event HandlingController is considered as the heart of the Struts. It uses the Front Controller Pattern and Command Pattern. A single servlet takes a request, and then translates HTTP parameters into a Java ActionForm, and passes the ActionForm into a Struts Action class. The URI designates which Action class need to be executed. The Struts framework has one single event handler for the HTTP request. When the request is met by the event handler, the Action returns the result back to the front controller. This in turn will be used to choose the navigation destination.Controller Pattern is been used by the JSF. Each face request goes through asingle servlet, whose responsibility is to get a faces page with components. It will then trigger the events for each component and render the components using a render toolkit. It is also possible to bound the components to the data from its model. JSF have several event handlers on a page while Struts is geared to one event per request. In addition, with Struts, the ActionForms have to extend Struts classes, creating another layer of complicated coding while JSF gives the ability to peg into the model without breaking layering.NavigationNavigation is a key feature of both Struts and JSF. There are 2 types of navigation: static navigation - when the output of a particular page is known so that it is very easy to predict its expected output; and dynamic navigation – when the output is unpredictable and some business logic determines the output of that particular page. Both frameworks have a declarative navigation model and define navigation using rules inside their XML configuration file. Both JSF and Struts support both types of navigation.Page DevelopmentJSF was built with component models which support RAD development, while struts don’t have that support. The Struts framework provides custom libraries to peg into Action Forms and offers some utilities. JSF provides the ability to build components from a variety of view technologies and does it in such a way to be component based.IntegrationStruts are model neutral, so there is no special hook into a model layer. The page data has to be moved from the Action Form to another Model input format which requires heavy complicated coding. The ActionForm class, provides an extra layer of tedious coding and state transition.JSF, on the other hand, encapsulates and hides the details of any data inside the component tree. Data grids and similar rich components can be bound to any Java class. This allows the combination of JSF and SDO which are powerful RAD development.ExtensibilityBoth Struts and JSF offers the extension of framework to meet expanding requirements. Struts have RequestProcessor class that has various callback methods and is the major grip for struts throughout the life-cycle of a request. JSF also have similar functionality to outspread special life-cycle interfaces. Apart from this, JSF totally decouples the render phase from the controller. This considered as on of the main important feature of JSF that Struts does not incorporate.VI.ConclusionJSF is a much more flexible framework while struts is a sturdy framework and works well. JSF is a strong framework because of its flexible controller and navigation. Furthermore, JSF is built with integration and extensibility. From a strategic direction and programming model, JSF can be a target of new applications.中文译文使用Java技术的顶级Web设计模型的比较研究摘要在当今的专业工作环境中,企业应用程序是复杂的、可适应的、分布式的、基于部件的和任务关键的。
外文翻译---JSP简介
JSP introducedJSP (Java Server Pages) is Corporation initiates one kind of dynamic homepage technical standard by Sun Microsystems which, many companies participation establishes together. This technology has provided for the foundation demonstration dynamic production content Web page simple and direct and the fast method. The JSP technology design goal is makes the structure to be easier based on the Webapp lication procedure and quickly, but these application procedures can with each kind of Web server, using the server, the browser and the development kit work together. The JSP standard is the Web server, applies the server, the transaction system, as well as between the development kit supplier the broad cooperation result. In the traditional homepage HTML document (*htm, * html) center joins the Java procedure fragment (Scriptlet) and the JSP mark (tag), constituted the JSP homepage (* jsp). The Web server when meets visits the JSP homepage the request, first carries out procedure fragment, then will carry out the result to return by the HTML form for the customer. The procedure fragment may operate the database, again the directional homepage as well as transmits email and so on, this is a function which the establishment dynamic website needs. All procedures operation all in the server end execution, in the network transmits the result which only is obtains for the customer end, is lowest to the client browser request, may realize does not have Plugin, does not have ActiveX, non- Java Applet, even does not have Frame.JSP简介J SP(Java Server Pages)是由Sun Microsystems公司倡导、许多公司参与一起建立的一种动态网页技术标准。
计算机 JSP web 外文翻译 外文文献 英文文献
外文资料所译外文资料:①作者:Dan Malks②书名:Professional JSP③出版时间: 2000.7.26④所译章节: Chapter 1212.1IntroductoryGood Web application design tries to separate business objects, presentation, and manipulation of the objects into distinct layers. One benefit of using JavaServer Pages technology is that it allows us to separate the role of a Web designer more clearly from that of a software developer. While on a small-scale project, one individual may occupy both roles, on a larger project, they are likely to be separate and it is beneficial to separate their workflows as much as possible. Designing the architecture for your Web application is crucial to this separation.12.2 JSP architectureWe will examine a variety of ways to architect a system with JavaServer Pages, servlets, and JavaBeans. We will see a series of different architectures, each a development of the one before. The diagram below shows this process in outline; the individual parts of the diagram will be explained in turn later in this article.JSP architecture:When Sun introduced Java Server Pages, some were quick to claim that servlets had been replaced as the preferred request handling mechanism in Web-enabled enterprise architectures. Although JSP is a key component of the Java 2 Platform Enterprise Edition (J2EE) specification, serving as the preferred request handler and response mechanism, we must investigate further to understand its relationship with servlets.Other sections of Professional JSP explain the implementation details of JSP source translation and compilation into a servlets. Understanding that JSP is built on top of the servlet API, and uses servlet semantics, raises some interesting questions. Should we no longer develop stand-alone servlets in our Web-enabled systems? Is there some way to combine servlets and JSPs? If so, where do we place our Java code? Are there any other components involved in the request processing, such as JavaBeans? If so, where do they fit into the architecture and what type of role do they fulfill?It is important to understand that, although JSP technology will be a powerful successor to basic servlets, they have an evolutionary relationship and can be used in a cooperative and complementary manner.Given this premise, we will investigate how these two technologies, each a Java Standard Extension, can be used co-operatively along with other components, such as JavaBeans, to create Java-based Web-enabled systems. We will examine architecturalissues as they relate to JSP and servlets and discuss some effective designs while looking at the tradeoffs of each. Before jumping directly into a discussion of specific architectures, though, we will briefly examine the need to develop a variety of architectures.12.3 Code factoring and role separationOne of the main reasons why the JavaServer Pages technology has evolved into what it is today (and it's still evolving) is the overwhelming technical need to simplify application design by separating dynamic content from static template display data. The foundation for JSP was laid down with the initial development of the Java Web Server from Sun, which used page compilation and focused on embedding HTML inside Java code. As applications came to be based more on business objects and n-tier architectures, the focus changed to separating HTML from Java code, while still maintaining the integrity and flexibility the technology provided.In Chapter 5, JSP Sessions, in Professional JSP, we saw how beans and objects can be bound to different contexts just by defining a certain scope. Good application design builds on this idea and tries to separate the objects, the presentation, and the manipulation of the objects into distinct, distinguishable layers.Another benefit of using JSP is that it allows us to more cleanly separate the roles of a Web production/HTML designer individual from a software developer. Remember that a common development scenario with servlets was to embed the HTML presentation markup within the Java code of the servlet itself, which can be troublesome. In our discussion, we will consider the servlet solely as a container for Java code, while our entire HTML presentation template is encapsulated within a JSP source page. The question then arises as to how much Java code should remain embedded within our JSP source pages, and if it is taken out of the JSP source page, where should it reside?Let's investigate this further. On any Web-based project, multiple roles and responsibilities will exist. For example, an individual who designs HTML pages fulfills a Web production role while someone who writes software in the Java programming language fulfills a software development role.On small-scale projects these roles might be filled by the same individual, or two individuals working closely together. On a larger project, they will likely be filled by multiple individuals, who might not have overlapping skill sets, and are less productive if made too dependent on the workflow of the other.If code that could be factored out to a mediating servlet is included instead within HTML markup, then the potential exists for individuals in the software development role and those in the Web production role to become more dependent than necessary on the progress and workflow of the other. Such dependencies may create a more error-prone environment, where inadvertent changes to code by other team members become more common.This gives us some insight into one reason why we continue to develop basic servlets: they are an appropriate container for our common Java code that has been factored out of our JSP pages, giving our software development team an area of focus that is as loosely coupled to our JSP pages as possible. Certainly, there will be a need for these same individuals to work with the JSP source pages, but the dependency is reduced, and these pages become the focus of the Web-production team instead. Of course, if the same individual fulfills both roles, as is typical on a smaller project, such dependencies are not a major concern.So, we should try to minimize the Java code that we include within our JSP page, in order to uphold this cleaner separation of developer roles. As we have discussed, some of this Java code is appropriately factored to a mediating servlet. Code that is common to multiple requests, such as authentication, is a good candidate for a mediating servlet. Such code is included in one place, the servlet, instead of potentially being cut and pasted into multiple JSPs.We will also want to remove much of our business logic and data access code from our JSP page and encapsulate it within JavaBeans, called worker or helper beans. We start to see a pattern of code movement from our JSP into two areas: a servlet (or JSP) that sits in front of the main JSP, and JavaBeans that sit in back. We refer to this common pattern as "Factor Forward -- Factor Back," as shown in the figure below:Factor Forward -- Factor Back:Another way to think about what code should be localized and encapsulated is that our JSP page should reveal as little as possible of our Java code implementation details.Rather, the page should communicate our intent by revealing the delegating messages we send to worker beans, instructing them to get state from a model, or to complete some business processing.12.4 Redirecting and forwardingRedirecting and forwarding requests in JSPs and servlets takes place often, and it is important to understand the subtle difference between these two mechanisms even though they achieve the same goal (that is, a client asks for a resource on the server and a different resource is served to it):●When a servlet or JSP resource chooses to redirect the client (using aresponse.sendRedirect(url)) the request object does not reach the second resource directly since the underlying implementation is an HTTP redirect.The server sends an HTTP 302 message back to the client telling it that the resource has moved to another URL, and that the client should access it there.The bottom line is that the lifecycle of the initial request object that was accessed in the first JSP terminates with the end of the service method in the first JSP, or with the reply from the server.●In a forward mechanism the request object is forwarded to the second resource,thus maintaining any object bindings to the request and its state, without a round trip to the client on the network. This allows the first JSP to do some work internally and then send information to the second JSP asking it to do itsbit. (Servlets used a chaining mechanism to do this). See Chapter 5, JSP Sessions, in Professional JSP to get a clearer picture of scope. JSPs and servlets can use the forwarding mechanism to delegate tasks among themselves, in the process of separating dynamic and static content.Now, let's investigate how we build these systems.12.5 ArchitecturesBefore discussing specific architectures that we can use to build systems with servlets and JSP, it is worth mentioning two basic ways of using the JSP technology. Each of the architectures discussed in this chapter will be based on one of these approaches:●The first method is referred to here as the page-centric (or client-server)approach. This approach involves request invocations being made directly to JSP page.●In the second method, the dispatcher (or n-tier) approach, a basic servlet orJSP acts as a mediator or controller, delegating requests to JSP pages and JavaBeans.We will examine these approaches in light of a simple example, which will evolve to satisfy the requirements of various scenarios. The initial scenario involves providing a Web interface for guessing statistics about a soon-to-be-born baby. The guesses are stored, and can be reviewed later by the parents, to see who has guessed the closest. As the requirement scenarios become more sophisticated, such as adding the desire for a persistence mechanism, the solution scenarios will become more sophisticated, as well. Thus, our example will evolve and we will gain an understanding of how the various architectures that we discuss will help us build a system that satisfies these requirements in an elegant and effective manner.12.6 The page-centric approachApplications built using a client-server approach have been around for some time; they consist of one or more application programs running on client machines and connecting to a server-based application to work. (A good example would be a PowerBuilder or Oracle Forms-based system.) CGIs and pre-servlet applications were generally based on this simple 2-tier model, and with the introduction of servlets, 2-tier applications could also be created in Java.This model allows JSPs or servlets direct access to some resource like a database or legacy application to service a client's request: the early JSP specifications termed this a "Model 1" programming approach. The JSP page is where the incoming request is intercepted and processed, and the response is sent back to the client;JSPs only differed from servlets in this scenario by providing cleaner code and separating code from the content by placing data access in beans.Model 1 programming approach:The advantage of such an approach is that it is siple to program,and allows the page author to Generate dynamic content easily,based upon the request and the state resources.However this architecture does not scale up well for a large number of simultaneous clients since there would be a significant amount of request processing to be performed,and each request must establish or share a potentially scarce/expensive connection to the resource in question.(A good example would be JDBC connectons in servlets or JSPs and the need for connection pools.) Indiscriminate usage of this architecture usually leads to a significant amount of Java code embedded within the JSP page,this may not seem to be much of a problem for Java developers but it is certainly an issue if the JSP pages are maintained by designers:the code tends to get in the designe’s way,and you run the risk of your code becoming corrupted when others are tweaking the look and feel.译文12.1前言好的Web应用设计试图将业务对象,简报以及操作对象分为不同的层面。
java实现英文翻译程序
java实现英⽂翻译程序本⽂实例为⼤家分享了java实现英⽂翻译程序的具体代码,供⼤家参考,具体内容如下1.功能简介将⽂本⽂件中的英⽂转换为对应的中⽂词库如下:源⽂件:翻译后的⽂件:输⼊源⽂件路径,将翻译后的内容输出到result.txt⽂件中。
2.重要技术(1)如何载⼊词库⽂件因为词库⽂件是 kry=value的形式,所有可以⽤到Properties类的load函数(2)如何将源⽂件中的⼀段英⽂分理处⼀个个的单词可以⽤StringTokenizer类(3)如何进⾏翻译直接⽤中⽂替换相应的英⽂3.项⽬结构(4)代码编写①FileLoader类/*⽂件载⼊类,将源⽂件中的内容输出到字节数组中*/package zhidao3_2;import java.io.FileInputStream;import java.io.File;public class FileLoad {public static byte[] getContent(String fileName)throws Exception{File file = new File(fileName);if(!file.exists()){System.out.println("输⼊有误,该⽂件不存在");}FileInputStream fis = new FileInputStream(file);int length = (int)file.length();byte[] data = new byte[length];fis.read(data);fis.close();return data;}}②TxtTrans类/*⽂件翻译,将字节数组变为字符串,分离出其中的单词,然后翻译为对应的汉字,去掉空格,变为字符串*/ package zhidao3_2;import java.util.StringTokenizer;import java.util.Properties;import java.io.*;public class TxtTrans {private Properties pps;public TxtTrans(){loadCiku();}public void loadCiku(){pps = new Properties();try{FileReader fis = new FileReader("g:/ciku.txt");//以字符载⼊时没有乱码,以字节载⼊时出现了乱码pps.load(fis);fis.close();}catch(Exception ex){ex.printStackTrace(System.out);System.out.println("载⼊词库时出错");}//System.out.println(pps.get("china")) ;}public String trans(byte[] data){String srcTxt = new String(data);String dstTxt = srcTxt;String delim = " ,.!\n\t"; //分隔符可以指定StringTokenizer st = new StringTokenizer(srcTxt,delim,false);String sub,lowerSub,newSub;//int i=0;while(st.hasMoreTokens()){sub = st.nextToken(); //分割出的⼀个个单词lowerSub = sub.toLowerCase();//统⼀转换为⼩写,这样可以简化词库//System.out.println(sub);newSub = pps.getProperty(lowerSub);if(newSub != null){ //如果找到了匹配的汉字,则进⾏替换dstTxt = dstTxt.replaceFirst(sub, newSub); //只替换第⼀个,即只替换了当前的字符串,否则容易造成ch我na的例⼦ //System.out.println(dstTxt);}}return dstTxt.replaceAll(" ", ""); //去掉空格}}③FileOutput类/*将字符串输出到⽂件*/package zhidao3_2;import java.io.File;import java.io.FileOutputStream;public class FileOutput {public static void output(String text,String fileName)throws Exception{File file = new File(fileName);FileOutputStream fos = new FileOutputStream(file);fos.write(text.getBytes());fos.close();}}④主函数package zhidao3_2;import javax.swing.JOptionPane;public class Main {public static void main(String[] args) {String srcFile = JOptionPane.showInputDialog("输⼊源⽂件");try{byte[] data = FileLoad.getContent(srcFile);TxtTrans tt = new TxtTrans();String dString = tt.trans(data);FileOutput.output(dString, "g:/result.txt");}catch(Exception ex){JOptionPane.showMessageDialog(null, "操作异常");System.exit(1);}JOptionPane.showMessageDialog(null, "翻译完毕");}}最后的项⽬结构如下:以上就是本⽂的全部内容,希望对⼤家的学习有所帮助,也希望⼤家多多⽀持。
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外文原文Database Development ProcessBased on information engineering information systems planning database is a source of development projects. These new database development projects is usually in order to meet the strategic needs of organizations, such as improving customer support, improve product and inventory management, or a more accurate sales forecast. However, many more database development project is the bottom-up approach emerging, such as information system user needs specific information to complete their work, thus beginning a project request, and as other information systems experts found that organizations need to improve data management and begin new projects. Bottom-up even in the circumstances, to set up an enterprise data model is also necessary to understand the existing database can provide the necessary data, otherwise, the new database, data entities and attributes can be added to the current data resources to the organization.Both the strategic needs or operational information needs of each database development projects normally concentrated in a database. Some projects only concentrated in the database definition, design and implementation of a database, as a follow-up to the basis of the development of information systems. However, in most cases, the database and associated information processing function as a complete information systems development project was part of the development.one. System Development Life CycleGuide management information system development projects is the traditional process of system development life cycle (SDLC). System development life cycle is an organization of the database designers and programmers information system composed of the Panel of Experts detailed description, development, maintenance and replacement of the entire information system steps. This process is because Waterfall than for every step into the adjacent the next step, that is, the information system is a specification developed by a piece of land, every piece of the output is under an input. However shownin the figure, these steps are not purely linear, each of the steps overlap in time (and thus can manage parallel steps), but when the need to reconsider previous decisions, but also to roll back some steps ahead. (And therefore water can be put back in the waterfall!) The system development life cycle including each stage and database development-related activities, therefore, the question of database management systems throughout the entire development process. In Figure 5 we repeat of the system development life cycle stage of the seven, and outlines the common database at each stage of development activities. Please note that the systems development life cycle stages and database development steps exists between the relationship between the concept of modeling data in both systems development life cycle stages between.1.1 Enterprise ModelingDatabase development process from the enterprise modeling (system development life cycle stage of the project feasibility studies, and to choose a part)Organizations set the scope and general database content. Enterprise modeling in information systems planning and other activities, these activities determine which part of information systems need to change and strengthen the entire organization and outlines the scope of data. In this step, check the current database and information systems, development of the project as the main areas of the nature of the business, with a very general description of each term in the development of information systems when needed data. Each item only when it achieved the expected goals of organizations can be when the next step.1.2 Conceptual Data ModelingOne has already begun on the Information System project, the concept of data modeling phase of the information systems needs of all the data. It is divided into two stages. First, it began the project in the planning stage. At the same time outlining the establishment of other documents to the existing database without considering the circumstances specific development projects in the scope of the required data. This category only includes high-level data (entities), and main contact. Then in the system development life-cycle analysis stage must have a management information system set the entire organization Details of the data model definition of all data attributes, listing alldata types that all data inter-entity business linkages, defining description of the full data integrity rules. In the analysis phase, but also the concept of inspection data model (also called the concept behind the model) and the goal of information systems used to explain other aspects of the model of consistency categories, such as processing steps, rules and data processing time of timing. However, even if the concept is such detailed data model is only preliminary, because follow-up information system life cycle activities in the design of services, statements, display and inquiries may find that missing element or mistakes. Therefore, the concept of data often said that modeling is a top-down manner, its areas of operation from the general understanding of the driver, rather than the specific information processing activities by the driver.1.3 Logical Database DesignLogical database design from two perspectives database development. First, the concept of data model transform into relational database theory based on the criteria that means - between. Then, as the design of information systems, every computer procedures (including procedures for the input and output format), database support services, statements, and inquiries revealed that a detailed examination. In this so-called Bottom-up analysis, accurate verification of the need to maintain the database and the data in each affairs, statements and so on the needs of those in the nature of the data. For each separate statements, services, and so on the analysis must take into account a specific, limited but complete database view. When statements, services, and other analysis might be necessary to change the concept of data model. Especially in large-scale projects, the different analytical systems development staff and the team can work independently in different procedures or in a centralized, the details of their work until all the logic design stage may be displayed. In these circumstances, logic database design stage must be the original concept of data model and user view these independent or merged into a comprehensive design. In logic design information systems also identify additional information processing needs of these new demands at this time must be integrated into the logic of earlier identified in the database design.Logical database design is based on the final step for the formation of good data specifications and determine the rules, the combination, the data after consultation specifications orconverted into basic atomic element. Most of today's database, these rules from the relational database theory and the process known as standardization, #. This step is the result of management of these data have not cited any database management system for a complete description of the database map. Logical database design completed, we began to identify in detail the logic of the computer program and maintenance, the report contents of the database for inquiries.1.4 Physical database design and definitionPhysical database design and definition phase decisions computer memory (usually disk) database in the organization, definition of According to the library management system for physical structure, the procedures outlined processing services, produce the desired management information and decision support statements. The objective of this stage is to design an effective and safe management of all data-processing database, the physical database design to closely integrate the information systems of other physical aspects of the design, including procedures, computer hardware, operating systems and data communications networks.1.5 Database ImplementationThe database prepared by the realization stage, testing and installation procedures for handling databases. Designers can use the standard programming language (such as COBOL, C or Visual Basic), the dedicated database processing languages (such as SQL), or the process of the non-exclusive language programming in order to produce a statement of the fixed format, the result will be displayed, and may also include charts. In achieving stage, but also the completion of all the database files, training users for information systems (database) user setup program. The final step is to use existing sources of information (documents legacy applications and databases and now needs new data) loading data. Loading data is often the first step in data from existing files and databases to an intermediate format (such as binary or text files) and then to turn intermediate loading data to a new database. Finally, running databases and related applications for the actual user maintenance and retrieval of data. In operation, the regular backup database and the database when damaged or affected resume database. 1.6 Database maintenanceDuring the database in the progressive development of database maintenance. In this step, in order to meet changing business conditions, in order to correct the erroneous database design, database applications or processing speed increase, delete or change the structure of the database. When a procedure or failure of the computer database affect or damage the database may also be reconstruction. This step usually is the longest in the database development process step, as it continued to databases and related applications throughout the life cycle, the development of each database can be seen as a brief database development process and data modeling concepts arise, logical and physical database design and database to achieve dealing with the changes.two. Information System developed by other meansSystem Development Life Cycle minor changes in law or its variant of the often used to guide information systems and database development. Information System is a life-cycle methodology, it is highly structured approach, which includes many checks and balances to ensure that every step of produce accurate results, and new or alternative information system and it must communications or data definitions consistent existing system needs consistency. System development life cycle because of the regular need to have a working system for a long time been criticized because only work in the system until the end of the whole process generated. More and more organizations now use rapid application development method, it is a includes analysis, design and implementation of steps to repeat the rapid iterative process until convergence to users the system so far. Rapid Application Development Act required the database has been in existence, and enhance system is mainly to the application of data retrieval application, but not to those who generate and modify database applications.The most widely used method of rapid application development is one of the prototype. The prototype system is a method of iterative development process, analysts and users through close co-operation, continuing to revise the system will eventually convert all the needs of a working system. In this diagram we contains notes, briefly describes each stage of the prototype of the database development activities. Normally, when information systems problems were identified, tried only a rough concept of data modeling. In the development of the initial prototype, the design of the user wants todisplay and statements, and that any new database needs and define a term prototype database. This is usually a new database, copy the part of the existing system, but might also added some new content. When the need for new content, these elements are usually from external data sources, such as market research data, the general economic indicators or industry standards. When a prototype of a new version to repeat the achievement and maintenance of database activities. Usually only a minimum level of security and integrity control, because at this time the focus is as soon as possible to produce a prototype version can be used. But document management project also deferred to the final, only be used in the delivery of user training. Finally, once constructed an acceptable prototype, developers, and users will be the final decision of whether to prototype delivery and the use of the database. If the system (including database) efficiency is very low, then the system and database will be re-programming and re-organization in order to achieve the desired performance.Along with visual programming tools (such as Visual Basic, Java, Visual C + + and fourth generation language) increasingly popular use of visual programming tools can easily change the user interface with the system, the prototype is becoming the choice of system development methodology. Customers using the prototype method statements and show changes to the content and layout is quite easy. In the process, the new database needs were identified, so it is the development of the use of the existing database should be amended. There is even the possibility of a need for a new database system prototype method, in such circumstances, when the system demand in the iterative process of development in the ever-changing needs access to sample data, the construction or reconstruction of the database prototype.中文译文数据库开发过程基于信息工程的信息系统规划是数据库开发项目的一个来源。