二级java考试真题(2)

public class Java_1{

public static void main(String[] args){

//*********Found******** String[] awt = new ______[3]; awt[0] = \"Abstract\"; awt[1] = \"Window\"; awt[2] = \"Tool kit\";

for (int i = 0; i < 3; i++)

//*********Found******** System.out.println(______); } }

1）String 2）填\"awt[i]\"

2.

public class Java_2 implements ActionListener{ Frame f; Button b; TextField tf;

public Java_2(){

f = new Frame(\"Show Date\");

//*********Found******** ______(new FlowLayout()); f.setSize(300,100);

//注册关闭窗口的

f.addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent e){ System.exit(0); } });

b = new Button(\"显示当前日期\");

//*********Found******** ______(this);

tf = new TextField(30); f.add(b);

f.add(tf);

f.setVisible(true); }

public static void main(String[] args) { Java_2 t = new Java_2(); }

public void actionPerformed(ActionEvent e){ Date d = new Date(); //获取当前日期。 tf.setText(d.toString()); } }

填\"f.setLayout\"，填\"b.addActionListener\"。 具体程序如下：

3.

import java.awt.*;

import java.awt.event.* ;

//*********Found********

public class Java_3 ______ ActionListener {

public static void main(String args[ ]) {

Java_3 tb = new Java_3();

Frame f = new Frame(\"Button Test\"); f.setSize(200,100);

f.setLayout(new FlowLayout(FlowLayout.CENTER));

Button b = new Button(\"Press the Button!\"); //*********Found******** b.______(tb);

f.add(b);

f.setVisible(true) ; }

public void actionPerformed(ActionEvent e) {

Frame fr = new Frame(\"An Other\"); fr.setBackground(Color.green);

fr.add(new Label(\"This frame shows when \"+\"pressing the button in Button Test\")); fr.pack();

fr.setVisible(true) ;

} }

填\"implements\填\"addActionListener\"。

15

1. import javax.swing.JOptionPane; public class Java_1{

public static void main( String args[] ) {

String output = \"\"; int count;

//*********Found********

for(count=1;count<=10; ______){ //*********Found******** if(count______)

break; // 当count为5时跳出循环 output += count + \" \"; }

output += \"\\nBroke out of loop at count = \" + count; JOptionPane.showMessageDialog( null, output ); System.exit( 0 ); } }

即\"count++\"或\"++count\填\">=5\"或\">4\"。

2. import java.io.*;

public class Java_2{

public static void main(String[] args) {

//*********Found********

int[] anArray=______; // 声明并创建包含10个元素的整型数组。 int i = 0; int total=0; try{

// 从data.dat中读出10个整数，放在整型数组中。

DataInputStream in = new DataInputStream(new FileInputStream(\"data.dat\")); while(in.available() != 0){ //*********Found******** anArray[i++]=in.______; }

in.close();

//将整型数组中的10个整数相加，并将这些数及其和显示输出。 System.out.print(\"Numbers: \");

for( i = 0; i < anArray.length; i++){ total = total+anArray[i]; if( iSystem.out.print(anArray[i]); System.out.print(','); } else{

System.out.println(anArray[i]); } }

System.out.println(\"Total: \"+total); }catch(IOException e1){} } }

填\"new int[10]\"。填\"readInt()\"。

3. import java.awt.*; import java.awt.event.*;

//*********Found******** import javax.______.*; import java.io.*;

public class Java_3 {

public static void main(String[] args) {

ExceptTestFrame frame = new ExceptTestFrame();

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); } }

class ExceptTestFrame extends JFrame {

public ExceptTestFrame() {

setTitle(\"ExceptTest\");

Container contentPane = getContentPane(); ExceptTestPanel panel = new ExceptTestPanel(); contentPane.add(panel); pack(); } }

class ExceptTestPanel extends Box

{

public ExceptTestPanel() {

super(BoxLayout.Y_AXIS); group = new ButtonGroup();

addRadioButton(\"Integer divide by zero\ ActionListener() {

public void actionPerformed(ActionEvent event) {

a[1] = 1 / (a.length - a.length); } });

textField = new JTextField(30); //*********Found******** add(______); }

private void addRadioButton(String s, ActionListener listener) {

JRadioButton button = new JRadioButton(s, false) {

protected void fireActionPerformed(ActionEvent event) {

try {

//*********Found********

textField.______(\"No exception\"); super.fireActionPerformed(event); }

catch (Exception exception) {

textField.setText(exception.toString()); } } };

button.addActionListener(listener); add(button);

group.add(button); }

private ButtonGroup group; private JTextField textField;

private double[] a = new double[10]; }

填\"swing\"。填\"textField\"。填\"setText\"。

16

1. class Variable{ int x=0,y=0,z=0; void init(int x,int y){

//*********Found******** ______=x; this.y=y;

int z=5; //局部变量

System.out.println(\"*****在初始化中*****\");

System.out.println(\"x = \"+x+\" y = \"+y+\" z =\"+z); } }

public class Java_1{

public static void main (String[] args){ //*********Found******** Variable v = new ______;

System.out.println(\"*****在初始化之前*****\");

System.out.println(\"x = \"+v.x+\" y = \"+v.y+\" z =\"+v.z); v.init(20,30);

System.out.println(\"*****在初始化之后*****\");

System.out.println(\"x = \"+v.x+\" y = \"+v.y+\" z =\"+v.z); } }

填\"this.x\"，填\"Variable()\"。 2. import java.io.*;

public class Java_2{

public static void main(String[] args) {

int[] anArray = new int[10]; // 声明并创建包含10个元素的整型数组。 int i = 0; int total=0; try{

// 从data.dat中读出10个整数，放在整型数组中。

//*********Found********

DataInputStream in=new DataInputStream(new ______(\"data.dat\")); while(in.available() != 0){ anArray[i++] = in.readInt(); }

in.close();

//将整型数组中的10个整数相加，并将这些数及其和显示输出。 for ( i = 0; i < anArray.length; i++){

//*********Found******** total=______;

if (iSystem.out.print(anArray[i]); System.out.print('+'); } else{

System.out.print(anArray[i]); }

}

System.out.println(\" = \"+total); }catch(IOException e1){} } }

填\"FileInputStream\"。填\"total+anArray[i]\"或写成\"anArray[i]+total\"。

3. public class Java_3 {

public static void main(String[] args) {

String num;

if(args.length > 0)

//*********Found******** num=______; else

num = \"5\";

//*********Found********

int input=Integer.parseInt(_____); int result = Java_3(input);

System.out.println(input+ \" 的阶乘是 \"+ result); }

public static int Java_3(int x) {

if( x < 0 ) return 0; int fact = 1; while(x > 1) {

//*********Found******** fact=______*x;

x = x-1; }

return fact; } }

填\"args[0]\"。填\"num\"。填\"fact\"。

17

1. import javax.swing.JOptionPane; public class Java_1 {

public static void main( String args[] ) { String output = \"\";

//*********Found********

for(int count=1;count<=10;______){ //*********Found******** if(count______)

continue; // 当count为5时跳过循环中的剩余代码 output += count + \" \"; }

output += \"\\nUsed continue to skip printing 5\"; JOptionPane.showMessageDialog( null, output ); System.exit( 0 ); } }

即\"count++\"或\"++count\"。填\"==5\"。

2. import java.awt.*; import java.awt.event.*; import java.util.*;

public class Java_2 implements ActionListener{ Frame f; Button b; TextField tf;

//*********Found******** public ______(){

f = new Frame(\"Show Date\"); f.setLayout(new FlowLayout()); f.setSize(400,100);

//注册窗口（WindowListener） //*********Found******** ______(new WindowAdapter(){

public void windowClosing(WindowEvent e){ System.exit(0);

} });

b = new Button(\"显示当前日期\"); b.addActionListener(this); tf = new TextField(30); f.add(b); f.add(tf);

f.setVisible(true); }

public static void main(String[] args) { Java_2 t = new Java_2(); }

public void actionPerformed(ActionEvent e){ Date d = new Date(); //获取当前日期。 tf.setText(d.toString()); } }

填\"Java_2\"；填\"f.addWindowListener\"。

3. import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.io.*;

public class Java_3 {

public static void main(String[] args) {

ExceptTestFrame frame = new ExceptTestFrame();

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); } }

class ExceptTestFrame extends JFrame {

public ExceptTestFrame() {

setTitle(\"ExceptTest\");

Container contentPane = getContentPane(); ExceptTestPanel panel = new ExceptTestPanel(); contentPane.add(panel);

pack(); } }

class ExceptTestPanel extends Box {

public ExceptTestPanel() {

super(BoxLayout.Y_AXIS); group = new ButtonGroup();

addRadioButton(\"整数被零除\ ActionListener() {

//*********Found********

public void ______(ActionEvent event) {

//*********Found********

a[1]=1/(a.length-a.______); } });

textField = new JTextField(30); add(textField); }

private void addRadioButton(String s, ActionListener listener) {

JRadioButton button = new JRadioButton(s, false) {

protected void fireActionPerformed(ActionEvent event) {

try {

textField.setText(\"No exception\"); super.fireActionPerformed(event); }

catch (Exception exception) {

//*********Found********

textField.______(exception.toString()); } } };

button.addActionListener(listener); add(button);

group.add(button); }

private ButtonGroup group; private JTextField textField;

private double[] a = new double[10]; }

填\"actionPerformed\"。 填\"length\"，填\"setText\"。

18

1. import javax.swing.JOptionPane;

public class Java_1 { int x= 0;

//*********Found******** String s = ______;

public static void main( String args[] ){ //*********Found******** Java_1 d = new ______; String output;

output = \"After instantiation:\\n\" + \"x : \"+d.x+\" s : \"+d.s; d.x = 77; d.s = \"Good bye\";

output += \"\\nAfter changing values:\\n\" + \"x : \"+d.x+\" s : \"+d.s; JOptionPane.showMessageDialog( null, output, \"Demonstrating Package Access\

JOptionPane.INFORMATION_MESSAGE ); System.exit( 0 ); } }

填字符串\"\"Hello\"\"。填\"Java_1()\"。

2. import java.io.*;

public class Java_2 {

public static void main(String[] args) {

int[] intArray = {1,2,3,4,5}; int j ;

try {

DataOutputStream out = new DataOutputStream( new FileOutputStream(\"data.dat\")); for(j =0; j{

//*********Found********

out.______(intArray[j]); }

out.close();

DataInputStream in = new DataInputStream( //*********Found********

new ______(\"data.dat\")); while(in.available() != 0) {

j = in.readInt();

System.out.println(j); }

in.close(); }

catch(IOException e){} } }

填\"writeInt\"。填\"FileInputStream\"。

3. import java.awt.*; import java.awt.font.*; import java.awt.geom.*; import javax.swing.*;

public class Java_3 {

public static void main(String[] args) {

FontFrame frame = new FontFrame();

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); } }

//*********Found******** class FontFrame ______ JFrame {

public FontFrame() {

setTitle(\"沁园春.雪\");

setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); FontPanel panel = new FontPanel();

Container contentPane = getContentPane();

contentPane.add(panel); }

public static final int DEFAULT_WIDTH = 300; public static final int DEFAULT_HEIGHT = 200; }

//*********Found******** class FontPanel extends ______ {

public void paintComponent(Graphics g) {

super.paintComponent(g);

Graphics2D g2 = (Graphics2D)g;

String message = \"数风流人物，还看今朝！\"; Font f = new Font(\"隶书\ g2.setFont(f);

FontRenderContext context = g2.getFontRenderContext(); Rectangle2D bounds = f.getStringBounds(message, context); double x = (getWidth() - bounds.getWidth()) / 2; double y = (getHeight() - bounds.getHeight()) / 2; double ascent = -bounds.getY(); double baseY = y + ascent; g2.setPaint(Color.RED); //*********Found********

g2.draw______(message, (int)x, (int)(baseY)); } }

填\"extends\"。填\"JPanel\"。填\"String\"。

19

1. import java.io.*;

public class Java_1 {

public static void main(String args[]) {

//*********Found******** ____ a='h'; byte b=6; int i=200; long n=567L;

//*********Found******** _____ f=98.99f; double d=4.7788; int aa=a+i;

long nn=n-aa; float ff=b*f;

double dd=ff/aa+d;

System.out.println(\"aa=\"+aa); System.out.println(\"nn=\"+nn); System.out.println(\"ff=\"+ff); System.out.println(\"dd=\"+dd); } }

填\"char\"或\"byte\"或\"short\"或\"int\"。填\"float\"。

2. //*********Found******** public class Java_2 extends ______ {

public static void main(String args[ ]) {

Java_2 t = new Java_2(); //*********Found******** t.______; }

public void run( ) {

int i = 0; while( true ) {

System.out.println(\"你好! \"); if (i++==4) break ; }

System.out.println(); } }

填\"Thread\"。填\"start()\"。

3. import java.awt.*; import java.awt.event.*; import java.util.*; import javax.swing.*; import javax.swing.Timer;

public class Java_3 {

public static void main(String[] args) {

//*********Found********

ActionListener listener = new ______();

Timer t = new Timer(1000, listener); t.start();

JOptionPane.showMessageDialog(null, \"Quit program?\"); System.exit(0); } }

//*********Found******** class TimePrinter ______ ActionListener {

public void actionPerformed(ActionEvent event) {

Date now = new Date();

System.out.println(\"At the tone, the time is \" + now); Toolkit.getDefaultToolkit().beep(); } }

填\"TimePrinter\"。填\"implements\"。

20

1. import java.io.*;

public class Java_1 {

public static void main(String args[]) {

char a='h'; byte b1=6;

//*********Found******** ______ i=200;

//*********Found******** ______ b=567L; float f=98.99f; double d=4.7788; int aa=a+i; long bb=b-aa; float ff=b1*f;

double dd=ff/aa+d;

System.out.println(\"aa=\"+aa); System.out.println(\"bb=\"+bb); System.out.println(\"ff=\"+ff); System.out.println(\"dd=\"+dd); } }

填\"short\"或\"int\"。填\"long\"。

2. import java.awt.* ; import java.applet.* ;

//*********Found******** public class Java_2 ______ {

int num;

public void init() {

//*********Found********

String s = getParameter(______); //从html文件中获取参数 num = Integer.parseInt(s); }

public void paint(Graphics g) {

for( int i=0; ig.drawString(\"Hello!\ } } }

填\"extends Applet\"或\"extends javax.swing.JApplet\"。填\"\"num\"\"。

3. import javax.swing.*; import java.awt.*;

public class Java_3 {

public static void main(String[] args) {

WelcomFrame frame = new WelcomFrame();

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //*********Found******** frame.setVisible(______); } }

//*********Found******** class WelcomFrame ______ JFrame {

public WelcomFrame() {

setTitle(\"Java等级考试\");

setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); WelcomPanel panel = new WelcomPanel(); Container contentPane = getContentPane(); contentPane.add(panel); }

public static final int DEFAULT_WIDTH = 250; public static final int DEFAULT_HEIGHT = 100; }

//*********Found********

class WelcomPanel extends ______ {

public void paintComponent(Graphics g) {

super.paintComponent(g);

g.drawString(\"欢迎参加Java等级考试！\ setBackground(Color.white); }

public static final int MESSAGE_X = 60; public static final int MESSAGE_Y = 50; }

填\"true\"。填\"extends\"。填\"JPanel\"。

21

1. import java.io.*; public class Java_1 {

public static void main(String args[]) {

char a='p'; byte b1=6; int i=400; long b=345L; float f=98.99f; double d=4.7788;

//*********Found******** ______ aa=a+i; long bb=b-aa;

//*********Found******** ______ ff=b1*f;

double dd=ff/aa+d;

System.out.println(\"aa=\"+aa); System.out.println(\"bb=\"+bb);

System.out.println(\"ff=\"+ff); System.out.println(\"dd=\"+dd); } }

填\"int\"或\"long\"。填\"float\"。

2. import java.awt.*; import javax.swing.*;

//*********Found********

public class Java_2 extends ______ {

public void init() {

Container contentPane = getContentPane();

JLabel label = new JLabel(\"Java的诞生是对传统计算模式的挑战！\ SwingConstants.CENTER); contentPane.add(label); } }

填\"JApplet\"。填\"Java_2.class\"；填\"HEIGHT\"。

3. import java.awt.*; import javax.swing.*;

public class Java_3 extends JApplet {

//*********Found******** public void _____() {

Container contentPane = getContentPane(); //*********Found******** JLabel label = new ______

(\"Java是一个跨平台的面向网络的计算机语言。\ SwingConstants.CENTER); //*********Found******** contentPane.add(_____); } }

填\"init\"或\"start\"。填\"JLabel\"，填\"label\"。

22

1. import java.io.*;

public class Java_1 {

public static void main(String args[])

{

char a='x'; byte b1=6; int i=100; long b=7L; float f=98.99f; double d=4.7788; int aa=a+i;

//*********Found******** ______ bb=b-aa; float ff=b1*f;

//*********Found******** ______ dd=ff/aa+d;

System.out.println(\"aa=\"+aa); System.out.println(\"bb=\"+bb); System.out.println(\"ff=\"+ff); System.out.println(\"dd=\"+dd); } }

填\"long\"。填\"double\"。

2. import java.awt.*; import java.awt.event.*; import java.util.*;

public class Java_2 implements ActionListener{ Frame f; Button b; TextField tf;

public Java_2(){

f = new Frame(\"Show Words\"); f.setLayout(new FlowLayout()); f.setSize(400,100);

//注册关闭窗口的

f.addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent e){ System.exit(0); } });

b = new Button(\"显示字符串\");

//*********Found********

______(this); //给按钮注册 f.add(b);

tf = new TextField(30);

//*********Found********

______(tf); //将文本框添加到窗口中 f.setVisible(true); }

public static void main(String[] args) { Java_2 t = new Java_2(); }

public void actionPerformed(ActionEvent e){ tf.setText(\"祝你成功！\"); } }

填\"b.addActionListener\"。填\"f.add\"。

3. //打印无符号整数位 import java.awt.*;

import java.awt.event.*; import javax.swing.*;

public class Java_3 extends JFrame { public Java_3(){

super( \"打印无符号整数位\" ); Container c = getContentPane(); c.setLayout( new FlowLayout() );

c.add( new JLabel( \"请输入整数: \" ) );

final JTextField output = new JTextField( 33 ); JTextField input = new JTextField( 10 ); input.addActionListener( new ActionListener() {

public void actionPerformed( ActionEvent e ){ int val = Integer.parseInt( e.getActionCommand() ); output.setText( getBits( val ) ); } } );

c.add( input );

c.add( new JLabel( \"该数的二进制位表示是\" ) ); output.setEditable( false );

//*********Found******** c.add( __output____ );

setSize( 720, 70 ); show(); }

private String getBits( int value ){ int displayMask = 1 << 31;

StringBuffer buf = new StringBuffer( 35 ); for ( int c = 1; c <= 32; c++ ) { buf.append(

( value & displayMask ) == 0 ? '0' : '1' ); value <<= 1; if ( c % 8 == 0 )

buf.append( ' ' ); }

return buf.toString(); }

public static void main( String args[] ){ Java_3 app = new Java_3(); app.addWindowListener( new WindowAdapter() { //*********Found********

public void windowClosing( _WindowEvent__ e ){ System.exit( 0 ); } } ); } }

23

1. import java.io.*;

public class Java_1 {

public static void main(String args[]) {

//*********Found******** ______ a='w'; byte b1=6; int i=500; long b=123L;

float f=98.99f; double d=4.7788; //*********Found******** ______ aa=a+i; long bb=b-aa; float ff=b1*f; double dd=ff/aa+d;

System.out.println(\"aa=\"+aa); System.out.println(\"bb=\"+bb); System.out.println(\"ff=\"+ff); System.out.println(\"dd=\"+dd); } }

填\"byte\"或\"short\"或\"char\"或\"int\"或\"long\"。填\"int\"或\"long\"。

2. public class Java_2 {

public static void main(String[] args) { //*********Found********

int[][] aMatrix = new ______[];

int i = 0; int j = 0; int k = 0;

//*********Found******** for ( i = 0; i < ______; i++) {

aMatrix[i]=new int[j+1]; //创建数组。

//给每个数组元素赋值并在一行中打印输出。 for ( k = 0; k < aMatrix[i].length; k++) { aMatrix[i][k]=k+1;

System.out.print(aMatrix[i][k] + \" \"); } j++;

System.out.println(); //换行。 } } }

填\"int[6][]\"。填\"aMatrix.length\"。

3. //if语句实例

import javax.swing.JOptionPane;

public class Java_3 {

public static void main( String args[] ){

String firstNumber, //存储第1个输入数据 secondNumber, //存储第2个输入数据 result; //字符串输出

int number1, //用来比较的第1个int型数据 number2; //用来比较的第2个int型数据 //以字符串格式读输入数据 firstNumber =

JOptionPane.showInputDialog( \"请输入第1个整数:\" ); secondNumber =

JOptionPane.showInputDialog( \"请输入第2个整数:\" ); //将字符串转换为int整数 //*********Found********

number1 = Integer.parseInt( __________ ); number2 = Integer.parseInt( secondNumber ); //用空字符串初始化结果变量 result = \"\";

if ( number1 == number2 )

result = number1 + \" == \" + number2; if ( number1 != number2 )

result = number1 + \" != \" + number2; if ( number1 < number2 )

result = result + \"\\n\" + number1 + \" < \" + number2; if ( number1 > number2 )

result = result + \"\\n\" + number1 + \" > \" + number2; if ( number1 <= number2 )

result = result + \"\\n\" + number1 + \" <= \" + number2; if ( number1 >= number2 )

result = result + \"\\n\" + number1 + \" >= \" + number2; //显示结果

JOptionPane.showMessageDialog( null, result, \"比较结果\ //*********Found******** JOptionPane.__________ ); System.exit( 0 ); } }

填入\"firstNumber\"

JOptionPane.INFORMATION_MESSAGE);

24

1. import java.io.*;

public class Java_1 {

public static void main(String args[]) {

//*********Found********

______ double TQ_IN=8.88; //定义常量

byte b; int i;

//*********Found******** ______ c;

double d=2.79994;

b=011; i=234; c='q';

System.out.println(\"TQ_IN= \"+TQ_IN); System.out.println(\"b= \"+b); System.out.println(\"i= \"+i); System.out.println(\"c= \"+c); System.out.println(\"d= \"+d); } }

填\"final\"。填\"char\"。

2. import java.awt.*; import java.awt.event.*;

//*********Found********

public class Java_2 extends Frame __ implements ______ ActionListener{ public static void main(String args[ ]){ Java_2 fr = new Java_2(\"Test\"); fr.setSize(200,200);

fr.setLayout(new GridLayout(2,1));

Button b = new Button(\"退出\"); //*********Found********

b.addActionListener(new __Java_2______()); fr.add(b);

fr.setVisible(true); }

public void actionPerformed( ActionEvent e){ System.exit(0);

}

public Java_2(String str){ super(str); }

public Java_2( ){ } }

3. import java.awt.*; import java.awt.event.*;

//*********Found********

public class Java_3 implements ActionListener,__ WindowListener ____ {

Frame f;

Button be,bw,bs,bn,bc; public void create() {

f=new Frame(\"Exit test\"); be=new Button(\"East\"); bw=new Button(\"West\"); bs=new Button(\"South\"); bn=new Button(\"North\"); bc=new Button(\"Exit\"); f.add(be,\"East\"); f.add(bw,\"West\"); f.add(bs,\"South\"); f.add(bn,\"North\"); f.add(bc,\"Center\");

bc.addActionListener(this);//为按钮注册 f.addWindowListener(this); f.setSize(200,200); f.setVisible(true); }

public static void main(String args[]) {

//*********Found********

Java_3 fa=___ Java_3() _______; fa.create(); }

public void actionPerformed(ActionEvent e) {

//*********Found********

___ System.exit _______(0); //实现窗口关闭功能 }

public void windowOpened(WindowEvent e){} public void windowClosing(WindowEvent e) {

//*********Found********

____ System.exit _______(0); //实现窗口关闭功能 }

public void windowClosed(WindowEvent e){} public void windowIconified(WindowEvent e){} public void windowDeiconified(WindowEvent e){} public void windowActivated(WindowEvent e){} public void windowDeactivated(WindowEvent e){} } 25

1. import java.io.*;

public class Java_1 {

//*********Found********

public static ______ main(String args[]) {

final double TQ_IN=188.88;

long b; int i;

//*********Found******** ______ c;

double d=2.79994;

b=0456; i=1024; c='U';

System.out.println(\"TQ_IN= \"+TQ_IN); System.out.println(\"b= \"+b); System.out.println(\"i= \"+i); System.out.println(\"c= \"+c);

System.out.println(\"d= \"+d); } }

填\"void\"。填\"char\"。

2. public class Java_2 {

public static void main(String[] args) { int[][] aTriangle = new int[6][]; int i = 0; int j = 6; int k = 0;

for ( i = 0; i < aTriangle.length; i++) {

aTriangle[i]=new int[j]; //创建数组。

//给每个数组元素赋值并在一行中打印输出。 //*********Found******** for ( k = 0; k < ______; k++) { aTriangle[i][k]=k+1; //*********Found********

System.out.print(______ + \" \"); } j--;

System.out.println(); //换行。 } } }

填\"aTriangle[i].length\"。填\"aTriangle[i][k]\"。

3. //程序的功能是从1开始，每秒打印一个递增的整数。 import java.awt.*;

import java.awt.event.*; import java.util.*; import javax.swing.*; import javax.swing.Timer;

public class Java_3{

public static void main(String[] args){

ActionListener listener = new TimePrinter(); //*********Found********

Timer t = new Timer(1000, __ ActionListener ________); t.start();

JOptionPane.showMessageDialog(null, \"退出程序?\"); System.exit(0); } }

//*********Found********

class TimePrinter implements __________{ //*********Found********

public void action____ actionPerformed ______(ActionEvent event){ i++;

System.out.println(i);

Toolkit.getDefaultToolkit().beep(); }

int i = 0; }

26

1. //使用标记的break语句

import javax.swing.JOptionPane;

public class Java_1 {

public static void main( String args[] ){ String output = \"\"; //标注复合语句 stop: {

for ( int row = 1; row <= 10; row++ ) {

for ( int column = 1; column <= 5 ; column++ ) { if ( row == 5 ) //*********Found********

break __ stop ____; output += \"* \"; }

output += \"\\n\"; }

//跳过下一行

output += \"\\n循环正常终止\"; }

JOptionPane.showMessageDialog( //*********Found********

null, output,\"__ 用标记的break语句测试成功!____\ JOptionPane.INFORMATION_MESSAGE ); System.exit( 0 ); } }

2. import java.awt.*; import java.awt.event.*;

//*********Found********

public class Java_2 ________ Frame implements ActionListener{ public static void main(String args[]){ Java_2 fr = new Java_2(\"Hello !\");

fr.setLayout( new FlowLayout()); fr.setSize(200,100);

fr.setBackground(Color.blue); Button b = new Button(\"确定\"); //*********Found******** b.________(new Java_2()); fr.add(b);

fr.setVisible(true); }

public void actionPerformed( ActionEvent e){ System.exit(0); }

public Java_2(String str){ super(str); }

public Java_2( ){ } }

填\"extends\"。填addActionListener 。

3. import java.text.*;

public class Java_3{

public static void main(String[] args){

Person p = new Student(\"王甜甜\计算机科学\");

System.out.println(p.getName() + \ } }

abstract class Person{

public Person(String n){ name = n; }

//*********Found********

public _abstract_____ String getDescription(); public String getName(){ return name; }

private String name; }

//*********Found******** class Student __ extends ____ Person{ public Student(String n, String m){ super(n); major = m; }

//*********Found********

public String _getDescription_____(){ return \"学生专业是:\" + major; }

private String major; } 27

1. //用目标标记的Continue语句实例 import javax.swing.JOptionPane;

public class Java_1 {

public static void main( String args[] ){ String output = \"\";

nextRow:

for ( int row = 1; row <= 5; row++ ) { output += \"\\n\";

for ( int column = 1; column <= 10; column++ ) { if ( column > row ) //*********Found********

continue __nextRow________; output += \"* \"; } }

JOptionPane.showMessageDialog( //*********Found********

null, output,\"__ Testing continue with a label ________\ JOptionPane.INFORMATION_MESSAGE ); System.exit( 0 ); } }

2. import java.awt.*; import java.awt.event.*;

public class Java_2 extends Frame implements WindowListener { //*********Found******** public _ Java_2_____() {

setLayout(new FlowLayout()); add(new Button(\"Button 1\")); add(new Button(\"2\"));

add(new Button(\"Button 3\")); //*********Found******** addWindowListener(this);

}

public static void main(String args[]) { Java_2 window = new Java_2(); window.setTitle(\"AWT Test\"); window.pack(); window.show(); }

public void windowClosing(WindowEvent e) { System.exit(0); }

public void windowClosed(WindowEvent e) { } public void windowOpened(WindowEvent e) { } public void windowIconified(WindowEvent e) { } public void windowDeiconified(WindowEvent e) { } public void windowActivated(WindowEvent e) { } public void windowDeactivated(WindowEvent e) { } }

3. //程序的功能是求以命令行参数指定的整数的阶乘。 public class Java_3{

public static void main(String[] args){ String num;

if(args.length > 0)

//*********Found******** num = __________; else

num = \"5\";

//*********Found********

int input = Integer.parseInt(__________); double result = factorial(input);

System.out.println(input+ \" 的阶乘是 \"+ result); }

public static double factorial(int x){ if( x < 0 ) return 0.0;

double fact = 1.0; while(x > 1){

//*********Found******** fact __________ *x; x = x-1; }

return fact; } }

填\"args[0]\"。 填\"num\"。填\"=fact\"。