网络在线游戏开发心得(服务器端、java)(Online game development experience (server side, Java))

网络在线游戏开发心得(服务器端、java)（Online game development experience (server side, Java)）Online game development experience (server side, Java).Txt, I would like to know, how many people separated, or still love?. His laugh to cry yourself to watch their own trouble. You use stealth to avoid me, I use stealth to help you! Until one day, in the hands of power, kill all the world, bear my dog. A multiplayer online chess game project is drawing to a close.I participated in the entire design flow of the project and completed the core code of 90%. There's a lot to be talked about about the project. This series is not going to be a very detailed specification of the project, which should be described in the design document, and I intend to say only a few points of note.One special thing about this project is that the client is a mobile phone and the user is communicating with the server over the mobile network. Compared with PC, the processing capacity of mobile phone is very weak, and the network traffic cost is expensive. Because in addition to considering some of the general online game problems, these two points also need to be fully considered in the design.First of all, the choice of language development, because the server is Linux environment, MS technology directly ruled out, as for MONO, well, I really do not worry. The alternative is C++ and Java, Java wins in the network formidable ability, the development cycle is short, has many frameworks and the open source storehouse support, writes the rotten unacceptable code is not easy; C++ wins in the speed. In all its aspects, C++ made it easier to turn this project into a bunch of code nightmares,and we chose Java.I. networkOnline games, the first problem facing, of course, is how to network communications. The first thing to consider is the HTTP protocol, because all the J2ME phones support this, and we certainly want to be as compatible as possible. Moreover, the HTTP protocol encapsulation is very high, without considering threads, synchronization, status management, connection pooling, but the HTTP protocol has two uncomfortable places:This protocol, this problem has plagued many people many times.I have considered the solution is to transform the HTTP protocol, socket does not close after the data transfer is complete, but the workload is very large, the project cycle, basically is the Mission impossible, will not be considered. The client can only request data from the server by polling.When the network traffic is too large. On this project, just passed between the network instruction, but each pass to add a useless HTTP Head, plus the client needs to do polling, the flow for mobile phone is simply a terrorist, by a simple test, calculated in accordance with the GPRS network costs 0.03 yuan /K, a game of cards that will consume 1 yuan fee (per second polling), is not acceptable. Maybe we can use the monthly rate fee method, but this topic has nothing to do with technology.The above problem led to our choice of Socket, which means we will not have a web environment, and many things will have to be implemented by ourselves: thread management, customerstatus monitoring, object pooling, console......... .The network part is intended to be implemented using Java NIO, which is a new network monitoring method, and asynchronous communication based on events can improve performance. After each client connection, there is a separate SocketChannel to communicate with it, and this SocketChannel will exist throughout the user's entire lifecycle. If the user disconnects, the server gets the -1 and throws the Connection reset exception. By capturing the two features, the relevant resources can be cleared up after the user accidentally disconnects. Because NIO is asynchronous communication, there is no complicated thread management.Two, communication protocolThe project does not have complex communication instructions, and the number of commands is limited, but there is a key issue that needs to be concerned about: traffic. To minimize traffic, we use bytes instead of strings to store system instructions, thus reducing traffic by half, such as using a byte to hold a card,The byte high indicates the color, and the byte is low for numbers. If the 0 represents spades, then the spade three should be 0x03, which requires bitwise operation:Int m=0;Int n=3;Byte card= (byte) (m) (<<4) | (byte) n; //m left four, then left with N or operationThe game needs to pass the user's integral, which is a large integer, uses four bytes to hold the comparison, and converts the integer to four bytes:Public, static, byte[], translateLong (long, mark){Byte[] B = new byte[4];For (int, I = 0, I, < 4, i++){B[i] = (byte) (mark > > > (24 - I * 8));}Return b;}The operation to turn four bytes back is as follows:Public, static, long, translateByte (byte[], b){Int mask = 0xff;Int temp = 0;Int res = 0;For (int, I = 0, I, < 4, i++){Res <<= 8;Temp = b[i] & mask;Res temp |=;}Return res;}Three database connection poolDue to the absence of a web environment, so we need our own implementation of a database connection pool, Apache has a project called Commons DBCP, which is based on a Apache object pool (APACHE commons pool) their database connection pool, we can be directly used to use, Apache Software may not be the best, but much better than we may write.Commons DBCP requires three.Jar:Commons-collections-3.1.jar, commons-dbcp-1.2.1.jar, commons-pool-1.2.jarThese three files can be downloaded under the Apache - Jakarta - commons project and added to the project.The code for constructing a database connection pool is as follows:Import java.sql.*;Import com.gwnet.games.antiLord.util.*;Import mons.dbcp.ConnectionFactory;Import mons.dbcp.BasicDataSource;Import mons.dbcp.DataSourceConnectionFactory;Private, static, BasicDataSource, bds=new, BasicDataSource ();Private static ConnectionFactory fac=null;/ / initialize the connection poolBds.setDriverClassName ("org.postgresql.Driver"); / / database driverBds.setUrl ("jdbc:postgresql://localhost:5432/myDB"); / / URL databaseBds.setUsername ("Postgres"); //dba accountBds.setPassword ("XXXXXXXX"); / / passwordBds.setInitialSize (100); / / initialize connection numberBds.setMaxIdle (10); / / the maximum number of idleBds.setMaxWait (1000*60); / / timeout recovery timeFac=new DataSourceConnectionFactory (BDS); / / get the connection factoryConnection (conn=fac.createConnection); / / get connection from the pool.(conn.close); / / release the connection back to the poolDestroy / connection poolBds.close ();Bds=null;Fac=null;Please handle all the exceptions in operation.Four, the formation of PokerThe need to generate random cards for users in the game, first we need to initialize a pack of cards in a Hashmap, each card represented by one byte, high representative colors, as the representative figures, generate the whole deck:Private, static, HashMap, cards = new, HashMap ();Int tmp=0;For (int = I = 0; I <4; i++) {For (int, M = 0, m, < 13, m++) {Tmp= ((byte) (I) (<<4) | (byte) m); / / use bit operation structure of a cardCards.放置（新整数（i * 13 + m），新字节（（字节）TMP））；}}卡。