java 试题练习题(第10套)
Java语言程序设计第10章习题参考答案
习题十参考答案10.1什么是进程？什么是线程？二者有什么联系和区别？进程是程序的一次动态执行过程，它对应了从代码加载、执行到执行完毕的一个完整过程，这个过程也是进程从产生、发展到消亡的过程。
线程是比进程更小的执行单位。
一个进程在其执行过程中，可以产生多个线程，形成多条执行线索。
每条线索，即每个线程也有它自身的产生、存在和消亡的过程，是一个动态的概念。
在进程运行过程中，每个进程都有一段专用的内存区域，并以PCB作为它存在的标志；与进程不同的是，线程间可以共享相同的内存单元(包括代码与数据)，并利用这些共享单位来实现数据交换、实时通信与必要的同步操作。
10.2线程有哪些基本状态？试描述它们的相互转换过程。
新建状态、就绪状态、运行状态、阻塞状态、死亡状态。
相互转换的过程如图：10.3创建线程的方式有哪几种？请举例说明。
1.继承自Thread类，代码逻辑写在子线程中，需要重写run()方法，主线程里start()就可以了。
public class ExtendsThread extends Thread{private final static int THREAD_NUM = 5;public static void main(String[] args){for (int i = 0; i <THREAD_NUM; i++) {new ExtendsThread("thread"+i).start();}}public ExtendsThread(String name){super(name);}@Overridepublic void run() {// TODO Auto-generated method stubfor (int i = 0; i < this.THREAD_NUM; i++) { System.out.println(this.getName()+i);}}}运行结果：thread00thread01thread02thread03thread04thread20thread21thread22thread23thread24thread40thread41thread42thread43thread44thread11thread12thread13thread14thread30thread31thread32thread33thread342.实现Runnable接口public class ImplRunnable implements Runnable {private static final int THREAD_NUM = 5;@Overridepublic void run() {for (int i = 0; i < THREAD_NUM; i++) {System.out.println(Thread.currentThread().getName()+i);}}public static void main(String[] args) {// TODO Auto-generated method stubfor (int j = 0; j < THREAD_NUM; j++) {ImplRunnable implRunnable= new ImplRunnable();new Thread(implRunnable,"thread"+j).start();}}}运行结果thread10thread12thread13thread14thread30thread31thread32thread33thread34thread00thread01thread02thread03thread04thread20thread21thread22thread23thread24thread40thread41thread42thread43thread4410.4试说明线程优先级及其调度的关系，并编写一个程序说明其关系。
java 试题练习题(第10套)
大学 —— 学年第 学期 《 Java 程序设计 》课程试题 课程号： √ 考试 □ A 卷 √ 闭卷 □ 考查 □ B 卷 □ 开卷一、单项选择题（20题；每题2分，共40分） 1、Java 语言具有许多的优点和特点，下列的选项＿＿＿反映了Java 程序并行机制的特点。
A ）安全性 B ）多线程 C ）跨平台 D ）可移植 答案： B 知识点： java 基础 难度系数C 2、下列关于JAVA 语言特点的叙述中,错误的是＿＿＿＿。
A ）Java 是面向过程的编程语言 B ）Java 支持分布式计算 C ）Java 是跨平台的编程语言 D ）Java 支持多线程 答案：A 知识点： java 基础 难度系数C 3、定义私有的成员函数或成员变量，正确的是＿＿＿＿。
A ）不需要定义，缺省的访问级就是私有级 B ）在类的开头部分集中定义 C ）成员函数需要定义，而成员变量不需要定义 D ）利用private 关键字定义答案： D 知识点： 类成员 难度系数C4、下列语句正确的是________。
A ）int a={1,2,3}B ）int b=(1,2,3);C ）int c[]={1,2,3}D ）int []d={1 2 3}（难度系数C ）答案：C 知识点：数组班级：姓名： 学号：试题共页加白纸张密封线5、在编写异常处理的Java程序中，每个catch语句块都应该与＿＿＿语句块对应，使得用该语句块来启动Java的异常处理机制。
A）if – else B）switch C）try D）throw（难度系数B）答案：C知识点：异常6、下列表述中，不正确的是＿＿＿。
A）标识符区分大小写B）改变变量的值不会改变其存储位置C）常量可以完全大写D）单精度变量赋值常数后面的字母“f”可以省略答案：D知识点：变量难度系数C7、下列陈述正确的是_________。
A）一个组件只能发生一种事件B）一个监听器处理一种事件C）多个事件监听器被注册到一个组件会引起编译错误D）如果多个事件监听器被注册到一个组件上，这些事件监听器一般都会起作用，但各个事件的处理顺序不确定（难度系数A）答案：D知识点：事件处理8、________属于容器的构件。
《Java语言程序设计(基础篇)》(第10版 梁勇 著)第九章练习题答案
《Java语言程序设计（基础篇）》（第10版梁勇著）第九章练习题答案9.1public class Exercise09_01 {public static void main(String[] args) {MyRectangle myRectangle = new MyRectangle(4, 40);System.out.println("The area of a rectangle with width " +myRectangle.width + " and height " +myRectangle.height + " is " +myRectangle.getArea());System.out.println("The perimeter of a rectangle is " +myRectangle.getPerimeter());MyRectangle yourRectangle = new MyRectangle(3.5, 35.9);System.out.println("The area of a rectangle with width " +yourRectangle.width + " and height " +yourRectangle.height + " is " +yourRectangle.getArea());System.out.println("The perimeter of a rectangle is " +yourRectangle.getPerimeter());}}class MyRectangle {// Data membersdouble width = 1, height = 1;// Constructorpublic MyRectangle() {}// Constructorpublic MyRectangle(double newWidth, double newHeight) {width = newWidth;height = newHeight;}public double getArea() {return width * height;}public double getPerimeter() {return 2 * (width + height);}}9.2public class Exercise09_02 {public static void main(String[] args) {Stock stock = new Stock("SUNW", "Sun MicroSystems Inc."); stock.setPreviousClosingPrice(100);// Set current pricestock.setCurrentPrice(90);// Display stock infoSystem.out.println("Previous Closing Price: " +stock.getPreviousClosingPrice());System.out.println("Current Price: " +stock.getCurrentPrice());System.out.println("Price Change: " +stock.getChangePercent() * 100 + "%");}}class Stock {String symbol;String name;double previousClosingPrice;double currentPrice;public Stock() {}public Stock(String newSymbol, String newName) {symbol = newSymbol;name = newName;}public double getChangePercent() {return (currentPrice - previousClosingPrice) /previousClosingPrice;}public double getPreviousClosingPrice() {return previousClosingPrice;}public double getCurrentPrice() {return currentPrice;}public void setCurrentPrice(double newCurrentPrice) {currentPrice = newCurrentPrice;}public void setPreviousClosingPrice(double newPreviousClosingPrice) { previousClosingPrice = newPreviousClosingPrice;}}9.3public class Exercise09_03 {public static void main(String[] args) {Date date = new Date();int count = 1;long time = 10000;while (count <= 8) {date.setTime(time);System.out.println(date.toString());count++;time *= 10;}}}9.4public class Exercise09_04 {public static void main(String[] args) {Random random = new Random(1000);for (int i = 0; i < 50; i++)System.out.print(random.nextInt(100) + " ");}9.5public class Exercise09_05 {public static void main(String[] args) {GregorianCalendar calendar = new GregorianCalendar();System.out.println("Year is " + calendar.get(GregorianCalendar.YEAR)); System.out.println("Month is " + calendar.get(GregorianCalendar.MONTH)); System.out.println("Date is " + calendar.get(GregorianCalendar.DATE));calendar.setTimeInMillis(1234567898765L);System.out.println("Year is " + calendar.get(GregorianCalendar.YEAR)); System.out.println("Month is " + calendar.get(GregorianCalendar.MONTH)); System.out.println("Date is " + calendar.get(GregorianCalendar.DATE)); }}9.6public class Exercise09_06 {static String output = "";/** Main method */public static void main(String[] args) {Scanner input = new Scanner(System.in);// Prompt the user to enter yearSystem.out.print("Enter full year (i.e. 2001): ");int year = input.nextInt();// Prompt the user to enter monthSystem.out.print("Enter month in number between 1 and 12: ");int month = input.nextInt();// Print calendar for the month of the yearprintMonth(year, month);System.out.println(output);}/** Print the calendar for a month in a year */static void printMonth(int year, int month) {// Get start day of the week for the first date in the monthint startDay = getStartDay(year, month);// Get number of days in the monthint numOfDaysInMonth = getNumOfDaysInMonth(year, month);// Print headingsprintMonthTitle(year, month);// Print bodyprintMonthBody(startDay, numOfDaysInMonth);}/** Get the start day of the first day in a month */static int getStartDay(int year, int month) {// Get total number of days since 1/1/1800int startDay1800 = 3;long totalNumOfDays = getTotalNumOfDays(year, month);// Return the start dayreturn (int)((totalNumOfDays + startDay1800) % 7);}/** Get the total number of days since Jan 1, 1800 */static long getTotalNumOfDays(int year, int month) {long total = 0;// Get the total days from 1800 to year -1for (int i = 1800; i < year; i++)if (isLeapYear(i))total = total + 366;elsetotal = total + 365;// Add days from Jan to the month prior to the calendar month for (int i = 1; i < month; i++)total = total + getNumOfDaysInMonth(year, i);return total;}/** Get the number of days in a month */static int getNumOfDaysInMonth(int year, int month) {if (month == 1 || month==3 || month == 5 || month == 7 ||month == 8 || month == 10 || month == 12)return 31;if (month == 4 || month == 6 || month == 9 || month == 11)return 30;if (month == 2)if (isLeapYear(year))return 29;elsereturn 28;return 0; // If month is incorrect.}/** Determine if it is a leap year */static boolean isLeapYear(int year) {if ((year % 400 == 0) || ((year % 4 == 0) && (year % 100 != 0))) return true;return false;}/** Print month body */static void printMonthBody(int startDay, int numOfDaysInMonth) { // Pad space before the first day of the monthint i = 0;for (i = 0; i < startDay; i++)output += " ";for (i = 1; i <= numOfDaysInMonth; i++) {if (i < 10)output += " " + i;elseoutput += " " + i;if ((i + startDay) % 7 == 0)output += "\n";}output += "\n";}/** Print the month title, i.e. May, 1999 */static void printMonthTitle(int year, int month) {output += " " + getMonthName(month)+ ", " + year + "\n";output += "-----------------------------\n";output += " Sun Mon Tue Wed Thu Fri Sat\n";}/** Get the English name for the month */static String getMonthName(int month) {String monthName = null;switch (month) {case 1: monthName = "January"; break;case 2: monthName = "February"; break;case 3: monthName = "March"; break;case 4: monthName = "April"; break;case 5: monthName = "May"; break;case 6: monthName = "June"; break;case 7: monthName = "July"; break;case 8: monthName = "August"; break;case 9: monthName = "September"; break;case 10: monthName = "October"; break;case 11: monthName = "November"; break;case 12: monthName = "December";}return monthName;}}9.7public class Exercise09_07 {public static void main (String[] args) {Account account = new Account(1122, 20000);Account.setAnnualInterestRate(4.5);account.withdraw(2500);account.deposit(3000);System.out.println("Balance is " + account.getBalance()); System.out.println("Monthly interest is " +account.getMonthlyInterest());System.out.println("This account was created at " +account.getDateCreated());}}class Account {private int id;private double balance;private static double annualInterestRate;private java.util.Date dateCreated;public Account() {dateCreated = new java.util.Date();}public Account(int newId, double newBalance) {id = newId;balance = newBalance;dateCreated = new java.util.Date();}public int getId() {return this.id;}public double getBalance() {return balance;}public static double getAnnualInterestRate() {return annualInterestRate;}public void setId(int newId) {id = newId;}public void setBalance(double newBalance) {balance = newBalance;}public static void setAnnualInterestRate(double newAnnualInterestRate) { annualInterestRate = newAnnualInterestRate;}public double getMonthlyInterest() {return balance * (annualInterestRate / 1200);}public java.util.Date getDateCreated() { return dateCreated;}public void withdraw(double amount) {balance -= amount;}public void deposit(double amount) {balance += amount;}}9.8public class Exercise09_08 {public static void main(String[] args) { Fan1 fan1 = new Fan1();fan1.setSpeed(Fan1.FAST);fan1.setRadius(10);fan1.setColor("yellow");fan1.setOn(true);System.out.println(fan1.toString());Fan1 fan2 = new Fan1();fan2.setSpeed(Fan1.MEDIUM);fan2.setRadius(5);fan2.setColor("blue");fan2.setOn(false);System.out.println(fan2.toString()); }}class Fan1 {public static int SLOW = 1;public static int MEDIUM = 2;public static int FAST = 3;private int speed = SLOW;private boolean on = false;private double radius = 5;private String color = "white";public Fan1() {}public int getSpeed() {return speed;}public void setSpeed(int newSpeed) {speed = newSpeed;}public boolean isOn() {return on;}public void setOn(boolean trueOrFalse) {this.on = trueOrFalse;}public double getRadius() {return radius;}public void setRadius(double newRadius) { radius = newRadius;}public String getColor() {return color;}public void setColor(String newColor) {color = newColor;}@Overridepublic String toString() {return"speed " + speed + "\n"+ "color " + color + "\n"+ "radius " + radius + "\n"+ ((on) ? "fan is on" : " fan is off"); }}public class Exercise09_09 {public static void main(String[] args) {RegularPolygon polygon1 = new RegularPolygon();RegularPolygon polygon2 = new RegularPolygon(6, 4);RegularPolygon polygon3 = new RegularPolygon(10, 4, 5.6, 7.8);System.out.println("Polygon 1 perimeter: " +polygon1.getPerimeter());System.out.println("Polygon 1 area: " + polygon1.getArea());System.out.println("Polygon 2 perimeter: " +polygon2.getPerimeter());System.out.println("Polygon 2 area: " + polygon2.getArea());System.out.println("Polygon 3 perimeter: " +polygon3.getPerimeter());System.out.println("Polygon 3 area: " + polygon3.getArea());}}class RegularPolygon {private int n = 3;private double side = 1;private double x;private double y;public RegularPolygon() {}public RegularPolygon(int number, double newSide) {n = number;side = newSide;}public RegularPolygon(int number, double newSide, double newX, double newY) {n = number;side = newSide;x = newX;y = newY;}public int getN() {return n;}public void setN(int number) {n = number;}public double getSide() {return side;}public void setSide(double newSide) {side = newSide;}public double getX() {return x;}public void setX(double newX) {x = newX;}public double getY() {return y;}public void setY(double newY) {y = newY;}public double getPerimeter() {return n * side;}public double getArea() {return n * side * side / (Math.tan(Math.PI / n) * 4); }}9.10public class Exercise09_10 {public static void main(String[] args) {Scanner input = new Scanner(System.in);System.out.print("Enter a, b, c: ");double a = input.nextDouble();double b = input.nextDouble();double c = input.nextDouble();QuadraticEquation equation = new QuadraticEquation(a, b, c);double discriminant = equation.getDiscriminant();if (discriminant < 0) {System.out.println("The equation has no roots");}else if (discriminant == 0){System.out.println("The root is " + equation.getRoot1());}else// (discriminant >= 0){System.out.println("The roots are " + equation.getRoot1()+ " and " + equation.getRoot2());}}}class QuadraticEquation {private double a;private double b;private double c;public QuadraticEquation(double newA, double newB, double newC) {a = newA;b = newB;c = newC;}double getA() {return a;}double getB() {return b;}double getC() {return c;}double getDiscriminant() {return b * b - 4 * a * c;}double getRoot1() {if (getDiscriminant() < 0)return 0;else {return (-b + getDiscriminant()) / (2 * a);}}double getRoot2() {if (getDiscriminant() < 0)return 0;else {return (-b - getDiscriminant()) / (2 * a);}}}9.11public class Exercise09_11 {public static void main(String[] args) {Scanner input = new Scanner(System.in);System.out.print("Enter a, b, c, d, e, f: ");double a = input.nextDouble();double b = input.nextDouble();double c = input.nextDouble();double d = input.nextDouble();double e = input.nextDouble();double f = input.nextDouble();LinearEquation equation = new LinearEquation(a, b, c, d, e, f);if (equation.isSolvable()) {System.out.println("x is " +equation.getX() + " and y is " + equation.getY());}else {System.out.println("The equation has no solution");}}}class LinearEquation {private double a;private double b;private double c;private double d;private double e;private double f;public LinearEquation(double newA, double newB, double newC, double newD, double newE, double newF) {a = newA;b = newB;c = newC;d = newD;e = newE;f = newF;}double getA() {return a;}double getB() {return b;}double getC() {return c;}double getD() {return d;}double getE() {return e;}double getF() {return f;}boolean isSolvable() {return a * d - b * c != 0;}double getX() {double x = (e * d - b * f) / (a * d - b * c);return x;}double getY() {double y = (a * f - e * c) / (a * d - b * c);return y;}}9.12public class Exercise09_12 {public static void main(String[] args) {Scanner input = new Scanner(System.in);System.out.print("Enter the endpoints of the first line segment: ");double x1 = input.nextDouble();double y1 = input.nextDouble();double x2 = input.nextDouble();double y2 = input.nextDouble();System.out.print("Enter the endpoints of the second line segment: ");double x3 = input.nextDouble();double y3 = input.nextDouble();double x4 = input.nextDouble();double y4 = input.nextDouble();// Build a 2 by 2 linear equationdouble a = (y1 - y2);double b = (-x1 + x2);double c = (y3 - y4);double d = (-x3 + x4);double e = -y1 * (x1 - x2) + (y1 - y2) * x1;double f = -y3 * (x3 - x4) + (y3 - y4) * x3;LinearEquation equation = new LinearEquation(a, b, c, d, e, f);if (equation.isSolvable()) {System.out.println("The intersecting point is: (" +equation.getX() + ", " + equation.getY() + ")");}else {System.out.println("The two lines do not cross ");}}}9.13public class Exercise09_13 {public static void main(String[] args) {Scanner input = new Scanner(System.in);System.out.print("Enter the number of rows and columns of the array: ");int numberOfRows = input.nextInt();int numberOfColumns = input.nextInt();double[][] a = new double[numberOfRows][numberOfColumns];System.out.println("Enter the array: ");for (int i = 0; i < a.length; i++)for (int j = 0; j < a[i].length; j++)a[i][j] = input.nextDouble();Location location = locateLargest(a);System.out.println("The location of the largest element is " + location.maxValue + " at ("+ location.row + ", " + location.column + ")");}public static Location locateLargest(double[][] a) {Location location = new Location();location.maxValue = a[0][0];for (int i = 0; i < a.length; i++)for (int j = 0; j < a[i].length; j++) {if (location.maxValue < a[i][j]) {location.maxValue = a[i][j];location.row = i;location.column = j;}}return location;}}class Location {int row, column;double maxValue;}9.14public class Exercise09_14 {public static void main(String[] args) {int size = 100000;double[] list = new double[size];for (int i = 0; i < list.length; i++) {list[i] = Math.random() * list.length;}StopWatch stopWatch = new StopWatch();selectionSort(list);stopWatch.stop();System.out.println("The sort time is " + stopWatch.getElapsedTime()); }/** The method for sorting the numbers */public static void selectionSort(double[] list) {for (int i = 0; i < list.length - 1; i++) {// Find the minimum in the list[i..list.length-1]double currentMin = list[i];int currentMinIndex = i;for (int j = i + 1; j < list.length; j++) {if (currentMin > list[j]) {currentMin = list[j];currentMinIndex = j;}}// Swap list[i] with list[currentMinIndex] if necessary;if (currentMinIndex != i) {list[currentMinIndex] = list[i];list[i] = currentMin;}}}}class StopWatch {private long startTime = System.currentTimeMillis(); private long endTime = startTime;public StopWatch() {}public void start() {startTime = System.currentTimeMillis();}public void stop() {endTime = System.currentTimeMillis();}public long getElapsedTime() {return endTime - startTime;}}。
【免费下载】java 试题练习题(第10套)
3、定义私有的成员函数或成员变量，正确的是＿＿＿＿。
A）不需要定义，缺省的访问级就是私有级 B）在类的开头部分集中定义
C）成员函数需要定义，而成员变量不需要定义 D）利用private 关键字定
答案： D 知识点： 类成员
4、下列语句正确的是________。
A）int a={1,2,3}
C）int c[]={1,2,3}
(难度系数 A，重载) D
18、String s1 = new String(“Hello”);
String s2 = new String(“there”);
String s3 = new String();
D）static 方法中能处理非 static 的
知识点：关键字
上面是 Java 程序中的一些声明，选项中能通过编译的是______。
机制的特点。
义
A）安全性 B）多线程 C）跨平台 D）可移植
答案： B 知识点： java基础
2、下列关于 JAVA 语言特点的叙述中,错误的是＿＿＿＿。
A）Java 是面向过程的编程语言 B）Java 支持分布式计算
C）Java 是跨平台的编程语言 D）Java 支持多线程
答案：A 知识点： java 基础
用，但各个事件的处理顺序不确定
（难度系数 A）答案：D 知识点：事件处理
8、________属于容器的构件。
A）JFrame B）JButton
C）JPnel
D）JApplet
答案：A；难度：C；知识点：窗体与控件。
9、如果希望所有的控件在界面上均匀排列，应使用_____布局管理器。
A）BoxLayout B）GridLayout
Java语言程序设计（基础篇）第10版习题答案Chapter9-1
Java语⾔程序设计（基础篇）第10版习题答案Chapter9-1（矩形类 Rectangle）遵照9.2节中 Circle 类的例⼦，设计⼀个名为 Rectangle 的类表⽰矩形。
这个类包括：两个名为 width 和 height 的 double 型数据域，它们分别表⽰矩形的宽和⾼。
width 和 height 的默认值都为1。
创建默认矩形的⽆参构造⽅法⼀个创建 width 和 height 为指定值的矩形的构造⽅法。
⼀个名为 getArea() 的⽅法返回这个矩形的⾯积。
⼀个名为 getPerimeter() 的⽅法返回周长。
画出该矩形的 UML 图并实现这个类。
编写⼀个测试程序，创建两个 Rectangle 对象——⼀个矩形的宽为 4 ⽽⾼为 40，另⼀个矩形的宽为3.5 ⽽⾼为 35.9 。
按照这个顺序显⽰每个矩形的宽、⾼、⾯积、周长。
程序代码：public class Rectangle {private double width;private double height;public Rectangle(){width=1.0;height=1.0;}public Rectangle(double width,double height) {this.width=width;this.height=height;}public double getWidth() {return width;}public double getHeight() {return height;}public double getArea() {return width*height;}public double getPerimeter() {return 2*(width+height);}public static void main(String[] args) {// TODO Auto-generated method stubRectangle t1=new Rectangle(4,40);Rectangle t2=new Rectangle(3.5,35.9);System.out.println("width:"+t1.getWidth()+" height:"+t1.getHeight()+" Area:"+t1.getArea()+" Per:"+t1.getPerimeter());System.out.println("width:"+t2.getWidth()+" height:"+t2.getHeight()+" Area:"+t2.getArea()+" Per:"+t2.getPerimeter());}}运⾏结果：width:4.0 height:40.0 Area:160.0 Per:88.0width:3.5 height:35.9 Area:125.64999999999999 Per:78.8。
java语言程序设计基础篇第十版练习答案精编
j a v a语言程序设计基础篇第十版练习答案精编Document number：WTT-LKK-GBB-08921-EIGG-2298601import class Exercise14_01 extendsApplication {@Override Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}02import class Exercise14_02 extends Application {@Override Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}03import class Exercise14_03 extends Application {@Override One is to use the hint in the book.ArrayList<Integer> list = new ArrayList<>(); for (int i = 1; i <= 52; i++) {(i);}HBox pane = new HBox(5);;().add(new ImageView("image/card/" + (0) +".png"));().add(new ImageView("image/card/" + (1) +".png"));().add(new ImageView("image/card/" + (2) +".png"));Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}04import class Exercise14_04 extends Application {@Override dd(txt);}Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}05import class Exercise14_05 extends Application {@Override dd(txt);}Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}05import class Exercise14_05 extends Application {@Override dd(txt);}Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}06import class Exercise14_06 extends Application {@Override dd(rectangle);}}Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}07import class Exercise14_07 extends Application {@Override Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}08import class Exercise14_08 extends Application {@Override ng"), j, i);}}Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}09import class Exercise14_09 extends Application {@Override Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}class FanPane extends Pane {double radius = 50;public FanPane() {Circle circle = new Circle(60, 60, radius);;;getChildren().add(circle);Arc arc1 = new Arc(60, 60, 40, 40, 30, 35);; ddAll(arc1, arc2, arc3, arc4);}}10import class Exercise14_10 extends Application {@Override ddAll, ;Arc arc2 = new Arc(100, 140, 50, 20, 180, 180); ;;().addAll(ellipse, arc1, arc2,new Line(50, 40, 50, 140), new Line(150, 40, 150, 140));Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}11import class Exercise14_11 extends Application {@Override ddAll(circle, ellipse1, ellipse2,circle1, circle2, line1, line2, line3, arc);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}12import class Exercise14_12 extends Application {@Override ddAll(r1, text1, r2, text2, r3, text3, r4, text4);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}13import class Exercise14_13 extends Application {@Override ddAll(arc1, text1, arc2, text2, arc3, text3, arc4, text4);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}14import class Exercise14_14 extends Application {@Override ddAll(r1, r2, line1, line2, line3, line4);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}15import class Exercise14_15 extends Application {@Override ddAll(polygon, text);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}16import class Exercise14_16 extends Application {@Override ind().divide(3));().bind());().bind().divide(3));;Line line2 = new Line(0, 0, 0, 0);().bind().multiply(2).divide(3));().bind());().bind().multiply(2).divide(3));;Line line3 = new Line(0, 0, 0, 0);().bind().divide(3));().bind().divide(3));().bind());;Line line4 = new Line(0, 0, 0, 0);().bind().multiply(2).divide(3));().bind().multiply(2).divide(3));().bind());;().addAll(line1, line2, line3, line4);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}17import class Exercise14_17 extends Application {@Override ddAll(arc, line1, line2, line3, circle, line4, line5, line6, line7, line8);Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}18import class Exercise14_18 extends Application {@Override ddAll(polyline, line1, line2,line3, line4, line5, line6, text1, text2);Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}19import class Exercise14_19 extends Application {@Override ddAll(polyline1, polyline2, line1,line2,line3, line4, line5, line6, text1, text2,text3,text4, text5, text6, text7);Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}20import class Exercise14_20 extends Application {@Override dd(new Line(x1, y1, x2, y2));dd(new Line(x2, y2, (x2 + (arctan + set45) * arrlen)),((y2)) + (arctan + set45) * arrlen)));().add(new Line(x2, y2, (x2 + (arctan - set45) * arrlen)),((y2)) + (arctan - set45) * arrlen)));}/*** The main method is only needed for the IDE with limited* JavaFX support. Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}21import class Exercise14_21 extends Application {@Override istance(x2, y2) + "");().addAll(circle1, circle2, line, text);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}22import class Exercise14_22 extends Application {@Override ddAll(circle1, circle2, line, text1, text2);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}23import class Exercise14_23 extends Application {@Override ddAll(r1, r2, text);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}24import class Exercise14_24 extends Application {@Override ddAll(polygon, new Circle(x5, y5, 10), text);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}25import class Exercise14_25 extends Application {@Override ddAll(circle, polygon);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}26import class Exercise14_26 extends Application {@Override ddAll(clock1, clock2);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}27import class Exercise14_27 extends Application {@OverrideNot needed for running from the command line. */public static void main(String[] args) {launch(args);}}class DetailedClockPane extends Pane {private int hour;private int minute;private int second;lear();getChildren().addAll(circle, sLine, mLine, hLine);dd(new Line(xOuter, yOuter, xInner, yInner));}dd(text);}}}28import class Exercise14_28 extends Application {@OverrideNot needed for running from the command line.*/public static void main(String[] args) {launch(args);}}class ClockPaneWithBooleanProperties extends Pane { private int hour;private int minute;private int second;private boolean hourHandVisible = true;private boolean minuteHandVisible = true; private boolean secondHandVisible = true;public boolean isHourHandVisible() {return hourHandVisible;}public void setHourHandVisible(boolean hourHandVisible) {= hourHandVisible;paintClock();}public boolean isMinuteHandVisible() {return minuteHandVisible;}public void setMinuteHandVisible(boolean minuteHandVisible) {= minuteHandVisible;paintClock();}public boolean isSecondHandVisible() {return secondHandVisible;public void setSecondHandVisible(boolean secondHandVisible) {= secondHandVisible;paintClock();}lear();getChildren().addAll(circle, t1, t2, t3, t4);if (secondHandVisible) {getChildren().add(sLine);}if (minuteHandVisible) {getChildren().add(mLine);}if (hourHandVisible) {getChildren().add(hLine);}}}import class Exercise14_29 extends Application {final static double HGAP = 20;final static double VGAP = 20;final static double RADIUS = 5;final static double LENGTH_OF_SLOTS = 40;final static double LENGTH_OF_OPENNING = 15;final static double Y_FOR_FIRST_NAIL = 50;final static double NUMBER_OF_SLOTS = 9;final static double NUMBER_OF_ROWS =NUMBER_OF_SLOTS - 2;@Override dd(c);}}dd(new Line(x, y, x, y + LENGTH_OF_SLOTS)); }dd(new Line(centerX - (NUMBER_OF_ROWS - 1) * HGAP / 2 - HGAP,y + LENGTH_OF_SLOTS, centerX -(NUMBER_OF_ROWS - 1) * HGAP / 2 + NUMBER_OF_ROWS * HGAP,y + LENGTH_OF_SLOTS));dd(new Line(centerX + HGAP / 2,Y_FOR_FIRST_NAIL + RADIUS,centerX - (NUMBER_OF_ROWS - 1) * HGAP / 2 + NUMBER_OF_ROWS * HGAP, y));().add(new Line(centerX - HGAP / 2,Y_FOR_FIRST_NAIL + RADIUS,centerX - (NUMBER_OF_ROWS - 1) * HGAP / 2 - HGAP, y));dd(new Line(centerX - HGAP / 2,Y_FOR_FIRST_NAIL + RADIUS,centerX - HGAP / 2, Y_FOR_FIRST_NAIL - LENGTH_OF_OPENNING));().add(new Line(centerX + HGAP / 2,Y_FOR_FIRST_NAIL + RADIUS,centerX + HGAP / 2, Y_FOR_FIRST_NAIL - LENGTH_OF_OPENNING));Not needed for running from the command line.*/public static void main(String[] args) { launch(args);}}。
10级Java 试卷A
else if (s.substring(0,3).equals("abc")){
System.out.println(s.substring(3));
}
else {
System.out.println(s);
}
}
in.close();
}catch(FileNotFoundException e) {
1.以下程序的输出结果为＿＿＿＿＿。（5分）
public class mysort
{ public static void main(String args[ ]){
int i, j, k, temp;
int x[]= {1,5,3,4,2,7};
for( i= 0; i<x.length-1; i++ ) {
A. ResultsetB. ResultSet
C. ResultD.以上都不是
13.启动一个线程的方法是()。
A. run()B. start()
C. new()D. await()
14.加载某个数据库驱动程序的JDBC语句是()。
A.Class.forName()
B.DriverManager.getDrivers()
10.定义一个接口时，可以用以下哪个修饰符修饰成员？()。
A.publicB.protectedC.privateD.private或public
11.程序demo.java代码如下，其中正确的是()。
public person {}
class student extends person {}
public class demo {
（）8.若一个类实现了某个接口，则一定实现了其超接口。
Java语言程序设计(基础篇)(第10版 梁勇著)第一章练习题答案
System.out.println("people of thirdYear = " + thirdYear); System.out.println("people of fourthYear = " + fourthYear); System.out.println("people of fifthYear = " + fifthYear); } }
// 第一章 P26 编程练习题1.1和1.2 （显示三条消息/显示五条消息） public class WelcomeWithThreeMessages { public static void main(String[] args) { System.out.println("Welcome to Java"); System.out.println("Welcome to Computer Science"); System.out.println("Programming is fun"); System.out.println("Welcome System.out.println("Welcome System.out.println("Welcome System.out.println("Welcome System.out.println("Welcome } } to to to to to Java"); Java"); Java"); Java"); Java");
// 第一章 P27 练习题1.10 （以英里计的平均速度） public class AverageSpeed { public static void main(String[] args) { // 45.5分钟等于45分钟30秒 double speedkm = 60 / (45.5 / 14); double speedm = speedkm / 1.6; // m/h代表英里/每小时 System.out.println("averagespeed = " + speedm + "m/h");
AnjoyoJava10课后习题带答案
AnjoyoJava10课后习题带答案以下是为大家整理的AnjoyoJava10课后习题带答案的相关范文，本文关键词为AnjoyoJava10,课后,习题,答案,AnjoyoJa，您可以从右上方搜索框检索更多相关文章，如果您觉得有用，请继续关注我们并推荐给您的好友，您可以在综合文库中查看更多范文。
AnjoyoJava10课后习题一、选择题：1.下列哪一个是计算机的联网不可以实现的功能（）。
A、使用远程资源b、共享信息、程序和数据c、分布处理D、共享硬件2.下列哪个不属于计算机网络按照网络拓扑结构可以分为（）的网络类型。
A、星型网络b、光导纤维c、总线网络D、环线网络3.下列关于网络工作模式说法不正确的是（）A、专用服务器结构，由若干台微机工作站与一台或多台文件服务器通过通信线路连接起来组成工作站存取服务器文件。
b、客户机/服务器模式，这种典型的用法是银行pos机。
c、客户机/服务器模式，其中一台或几台较大的计算机集中进行共享数据库的管理和存取，称为服务器。
D、对等式网络中没有专用服务器，每一个工作站既可以起客户机作用也可以起服务器作用。
4.下列关于osI参考模型的说法不正确的是（）A、数据链路层是最底层，它是网络硬件设备之间的接口。
b、网络层通过网络连接交换网络服务数据单元。
c、会话层提供两个进程间的连接管理功能。
D、应用层是直接面对用户的一层，提供osI用户服务。
5.下列关于Tcp协议说法错误的是（）A、Tcp协议它为两台计算机之间的连接起了重要作用。
b、Tcp协议会让它们建立一个连接、发送和接收数据以及终止连接。
c、Tcp协议被称作一种不可靠的端对端协议。
D、Tcp重发一切没有收到的数据，进行数据内容准确性检查并保证分组的正确顺序。
6.下列关于Ip协议说法错误的是（）。
A、Internet上的所有数据通过Ip包的方式传输。
b、如果希望能在Internet上进行交流和通信，每台连上Internet的计算机都必须遵守Ip协议。
Java语言程序设计(基础篇)(第10版 梁勇著)第二章练习题答案
《Java语言程序设计（基础篇）》（第10版 梁勇 著） 第二章 基本程序设计 练习题答案
本人在自学编程过程中，发现本书答案很难找，找到的要么不完整、要么错误百出，所以我将自己所做的 练习题答案，提供给有需要者，供大家交流。本章答案均为本人一字一字所敲，答案均经过验证，虽为初学者， 但代码均按照书中规范要求书写，如有错误或更好的建议，请指正交流。
// 第二章 P59 练习题2.1 （将摄氏温度转为华氏温度） import java.util.Scanner;
public class CelsiusToFahrenheit {
public static void main(String[] args) { // 华氏温度和摄氏温度的转换公式为：华氏温度 = (9/5)*摄氏温度+32 Scanner input = new Scanner(System.in);
System.out.print("Enter the time zone offset to GMT: "); long timeZoneOffset = input.nextLong(); // 此处用long还是int？
long totalMilliseconds = System.currentTimeMillis(); long totalSeconds = totalMilliseconds / 1000; long currentSecond = totalSeconds % 60; long totalMinutes = totalSeconds / 60; long currentMinute = totalMinutes % 60; long totalHours = totalMinutes / 60; long currentHour = totalHours % 24; long hour = currentHour + timeZoneOffset;
《Java语言程序设计(基础篇)》(第10版 梁勇 著)第二十一章练习题答案
《Java语言程序设计（基础篇）》（第10版梁勇著）第二十一章练习题答案21.1import java.util.*;public class Exercise21_01 {public static void main(String[] args) {LinkedHashSet<String> set1 = new LinkedHashSet<String>(Arrays.asList( new String[]{"George", "Jim", "John", "Blake", "Kevin", "Michael"}));LinkedHashSet<String> set1Clone1 = (LinkedHashSet<String>)set1.clone(); LinkedHashSet<String> set1Clone2 = (LinkedHashSet<String>)set1.clone();LinkedHashSet<String> set2 = new LinkedHashSet<String>(Arrays.asList( new String[] {"George", "Katie", "Kevin", "Michelle", "Ryan"}));set1.addAll(set2);set1Clone1.removeAll(set2);set1Clone2.retainAll(set2);System.out.println("The union of the two sets is " + set1);System.out.println("The difference of the two sets is " + set1Clone1); System.out.println("The intersection of the two sets is " + set1Clone2); }}21.1附加import java.util.*;public class Exercise21_01Extra {public static void main(String[] args) {System.out.print("Enter a string: ");Scanner input = new Scanner(System.in);String s = input.nextLine();Character[] list1 = {'A', 'E', 'I', 'O', 'U'};Set<Character> vowels = new HashSet<>(Arrays.asList(list1));Set<Character> vowelsInString = new HashSet<>();Set<Character> consonantsInString = new HashSet<>();int numbeOfVowels = 0;int numbeOfConsonants = 0;for (int i = 0; i < s.length(); i++) {char ch = Character.toUpperCase(s.charAt(i));if (Character.isLetter(ch)) {if (vowels.contains(ch)) {if (!vowelsInString.contains(ch)) {vowelsInString.add(ch);numbeOfVowels++;}}else if (!consonantsInString.contains(ch)) {consonantsInString.add(ch);numbeOfConsonants++;}}}System.out.println("The number of vowels is " + numbeOfVowels);System.out.println("The number of consonants is " + numbeOfConsonants); }}21.2import java.util.*;import java.io.*;public class Exercise21_02 {public static void main(String[] args) {if (args.length != 1) {System.out.println("Usage: java Exercise21_02 fullfilename");System.exit(1);}String filename = args[0];// Create a tree set to hold the wordsTreeSet<String> treeSet = new TreeSet<String>();try {Scanner in = new Scanner(new File(filename));String line;while ((line = in.nextLine()) != null) {String[] tokens = line.split("[ |\n|\t|\r|.|,|)|(|-|\"]");for (int i = 0; i < tokens.length; i++)treeSet.add(tokens[i]);}}catch (Exception ex) {System.err.println(ex);}// Get an iterator for the setIterator iterator = treeSet.iterator();// Display mappingsSystem.out.println("\nDisplay words in ascending order ");while (iterator.hasNext()) {System.out.println(iterator.next());}}}21.3import java.util.*;import java.io.*;public class Exercise21_03 {public static void main(String[] args) {// Check usageif (args.length != 1) {System.out.println("Usage: java Exercise21_03 file.java");System.exit(1);}// Array of all Java keywords + true + nullString[] keywordString = {"abstract", "finally", "public", "boolean", "float", "return", "break", "for", "short", "byte","goto", "static", "case", "if", "super", "catch", "implements", "switch", "char", "import", "synchronized", "class","instanceof", "this", "const", "int", "throw", "continue","interface", "throws", "default", "long", "transient", "do","native", "try", "double", "new", "void", "else", "package","volatile", "extends", "private", "while", "final","protected", "true", "null"};Set<String> keywordSet =new HashSet<String>(Arrays.asList(keywordString));int count = 0;try {Scanner input = new Scanner(new File(args[0]));String text = "";while (input.hasNext()) {String line = input.nextLine();line = stripLineComments(line);line = stripLineStringLiterals(line);text += line + " ";}text = stripParagraghComments(text);String[] tokens = text.split("[ \\[,()\\]]");for (String token: tokens) {if (keywordSet.contains(token))count++;}System.out.println("The number of keywords in the program is " + count);}catch (Exception ex) {ex.printStackTrace();}}/* Strip line comments */private static String stripLineComments(String line) {int index = line.indexOf("//");if (index < 0)return line;elsereturn line.substring(0, index);}/* Strip string literals */private static String stripLineStringLiterals(String line) {int start = line.indexOf("\"");int end = line.indexOf("\"", start + 1);while (start > 0 && end > 0) {line = line.substring(0, start) + line.substring(end + 1);start = line.indexOf("\"");end = line.indexOf("\"");}return line;}/* Strip paragraph comments */private static String stripParagraghComments(String text) {int start = text.indexOf("/*");int end = text.indexOf("*/");while (start > 0 && end > 0) {text = text.substring(0, start) + text.substring(end + 2);start = text.indexOf("/*");end = text.indexOf("*/");}return text;}}/** This is an incorrect version. It does not count the case such as (this. Here the this keyword* is not counted. It does not exclude keywords in the comments*import java.util.*;import java.io.*;public class Exercise20_03 {public static void main(String[] args) {// Check usageif (args.length != 1) {System.out.println("Usage: java Exercise20_03 file.java");System.exit(0);}// Array of all Java keywords + true + nullString[] keywordString = {"abstract", "finally", "public","boolean", "float", "return", "break", "for", "short", "byte", "goto", "static", "case", "if", "super", "catch", "implements", "switch", "char", "import", "synchronized", "class","instanceof", "this", "const", "int", "throw", "continue","interface", "throws", "default", "long", "transient", "do","native", "try", "double", "new", "void", "else", "package","volatile", "extends", "private", "while", "final","protected", "true", "null"};Set<String> keywordSet =new HashSet<String>(Arrays.asList(keywordString));int count = 0;try {Scanner input = new Scanner(new File(args[0]));while (input.hasNext()) {String token = input.next();if (keywordSet.contains(token))count++;}System.out.println("The number of keywords in the program is " + count);}catch (Exception ex) {ex.printStackTrace();}}}*/21.4import java.util.Scanner;import java.util.HashSet;import java.util.Arrays;public class Exercise21_04 {public static void main(String[] args) throws Exception {HashSet<Character> set1 = new HashSet<Character>(Arrays.asList( new Character[]{'A', 'E', 'I', 'O', 'U'}));System.out.print("Enter a filename: ");Scanner input = new Scanner(System.in);String filename = input.nextLine();input = new Scanner(new java.io.File(filename));int countVowels = 0;int countConsonants = 0;while (input.hasNext()) {String s = input.nextLine().toUpperCase();for (int i = 0; i < s.length(); i++) {if (set1.contains(s.charAt(i)))countVowels++;else if (Character.isLetter(s.charAt(i)))countConsonants++;}}System.out.println("The number of vowels is " + countVowels + " and consonanats is " +countConsonants);}}21.5/*** Usage: Copy this class to the folder, run it with java JavaToHTMLftim * to generate* HTM file for all the .java file in this folder. The generated .htm files are* stored in the same folder*/import java.util.*;import java.io.*;public class Exercise21_05 {// Array of all Java keywords + true + false + nullstatic String[] keywordString = {"abstract", "assert", "boolean","break", "byte", "case", "catch", "char", "class", "const","continue", "default", "do", "double", "else", "enum","extends", "for", "final", "finally", "float", "goto", "if","implements", "import", "instanceof", "int", "interface","long", "native", "new", "package", "private", "protected","public", "return", "short", "static", "strictfp", "super","switch", "synchronized", "this", "throw", "throws","transient", "try", "void", "volatile", "while","true", "false", "null"};static Set<String> keywordSet =new HashSet<String>(Arrays.asList(keywordString));/** Main method */public static void main(String[] args) throws Exception {// Check usageif (args.length != 2) {System.out.println("Usage: java Exercise20_10 javaSourcefile htmlfile");System.exit(1);}Scanner input = new Scanner(new File(args[0]));PrintWriter output = new PrintWriter(new File(args[1]));JavaToHTML(input, output);}static boolean stringToken = false;static String inputFileName;public static void JavaToHTML(Scanner input, PrintWriter output) { try {output.format("%s\r\n", "<html>");output.format("%s\r\n", "<head>");output.format("%s\r\n","<title>Intro to Java Programming, 6E - " + inputFileName +"</title>");output.format("%s\r\n","<meta http-equiv=\"Content-Type\" content=\"text/html; charset=windows-1252\">");output.format("%s\r\n", "<style type = \"text/css\">");output.format("%s\r\n","body {font-family: \"Courier New\", sans-serif; font-size: 100%; color: black}");output.format("%s\r\n",".keyword {color: #000080; font-weight: bold}");output.format("%s\r\n", ".comment {color: #008000}");output.format("%s\r\n", ".literal {color: #0000ff}");// Match the color in the text// output.format("%s\r\n", ".keyword {color: black; font-weight: bold}");// output.format("%s\r\n", ".comment {color: #77797C}");// output.format("%s\r\n", ".literal {color: #007346; font-weight: bold}");output.format("%s\r\n", "</style>");output.format("%s\r\n", "</head>");output.format("%s\r\n", "<body>");output.format("%s\r\n", "<pre>");String text = "";String temp;// Read all lineswhile (input.hasNext()) {temp = input.nextLine();text += temp + "\r\n";}text = text.replaceAll(">", ">");text = text.replaceAll("<", "<");translateToHTML(text, input, output);output.format("%s\r\n", "</pre>");output.format("%s\r\n", "</body>");output.format("%s\r\n", "</html>");}catch (Exception ex) {System.out.println(ex);}finally {try {input.close();output.close();}catch (Exception ex) {}}}/** Translate Java source code to HTML */static void translateToHTML(String text, Scanner input, PrintWriter output) throws Exception {text = text.replaceAll("// ", "LINECOMMENT");text = text.replaceAll("/\\*", "BLOCKCOMMENT");String token;while (text != null && text.length() > 0) {// * and / are in conflict with /* and //String[] parts = text.split("[%\\+\\-\\*/\r\n\t \\[\\].;(){},]", 2); token = parts[0];if (token.length() > 1 && token.startsWith("LINECOMMENT")) {output.format("%s", "<span class = \"comment\">");parts = text.split("\r\n", 2);text = parts[1];output.format("%s", parts[0].replaceAll("LINECOMMENT", "// "));output.format("%s", "</span>\r\n");continue;}else if (token.length() > 1 && token.startsWith("BLOCKCOMMENT")) {output.format("%s", "<span class = \"comment\">");parts = text.split("\\*/", 2);text = parts[1];output.format("%s", parts[0].replaceAll("BLOCKCOMMENT", "/*") +"*/");output.format("%s", "</span>");continue;}else if (token.length() > 1 && token.matches("'\\w'*")) {output.format("%s", "<span class = \"literal\">");output.format("%s", token);output.format("%s", "</span>");}else if (token.startsWith("\"") && token.endsWith("\"") &&(token.length() > 1)) {output.format("%s", "<span class = \"literal\">" + token+ "</span>");}else if (token.startsWith("'") && token.endsWith("'") &&(token.length() > 1)) {output.format("%s", "<span class = \"literal\">" + token+ "</span>");}else if (token.equals("' '")) {output.format("%s", "<span class = \"literal\">" + token+ "</span>");}else if (token.startsWith("\"") && token.endsWith("\"") &&(token.length() == 1)) {if (stringToken) {output.format("%s", token + "</span>");stringToken = false;}else {output.format("%s", "<span class = \"literal\">" + token); stringToken = true;}}else if (token.startsWith("\"")) {output.format("%s", "<span class = \"literal\">" + token); stringToken = true;}else if (token.endsWith("\"") && (!token.endsWith("\\\""))) { output.format("%s", token);output.format("%s", "</span>");stringToken = false;}else if (token.matches("\\d+")) { // Check if numericoutput.format("%s", "<span class = \"literal\">" + token +"</span>");}else if (!stringToken && keywordSet.contains(token)) {output.format("%s", "<span class = \"keyword\">" + token +"</span>");}else {output.format("%s", token);}if (token.length() < text.length()) {if (text.charAt(token.length()) == '<')output.format("%s", "<");else if (text.charAt(token.length()) == '>')output.format("%s", ">");elseoutput.format("%s", text.charAt(token.length()));}if (parts.length == 2) {text = parts[1];}}}}21.6import java.util.*;public class Exercise21_06 {public static void main(String[] args) {// Create a tree map to hold words and key and count as value TreeMap<Integer, Integer> treeMap = new TreeMap<>();Scanner input = new Scanner(System.in);while (true) {// Enter an integerSystem.out.print("Enter an integer: ");int number = input.nextInt();if (number == 0) break;Integer key = new Integer(number);if (treeMap.get(key) != null) {int value = ((Integer)treeMap.get(key)).intValue();value++;treeMap.put(key, new Integer(value));}else {treeMap.put(key, new Integer(1));}}Integer max = Collections.max(treeMap.values());Set<Integer> keys = treeMap.keySet();Iterator<Integer> iterator = keys.iterator();while (iterator.hasNext()) {Object key = iterator.next();Integer value = (Integer)(treeMap.get(key));if (value.equals(max)) {System.out.println("Number " + key + " occurred most");}}}}21.7import java.util.*;public class Exercise21_07 {public static void main(String[] args) {// Text in a stringString text = "Have a good day. Have a good class. " + "Have a good visit. Have fun!";// Create a hash map to hold words and key and count as value HashMap<String, Integer> hashMap = new HashMap<>();String[] tokens = text.split("[ |.|!|?]");for (String key: tokens) {if (hashMap.get(key) != null) {hashMap.put(key, hashMap.get(key).intValue() + 1);}else {if (key.trim().length() > 0)hashMap.put(key, 1);}}// Get an entry set for the tree mapSet<Map.Entry<String, Integer>> entrySet = hashMap.entrySet();ArrayList<WordOccurrence> list = new ArrayList<>();for (Map.Entry<String, Integer> entry: entrySet) {list.add(new WordOccurrence(entry.getKey(), entry.getValue())); }Collections.sort(list);for (WordOccurrence item: list) {System.out.println(item);}}}class WordOccurrence implements Comparable<WordOccurrence> {String word;int count;public WordOccurrence(String word, int count) {this.word = word;this.count = count;}@Overridepublic int compareTo(WordOccurrence o) {return count - o.count;}@Overridepublic boolean equals(Object o) {return word.equals(((WordOccurrence)o).word);}@Overridepublic String toString() {return word + ": " + count;}}21.8import java.util.*;import java.io.*;public class Exercise21_08 {public static void main(String[] args) {if (args.length != 1) {System.out.println("Usage: java Exercise21_08 fullfilename");System.exit(1);}String filename = args[0];// Create a tree map to hold words as key and count as valueTreeMap<String, Integer> treeMap = new TreeMap<String, Integer>();try {Scanner input = new Scanner(new File(filename));while (input.hasNext()) {String line = input.nextLine();String[] words = line.split("[ @!~{}\\[\\]$#^&*\n\t\r.,;?'\")(]");for (int i = 0; i < words.length; i++) {if (words[i].trim().length() > 0 &&words[i].trim().matches("[A-Z|a-z]+")) {String key = words[i].toLowerCase();if (treeMap.get(key) != null) {int count = treeMap.get(key);count++;treeMap.put(key, count);}else {treeMap.put(key, 1);}}}}}catch (Exception ex) {ex.printStackTrace();}// Get an entry set for the tree mapSet<Map.Entry<String, Integer>> entrySet = treeMap.entrySet();// Display words in alphabetical orderSystem.out.println("\nDisplay words and their count in " + " ascending order of the words");for (Map.Entry<String, Integer> entry: entrySet)System.out.println(entry.getValue() + "\t" + entry.getKey()); }}21.9import java.util.*;public class Exercise21_09 {public static void main(String[] args) {String[][] stateCapital = {{"Alabama", "Montgomery"},{"Alaska", "Juneau"},{"Arizona", "Phoenix"},{"Arkansas", "Little Rock"},{"California", "Sacramento"},{"Colorado", "Denver"},{"Connecticut", "Hartford"},{"Delaware", "Dover"},{"Florida", "Tallahassee"},{"Georgia", "Atlanta"},{"Hawaii", "Honolulu"},{"Idaho", "Boise"},{"Illinois", "Springfield"},{"Indiana", "Indianapolis"},{"Iowa", "Des Moines"},{"Kansas", "Topeka"},{"Kentucky", "Frankfort"},{"Louisiana", "Baton Rouge"},{"Maine", "Augusta"},{"Maryland", "Annapolis"},{"Massachusettes", "Boston"},{"Michigan", "Lansing"},{"Minnesota", "Saint Paul"},{"Mississippi", "Jackson"},{"Missouri", "Jefferson City"},{"Montana", "Helena"},{"Nebraska", "Lincoln"},{"Nevada", "Carson City"},{"New Hampshire", "Concord"},{"New Jersey", "Trenton"},{"New York", "Albany"},{"New Mexico", "Santa Fe"},{"North Carolina", "Raleigh"},{"North Dakota", "Bismark"},{"Ohio", "Columbus"},{"Oklahoma", "Oklahoma City"},{"Oregon", "Salem"},{"Pennslyvania", "Harrisburg"},{"Rhode Island", "Providence"},{"South Carolina", "Columbia"},{"South Dakota", "Pierre"},{"Tennessee", "Nashville"},{"Texas", "Austin"},{"Utah", "Salt Lake City"},{"Vermont", "Montpelier"},{"Virginia", "Richmond"},{"Washington", "Olympia"},{"West Virginia", "Charleston"},{"Wisconsin", "Madison"},{"Wyoming", "Cheyenne"}};Map<String, String> map = new HashMap<String, String>();for (int i = 0; i < stateCapital.length; i++)map.put(stateCapital[i][0].toLowerCase(), stateCapital[i][1]);Scanner input = new Scanner(System.in);System.out.print("Enter a state: ");String state = input.nextLine().toLowerCase().trim();if (map.containsKey(state))System.out.println("The capital is " +map.get(state));elseSystem.out.println("No such state ");}}21.10import java.util.*;import java.io.*;public class Exercise21_10 {public static void main(String[] args) {// Prompt the user to enter a Java source fileScanner input = new Scanner(System.in);System.out.print("Enter a file name: ");String filename = input.nextLine();// Array of all Java keywords + true + nullString[] keywordString = { "abstract", "finally", "public", "boolean", "float", "return", "break", "for", "short", "byte", "goto", "static","case", "if", "super", "catch", "implements", "switch", "char","import", "synchronized", "class", "instanceof", "this", "const","int", "throw", "continue", "interface", "throws", "default", "long","transient", "do", "native", "try", "double", "new", "void", "else","package", "volatile", "extends", "private", "while", "final","protected", "true", "null" };Set<String> keywordSet = newHashSet<String>(Arrays.asList(keywordString));int count = 0;try {input = new Scanner(new File(filename));String text = "";while (input.hasNext()) {String line = input.nextLine();line = stripLineComments(line);line = stripLineStringLiterals(line);text += line + " ";}text = stripParagraghComments(text);TreeMap<String, Integer> map = new TreeMap<String, Integer>();String[] tokens = text.split("[ \\[,()\\]]");for (String token : tokens) {if (keywordSet.contains(token))if (map.get(token) == null) {map.put(token, 1);} else {int value = map.get(token);value++;map.put(token, value);}}// Get all entries into a setSet<Map.Entry<String, Integer>> entrySet = map.entrySet();// Get key and value from each entryfor (Map.Entry<String, Integer> entry: entrySet)System.out.println(entry.getValue() + "\t" + entry.getKey()); } catch (Exception ex) {ex.printStackTrace();}}/* Strip line comments */private static String stripLineComments(String line) {int index = line.indexOf("//");if (index < 0)return line;elsereturn line.substring(0, index);}/* Strip string literals */private static String stripLineStringLiterals(String line) {int start = line.indexOf("\"");int end = line.indexOf("\"", start + 1);while (start > 0 && end > 0) {line = line.substring(0, start) + line.substring(end + 1);start = line.indexOf("\"");end = line.indexOf("\"");}return line;}/* Strip paragraph comments */private static String stripParagraghComments(String text) {int start = text.indexOf("/*");int end = text.indexOf("*/");while (start > 0 && end > 0) {text = text.substring(0, start) + text.substring(end + 2);start = text.indexOf("/*");。
java常见面试题及答案第十套
final关键字除了修饰类之外，还有哪些用法呢?
final修饰的变量，一旦赋值，不可重新赋值;
final修饰的方法无法被覆盖;
final修饰的实例变量，必须手动赋值，不能采用系统默认值;
final修饰的实例变量，一般和static联用，用来声明常量;
注意：final不能和abstract关键字联合使用。
总之，final表示最终的、不可变的。
重载(overload)和重写(override)的区别?重载的方法能否根据返回类型进行区分?
方法的重载和重写都是实现多态的方式，区别在于前者实现的是编译时的多态性，而后者实现的是运行时的多态性。
重载发生在一个类中，同名的方法如果有不同的参数列表(类型不同、个数不同、顺序不同)则视为重载。
重写发生在子类与父类之间，重写要求子类重写之后的方法与父类被重写方法有相同的返回类型，比父类被重写方法更好访问，不能比父类被重写方法声明更多的异常(里氏代换原则)。
重载对返回类型没有特殊的要求。
Java复习题目（有答案）
Java复习题⽬（有答案）复习题⽬⼀．选择题（每⼩题2分,共30分）1.main()⽅法是Java Application程序执⾏的⼊⼝点，关于main()⽅法的⽅法头下⾯哪⼀项是合法的? ( )A.public static void main( )B.public static void main(String args[ ])C.public static int main(Stnng[ ]arg)D.public Void main(Stnng arg[ ])2.以下关于抽象类和接⼝的说法正确的是（）。
A. 抽象类可以⽤来定义接⼝B.定义抽象类时需要finalC. 抽象类中的所有⽅法都是具体的D.抽象类可以是对接⼝的实现3.下列不属于java.awt包中的基本概念的⼀项是( )。
A.容器B.构件C.线程D.布局管理器4.下列Swing构件中，属于中间容器的⼀项是( )。
A.JFrameB.JToolbarC.JLabelD.JButton5.使⽤JDBC的主要好处是（）。
A．它是⼀个简单易⽤的数据库管理系统B．允许开发者不⽤改变程序代码就可以改变底层的数据库C．它是多平台的数据管理系统D．它能为数据库管理系统提供了⼀个图形⽤户界⾯6.SQL语⾔中的字符串常量使⽤什么符号括起来（）？A．⼀对双引号（""）B．⼀对单引号（''）C．下划线（_）D．百分号（％）7.当程序执⾏时⽆法找到数据库驱动类时将产⽣（）异常。
A．NoSuchClassException B．ClassCastException C．ClassNotFoundException D．IllegalClassException8.在使⽤PreparedStatement时，参数是从（）开始计数的。
A．0 B．1 C．2 D．39.当对设有INSERT类型触发的数据表中的⼀条记录进⾏修改时，以下说法正确的是（）。
AnjoyoJava10课后习题带答案
AnjoyoJava10课后习题一、选择题：1.下列哪一个是计算机的联网不可以实现的功能（）。
A、使用远程资源B、共享信息、程序和数据C、分布处理D、共享硬件2.下列哪个不属于计算机网络按照网络拓扑结构可以分为（）的网络类型。
A、星型网络B、光导纤维C、总线网络D、环线网络3.下列关于网络工作模式说法不正确的是（）A、专用服务器结构，由若干台微机工作站与一台或多台文件服务器通过通信线路连接起来组成工作站存取服务器文件。
B、客户机/服务器模式，这种典型的用法是银行POS机。
C、客户机/服务器模式，其中一台或几台较大的计算机集中进行共享数据库的管理和存取，称为服务器。
D、对等式网络中没有专用服务器，每一个工作站既可以起客户机作用也可以起服务器作用。
4.下列关于OSI参考模型的说法不正确的是（）A、数据链路层是最底层，它是网络硬件设备之间的接口。
B、网络层通过网络连接交换网络服务数据单元。
C、会话层提供两个进程间的连接管理功能。
D、应用层是直接面对用户的一层，提供OSI用户服务。
5.下列关于TCP协议说法错误的是（）A、TCP协议它为两台计算机之间的连接起了重要作用。
B、TCP协议会让它们建立一个连接、发送和接收数据以及终止连接。
C、TCP协议被称作一种不可靠的端对端协议。
D、TCP重发一切没有收到的数据，进行数据内容准确性检查并保证分组的正确顺序。
6.下列关于IP协议说法错误的是（）。
A、Internet上的所有数据通过IP包的方式传输。
B、如果希望能在Internet上进行交流和通信，每台连上Internet的计算机都必须遵守IP协议。
C、IP是一个无连接、不可靠的协议。
D、IP协议重传已丢失的数据包或者监测受损害的数据。
7.下列属于A类IP类型的是（）。
A、126.110.2.15B、191.11.2.3C、192.2.3.52D、111.2.3.628.下述关于IP地址不正确的是：（）。
A、IP地址是数字型的，由32位(bit)二进制表示。
10级Java 试卷A
B. abstract方法允许出现在非abstract类中
C.Java字节流和字符流的区别在于每次读写的字节数不同
D.默认情况下，Applet禁止读写本地计算机上的文件
6.下列()是一个接口类型。
A.StringB.InputStreamC.ConnectionD.Socket
k = i;
for( j= i; j<x.length; j++ )
if( x[j]<x[k] ) k=j;
temp=x[i];
x[i]= x[k];
x[k]= temp;
}
for ( i=0; i<x.length; i++ )
System.out.print(x[i]);
}
}
2.以下程序的输出结果为＿＿＿＿＿。（5分）
}
}
class boy extends parent{
public boy(){来自boy.x++;
y++;
display();
}
public void display(){
System.out.println(x+","+y);
}
}
public class myPerson {
public static void main(String[] args){
1.以下程序的输出结果为＿＿＿＿＿。（5分）
public class mysort
{ public static void main(String args[ ]){
int i, j, k, temp;
AnjoyoJava10章节考试题
第十章考试题一、选择题：（每题3分，共60题）1.在 TCP/IP 参考模型中TCP协议工作在（）。
A、应用层B、传输层C、互连层D、主机-网络层2.Java提供的类InetAddress来进行有关Internet地址的操作（）。
A、SocketB、ServerSocketC、DatagramSocketD、InetAddress3.为了获取远程主机的文件内容，当创建URL对象后，需要使用哪个方法获取信息（）A、openStream()B、getPort()C、getHostD、openConnection()4.Java程序中，使用TCP套接字编写服务端程序的套接字类是（）。
A、SocketB、ServerSocketC、DatagramSocketD、DatagramPacket5.ServerSocket的监听方法accept()的返回值类型是（）。
A、voidB、ObjectC、SocketD、DatagramSocket6.ServerSocket的getInetAddress()的返回值类型是（）。
A、SocketB、ServerSocketC、InetAddressD、URL7.当使用客户端套接字Socket创建对象时，需要指定（）。
A、服务器主机名称和端口B、服务器端口和文件C、服务器名称和文件D、服务器地址和文件8.使用流式套接字编程时，为了向对方发送数据，则需要使用哪个方法（）。
A、getInputStream()B、getOutputStream()C、getInetAddress()D、getLocalPort()9.使用UDP套接字通信时，常用（）类把要发送的信息打包。
A、read()B、Listen()C、accept()D、receive()10.若要取得数据包的中源地址，可使用下列哪个语句（）。
A、getAddress()B、getPort()C、getName()D、getData()11.Java网络程序位于TCP/IP参考模型中的那一层( )。
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（难度系数 B）答案：对 知识点：内存回收 6．( ) abstract 和 final 不能同时修饰同一个类。
答案 对 难度 C 知识点：类的定义，修饰
7．（ ）访问类的成员，必须以类的对象为前缀。 答案 错 难度 C 知识点：类的封装，访问
8．（ ）诊断和改正程序中错误的工作通常称为程序执行。 答案：错；难度：C；知识点：编程基础。
1、Java 应用程序总是从主类的
方法开始执行。
知识点： 类概念
难度系数 C 答案
main
2、在 Java 中若定义抽象类则需要加关键字
来修饰。
答案：abstract ；难度：C；知识点：编程基础。
3、在子类中定义与父的相同的方法,若在多个子类中定义相同的方法，则可以调
用不同子类中的相同方法而实现不同的功能，这实现了程序运行时
知识点：异常处理
4. （ ）Java 是区分大小写的语言，关键字的大小写不能搞错，如果把类 class 写成 Class 或者 CLASS，都是错误的。
（难度系数 B）答案：对 知识点：关键字
5．（ ）JAVA 语言对内存的释放是采用垃圾自动回收机制。JAVA 虚拟机自动判 断并收集“垃圾”，但一般不立即释放它们的存储空间。
答案：应用（Application）、小程序（Applet）；难度：C；知识点：java 特性。
8、在 Java 程序中，通过类的定义只能实现
重继承，但通过接口的定
义可以实现
重继承关系。
答案：单、多；难度：B；知识点：java 特性。
9、字符串分为两大类，一类是字符串常量，使用
类的对象表示；
另一类是字符串变量，使用
大学 —— 学年第 学期
班 级
《 Java 程序设计 》课程试题
：
姓
名
密
：
课程号：
√考试 □考查
□A 卷 □B 卷
√闭卷 □开卷
题 号 一 二 三 四 五 六 七 八 九 十 总分 阅卷教师
各题分数 40 20 10 5 5 20
100
实得分数
学
号
：
封
一、单项选择题（20 题；每题 2 分，共 40 分）
答案： D 知识点： 类成员
难度系数C
4、下列语句正确的是________。
A）int a={1,2,3}
B）int b=(1,2,3);
C）int c[]={1,2,3}
D）int []d={1 2 3}
（难度系数 C）答案：C 知识点：数组
5、在编写异常处理的 Java 程序中，每个 catch 语句块都应该与＿＿＿语句块对
B) 线程 D) 服务
20、在 Java Applet 程序用户自定义的 Applet 子类中，一般需要重载父类的_____
方法来完成一些画图操作。
A) start( )
B) stop( )
C) init( )
D) paint( )
(难度系数 A，APPLET) 答案：D
二、填空题（10 题；每题 2 分，共 20 分）
的
。
答案：多态；难度：C；知识点：面向对象基础。
4、用来定义一个类指定继承父类的关键字是
，用来指定接口的
继承的关键字是
。答案：extends 、implements；难度：C；知识点：
语法基础。
5、java 提供的两种多态机制是
和
。.
答案 重载 、覆盖 难度(B) 知识点：多态机制
6、在 Java 程序运行时，系统自动通过 System 类创建三个静态的 I/O 对象，它们
public static void main(String args[ ]){ int i , j ; int a[ ] = { 5,9,6,8,7}; for ( i = 0 ; i < a.length-1; i ++ ) { int k = i; for ( j = i ; j < a.length ; j++ )
}
}
难度系数 C
知识点：JAVA 类与对象
答案：（1）int chinese（2）int math（3）return chinese+math+English
五、读程序写结果（1 题；每题 5 分，共 5 分）
1．写出下列程序在控制台窗口中的输出结果。
public class TestArray {
页
C）Java 是跨平台的编程语言
D）Java 支持多线程
加
答案：A 知识点： java 基础
难度系数 C
白 纸
3、定义私有的成员函数或成员变量，正确的是＿＿＿＿。
A）不需要定义，缺省的访问级就是私有级 B）在类的开头部分集中定义
张
C）成员函数需要定义，而成员变量不需要定义 D）利用private 关键字定义
13、在 Java 中，_______表示换行符的转义字符。
A）\n
B）\f
C）'n'
D）\dd
答案：A；难度：C；知识点：语法基础。
14、在 Java 中，所有类的根类是________。
A）ng.Object B）ng.Class
C）java.applet.Applet D）java.awt.Fram
A） abstract 不能与 final 并列修饰同一个类 B） abstract 类中不可以有 private
的成员
C）abstract 方法必须在 abstract 类中
D）static 方法中能处理非 static 的
属性
答案： D 难度系数： A
知识点：关键字
17、下面＿＿＿函数是 public void aMethod(){...}的重载函数。 A) void aMethod( ){...} B) public int aMethod(){...} C) public void aMethod ( ){...} D) public int aMethod ( int m){...}
} }
答案：5 6
if ( a[j]<a[k] ) k = j; int temp =a[i]; a[i] = a[k]; a[k] = temp; } for ( i =0 ; i<a.length; i++ )
System.out.print(a[i]+" "); System.out.println( );
类的对象表示。
答案：String、StringBuffer；难度：B；知识点：变量类型。
10、在定义类时，指明类成员的权限修饰符有
、
和
。
答案 public protected private 难度 B 知识点：类的定义
三、判断题（10 题；每题 1 分，共 10 分）
1. ( ) Java语言属于高级程序设计语言。
9. ( ) 即使一个类中未显式定义构造函数，也会有一个缺省的构造函数，缺省
的构造函数是无参的，函数体为空。
答案：对
难度系数： C
知识点：构造函数
10. ( )用 Javac 编译 Java 源文件后得到代码叫字节码。 （难度系数 B）答案：错 知识点：JAVA 简介
四、程序填空题（1 题；每题 5 分，共 5 分）
答案：对 知识点： java 基础
难度系数 C
2. ( )字符串 "\'a\'" 的长度是 5。 答案：错；难度：B；知识点：语法基础
3．( ) 在异常处理中总是将可能产生异常的语句放在 try 块中，用 catch 子句
去处理异常，而且一个 try 块之后只能对应一个 catch 语句。
答案：错
难度系数： B
答案：A；难度：C；知识点：编程基础。
15、_________事件监听器可以处理在文本框中输入回车键的事件
A）ItemListener
B）ActionListener
C）MotionListener
D）AdjustListener
（难度系数 B）答案：B 知识点：事件处理
16、下列关于修饰符混用的说法，错误的是＿＿＿。
1．下面程序是定义一个 Student 类，在空白处填入适当语句补充完整。
class student
{
String name;
int age;
（1）
;//定义一个整型属性 chinese
（2） ;//定义一个整型属性 math
int english;
int total()
{
（3）
;//返回 chinese、math 和 english3 个整型属性的总和。
答案： D 知识点： 变量
难度系数C
7、下列陈述正确的是_________。
A） 一个组件只能发生一种事件 B）一个监听器处理一种事件
C）多个事件监听器被注册到一个组件会引起编译错误
D） 如果多个事件监听器被注册到一个组件上，这些事件监听器一般都会起作
用，但各个事件的处理顺序不确定
（难度系数 A）答案：D 知识点：事件处理
答案：B；难度：B；知识点：窗体与控件。
10、下列关于构造方法的叙述中，错误的是＿＿＿＿。
A）Java 语言规定构造方法名与类名必须相同
B）Java 语言规定构造方法没有返回值，但不用 void 声明
C）Java 语言规定构造方法不可以重载
D）Java 语言规定构造方法只能通过 new 自动调用
答案：C 知识点：类
应，使得用该语句块来启动 Java 的异常处理机制。
A） if –y
D） throw