二级Java程序题--03综合应用：源代码（01-42）
目录
3.综合应用
3.1
3.2
3.3
3.4
3.5
3.6（*）
3.7
3.8
3.9
3.10
3.11
3.12
3.13
3.14
3.15
3.16
3.17
3.18
3.19
3.20
3.21
3.22
3.23
3.24
3.25
3.26
3.27
3.28
3.29
3.30
3.31
3.32
3.33
3.34
3.35
3.36
3.37
3.38
3.39
3.40
3.41
3.42
3.综合应用
3.1
import java.text.DecimalFormat;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
//*********Found********
public class Java_3 extends JFrame implements ActionListener {
private JTextField input1, input2, output;
private int number1, number2;
private double result;
// 初始化
public Java_3()
{
//*********Found********
super( "示范异常" );
Container c = getContentPane();
c.setLayout( new GridLayout( 3, 2 ) );
c.add( new JLabel( "输入分子",
SwingConstants.RIGHT ) );
input1 = new JTextField( 10 );
c.add( input1 );
c.add(
new JLabel( "输入分母和回车",
SwingConstants.RIGHT ) );
input2 = new JTextField( 10 );
c.add( input2 );
input2.addActionListener( this );
c.add( new JLabel( "计算结果", SwingConstants.RIGHT ) );
output = new JTextField();
c.add( output );
setSize( 425, 100 );
show();
}
//处理 GUI 事件
public void actionPerformed( ActionEvent e )
{
DecimalFormat precision3 = new DecimalFormat( "0.000" );
output.setText( "" ); // 空的JTextField输出
//*********Found********
try{
number1 = Integer.parseInt( input1.getText() );
number2 = Integer.parseInt( input2.getText() );
result = quotient( number1, number2 );
//*********Found********
output.setText(precision3.format(result));
}
catch ( NumberFormatException nfe ) {
JOptionPane.showMessageDialog( this,
"你必须输入两个整数",
"非法数字格式",
JOptionPane.ERROR_MESSAGE );
}
catch ( Exception dbze ) {
//*********Found********
JOptionPane.showMessageDialog( this,
"除法异常",
"除数为零",
JOptionPane.ERROR_MESSAGE );
}
}
// 定义求商的方法，如遇除数为零时，能抛出异常。
public double quotient( int numerator, int denominator )
throws Exception
{
if ( denominator == 0 )
throw new Exception();
return ( double ) numerator / denominator;
}
public static void main( String args[] )
{
Java_3 app = new Java_3();
app.addWindowListener(
new WindowAdapter() {
public void windowClosing( WindowEvent e )
{
e.getWindow().dispose();
System.exit( 0 );
}
}
);
}
}
/* JOptionPane类的常用静态方法如下：
showInputDialog()
showConfirmDialog()
showMessageDialog()
showOptionDialog()
*/
3.2
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 extends JFrame
{
public FontFrame()
{
setTitle("沁园春.雪");
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
FontPanel panel = new FontPanel();
Container contentPane = getContentPane();
//*********Found********
contentPane.add(panel);
}
public static final int DEFAULT_WIDTH = 300;
public static final int DEFAULT_HEIGHT = 200;
}
//*********Found********
class FontPanel extends JPanel
{
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", Font.BOLD, 24);
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.drawString(message, (int)x, (int)(baseY));
}
}
3.3
public class Java_3{
public static void main(String[] args) {
String text = "Beijing, the Capital City, is the political,"
+ "cultural and diplomatic centre of China. It has"
+ "become a modern international cosmopolitan city"
+ "with more than 11 million people. The Capital"
+ "International Airport, 23.5 km from the city centre,"
+ "is China's largest and most advanced airport.";
int vowels = 0 ;
//*********Found*********
int textLength= text.length();
for(int i = 0; i < textLength; i++) {
//*********Found*********
char ch = Character.toLowerCase(text.charAt(i));
if(ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u') {
//*********Found*********
vowels++;
}
}
System.out.println("The text contained vowels: " + vowels + "\n" );
}
}
3.4
import java.awt.*;
import javax.swing.*;
public class Java_3{
public static void main(String[] args){
BeijingFrame frame = new BeijingFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.show();
}
}
//*********Found*********
class BeijingFrame extends JFrame{
public BeijingFrame(){
setTitle("Welcome to Beijing");
Container contentPane = getContentPane();
BeijingPanel panel = new BeijingPanel();
contentPane.add(panel);
pack();
}
}
class BeijingPanel extends JPanel{
public BeijingPanel(){
//*********Found*********
setLayout(new BorderLayout() );
ImageIcon icon = new ImageIcon("tiantan.jpg");
//*********Found*********
jLC = new JLabel( icon );
add(jLC, BorderLayout.CENTER);
lpanel = new JPanel();
jLS = new JLabel("The Temple of Heaven");
lpanel.add(jLS);
add(lpanel, BorderLayout.SOUTH);
}
private JLabel jLC;
private JLabel jLS;
private JPanel panel;
private JPanel lpanel;
}
3.5
//*********Found**********
import javax.swing.JFrame;
import java.awt.*;
public class Java_3{
static final int WIDTH=300;
static final int HEIGHT=200;
public static void main(String[] args){
//*********Found**********
JFrame jf=new JFrame();
jf.setSize(WIDTH,HEIGHT);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//*********Found**********
jf.setTitle("股票分析系统");
Toolkit kit=Toolkit.getDefaultToolkit();
Dimension screenSize=kit.getScreenSize();
int width=screenSize.width;
int height=screenSize.height;
int x=(width-WIDTH)/2;
int y=(height-HEIGHT)/2;
jf.setLocation (x,y);
//*********Found**********
jf.setVisible(true);
}
}
3.6（*）
import java.io.*;
public class Java_3{
public static int data[]={32,18,41,23,2,56,36,67,59,20};
public static void main(String args[]){
int i;
//*********Found**********
int index=data.length;
System.out.println("排序前:");
for(i=0;i<index;i++)
System.out.print(" "+data[i]+" ");
System.out.println();
//*********Found**********
BubbleSort( index );
System.out.println("排序后:");
for(i=0;i<index;i++)
System.out.print(" "+data[i]+" ");
System.out.println();
}
// 冒泡法排序
public static void BubbleSort(int index){
int i,j;
int temp;
for(j=1;j<index;j++){
for(i=index-1;i>=j;i--){
if(data[i]<data[i-1]){ //比较相邻的两个数
temp=data[i];
data[i]=data[i-1];
//*********Found**********
data[i-1]= temp ;
}
}
}
}
}
3.7
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Java_3{
public static void main(String[] args){
MulticastFrame frame = new MulticastFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.show();
}
}
class MulticastFrame extends JFrame{
public MulticastFrame(){
setTitle("MulticastTest");
setSize(WIDTH, HEIGHT);
MulticastPanel panel = new MulticastPanel();
Container contentPane = getContentPane();
//*********Found**********
contentPane.add(panel);
}
public static final int WIDTH = 300;
public static final int HEIGHT = 200;
}
class MulticastPanel extends JPanel{
public MulticastPanel(){
JButton newButton = new JButton("New");
add(newButton);
ActionListener newListener = new ActionListener(){
public void actionPerformed(ActionEvent event){
makeNewFrame();
}
};
newButton.addActionListener(newListener);
closeAllButton = new JButton("Close all");
add(closeAllButton);
}
private void makeNewFrame(){
final BlankFrame frame = new BlankFrame();
frame.show();
ActionListener closeAllListener = new ActionListener(){
public void actionPerformed(ActionEvent event){
//*********Found**********
frame.dispose(); //使窗口隐藏或消除
}
};
//*********Found**********
closeAllButton.addActionListener(closeAllListener);
}
private JButton closeAllButton;
}
class BlankFrame extends JFrame{
public BlankFrame(){
//*********Found**********
counter++ ;
setTitle("Frame " + counter);
setSize(WIDTH, HEIGHT);
setLocation(SPACING * counter, SPACING * counter);
}
public static final int WIDTH = 200;
public static final int HEIGHT = 150;
public static final int SPACING = 30;
private static int counter = 0;
}
3.8
import javax.swing.*;
import java.awt.event.*;
import java.io.*;
import java.awt.*;
//*********Found**********
public class Java_3 implements ActionListener{
JFrame f;
JTextArea ta;
JFileChooser fc;
Container c;
File myFile;
public static void main(String args[]){
Java_3 demo=new Java_3();
demo.go();
}
void go(){
JFrame f=new JFrame("File Chooser Demo");
JButton b=new JButton("Open file");
ta=new JTextArea("Where is your file path?",10,30);
//*********Found**********
b.addActionListener(this);
c=f.getContentPane();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.getContentPane().add("South",b);
f.getContentPane().add("Center",ta);
f.setSize(300,300);
f.setVisible(true);
}
public void actionPerformed(ActionEvent e){
fc=new JFileChooser();
//*********Found**********
int selected=fc.showOpenDialog(c);
if (selected==JFileChooser.APPROVE_OPTION){
myFile=fc.getSelectedFile();
//*********Found**********
ta.setText("You have selected file: "+myFile.getName());
}
}
}
3.9
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
//*********Found**********
public class Java_3 extends WindowAdapter implements ActionListener
{
private JFrame frame;
private JTextField name;
private JPasswordField pass;
private JLabel nameLabel;
private JLabel passLabel;
private JPanel textPanel;
private JPanel labelPanel;
private JButton button;
private JTextArea textArea;
public void initGUI()
{
frame=new JFrame("Frame with Dialog");
frame.addWindowListener(this);
button=new JButton("JDialog");
//*********Found**********
button.addActionListener(this);
textArea=new JTextArea("",3,10);
frame.getContentPane().add(textArea,BorderLayout.CENTER);
frame.getContentPane().add(button,BorderLayout.NORTH);
frame.setSize(400,300);
frame.setVisible(true);
}
public void actionPerformed(ActionEvent e)
{
final JDialog dia=new JDialog(frame,"login information");
JButton ok=new JButton("ok");
ok.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
textArea.setText("");
textArea.append("name:"+name.getText()+"\r\n");
textArea.append("passWord:"+new String(pass.getPassword())+"\r\n");
//*********Found**********
dia.setVisible(false); //隐藏对话框
}
});
name=new JTextField("",10);
pass=new JPasswordField("",10);
pass.setEchoChar('*');
textPanel=new JPanel();
textPanel.setLayout(new GridLayout(2,1,10,10));
textPanel.add(name);
textPanel.add(pass);
nameLabel=new JLabel("name");
passLabel=new JLabel("passWord");
labelPanel=new JPanel();
labelPanel.setLayout(new GridLayout(2,1,20,20));
labelPanel.add(nameLabel);
labelPanel.add(passLabel);
dia.getContentPane().add(labelPanel,BorderLayout.WEST);
dia.getContentPane().add(textPanel,BorderLayout.CENTER);
dia.getContentPane().add(ok,BorderLayout.SOUTH);
dia.setSize(200,130);
dia.setVisible(true);
}
public void windowClosing(WindowEvent event)
{
frame.setVisible(false);
System.exit(0);
}
public static void main(String args[])
{
Java_3 example=new Java_3();
//*********Found**********
example.initGUI();
}
}
3.10
import java.awt.*;
import java.awt.event.*;
//*********Found**********
import javax.swing.*;
public class Java_3 {
public static void main(String[ ] args) {
JFrame frame = new JFrame("Demo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//*********Found**********
frame.getContentPane().add(new Change());
frame.pack();
frame.setVisible(true);
}
}
class Change extends JPanel {
int count = 200;
JLabel l1;
JButton b1, b2;
public Change( ) {
setPreferredSize(new Dimension(280, 60));
l1 = new JLabel("200");
b1 = new JButton("增大");
b2 = new JButton("减小");
add(l1);
//*********Found**********
add(b1);
//*********Found**********
add(b2);
b1.addActionListener( new BListener( ) );
b2.addActionListener( new BListener( ) );
}
//*********Found**********
private class BListener implements ActionListener {
//*********Found**********
public void actionPerformed(ActionEvent e) {
if (e.getSource( ) == b1) {
count++;
} else {
count--;
}
l1.setText("" + count);
}
}
}
3.11
import java.awt.*;
import java.awt.event.*;
//*********Found**********
import javax.swing.*;
//*********Found**********
public class Java_3 extends JPanel{
private int counter = 0;
private JButton closeAllButton;
public Java_3() {
JButton newButton = new JButton("New");
//*********Found**********
add(newButton);
newButton.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent evt){
CloseFrame f = new CloseFrame();
counter++;
f.setTitle("窗体 " + counter);
f.setSize(200, 150);
f.setLocation(30 * counter, 30 * counter);
//*********Found**********
f.setVisible(true);
closeAllButton.addActionListener(f);
}
});
closeAllButton = new JButton("Close all");
add(closeAllButton);
}
public static void main(String[ ] args) {
JFrame frame = new JFrame();
frame.setTitle("多窗体测试");
frame.setSize(300, 200);
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
Container contentPane = frame.getContentPane();
contentPane.add(new Java_3());
frame.setVisible(true) ;
}
}
//*********Found**********
class CloseFrame extends JFrame implements ActionListener {
public void actionPerformed(ActionEvent evt) {
setVisible(false);
}
}
3.12
import java.io.*;
import java.awt.event.* ;
import javax.swing.*;
public class Java_3 implements ActionListener{
public static void main(String args[]){
Java_3 t = new Java_3();
//*********Found**********
JFrame f = new JFrame("Test");
JButton b = new JButton("复制文件");
b.setSize(100,40);
b.addActionListener(t);
f.setSize(400,400);
//*********Found**********
f.getContentPane().add(b);
f.pack();
f.setVisible(true) ;
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void actionPerformed(ActionEvent event){
try{
//*********Found**********
FileInputStream in=new FileInputStream("a.txt");
//*********Found**********
FileOutputStream out=new FileOutputStream("b.txt");
int c;
while ((c = in.read()) != -1)
out.write(c);
in.close();
out.close();
} catch( Exception e){
}
}
}
3.13
//*********Found**********
import javax.swing.*;
import java.awt.event.*;
import java.io.*;
import java.awt.*;
//*********Found**********
public class Java_3 implements ActionListener {
JFrame f;
JPanel p;
JColorChooser cc;
Container c;
Color myColor;
JMenuBar mb;
JMenu m1;
JMenuItem mi1;
public static void main(String args[]) {
Java_3 demo = new Java_3();
demo.go();
}
void go() {
JFrame f = new JFrame("File Chooser Demo");
mb = new JMenuBar();
f.setJMenuBar(mb);
m1 = new JMenu("Edit");
mb.add(m1);
mi1 = new JMenuItem("Choose Color");
m1.add(mi1);
mi1.addActionListener(this);
//*********Found**********
c =f .getContentPane();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
p = new JPanel();
myColor = Color.red;
p.setBackground(myColor);
c.add("Center", p);
f.setSize(300, 300);
//*********Found**********
f.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
//*********Found**********
cc = new JColorChooser();
myColor = cc.showDialog(c, "Choose window background color", Color.white);
p.setBackground(myColor);
}
}
3.14
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Java_3 {
public static void main(String[ ] args) {
JFrame frame = new JFrame("Demo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//*********Found**********
frame.getContentPane().add(new Change());
frame.pack();
//*********Found**********
frame.setVisible(true);
}
}
class Change extends JPanel{
int count = 200;
JLabel l1;
JButton b1, b2;
public Change() {
setPreferredSize(new Dimension(280, 60));
l1 = new JLabel("200");
b1 = new JButton("增大");
b2 = new JButton("减小");
add(l1);
add(b1);
add(b2);
b1.addActionListener(new BListener1());
//*********Found**********
b2.addActionListener(new BListener2());
}
private class BListener1 implements ActionListener {
public void actionPerformed(ActionEvent e) {
count++;
l1.setText("" + count);
}
}
private class BListener2 implements ActionListener {
public void actionPerformed(ActionEvent e) {
//*********Found**********
count --;
l1.setText("" + count);
}
}
}
3.15
import javax.swing.*;
import java.awt.event.*;
import java.io.*;
import java.awt.*;
//*********Found**********
public class Java_3 implements ActionListener{
JFrame f;
JPanel p;
JColorChooser cc;
Container c;
Color myColor;
JMenuBar mb;
JMenu m1;
JMenuItem mi1;
public static void main(String args[]){
Java_3 demo=new Java_3();
demo.go();
}
void go(){
JFrame f=new JFrame("File Chooser Demo");
mb=new JMenuBar();
f.setJMenuBar(mb);
//*********Found**********
m1=new JMenu("Edit");
mb.add(m1);
mi1=new JMenuItem("Choose Color");
m1.add(mi1);
//*********Found**********
mi1.addActionListener(this);
c=f.getContentPane();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
p=new JPanel();
myColor=Color.red;
p.setBackground(myColor);
c.add("Center",p);
f.setSize(300,300);
f.setVisible(true);
}
public void actionPerformed(ActionEvent e){
cc=new JColorChooser();
//*********Found**********
myColor=cc.showDialog(c,"Choose window background color",Color.white);
p.setBackground(myColor);
}
}
3.16
import javax.swing.*;
//*********Found********
import java.awt.event.*;
import java.io.*;
import java.awt.*;
//*********Found********
public class Java_3 implements ActionListener{
JFrame f;
JTextArea ta;
//*********Found********
JFileChooser fc;
Container c;
File myFile;
public static void main(String args[]){
Java_3 demo = new Java_3();
demo.go();
}
void go(){
f = new JFrame("File Chooser Demo");
//*********Found********
JButton b = new JButton("Open file");
ta = new JTextArea("Where is your file path?",10,30);
//*********Found********
b.addActionListener(this);
c = f.getContentPane();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//*********Found********
f.getContentPane().add("South", b);
f.getContentPane().add("Center",ta);
f.setSize(300,300);
f.setVisible(true);
}
public void actionPerformed(ActionEvent e){
fc = new JFileChooser();
int selected = fc.showOpenDialog(c);
if (selected==JFileChooser.APPROVE_OPTION){
myFile = fc.getSelectedFile();
ta.setText("You have selected file: "+ myFile.getName());
}
}
}
3.17
//*********Found********
public class Java_3 extends Thread{
static RegistrationAgent agent;
static boolean timetoquit=false;
public static void main(String[] args){
agent = new RegistrationAgent();
Thread[] t= new Thread[3];
for (int i=0; i<3; i++){
t[i] = new Java_3();
//*********Found********
t[i].start();
}
}
public void run( ){
//*********Found********
while (!timetoquit){
boolean r = agent.reg();
if (!r)
timetoquit = true;
try{
Thread.sleep(2);
}catch(Exception e){}
}
}
}
class RegistrationAgent {
private int quota = 0;
public boolean reg(){
synchronized(this){
if( quota < 10){
//*********Found********
quota++;
System.out.print(Thread.currentThread().getName());
System.out.println( " Registered one student, and total " + quota
+" students registered.");
return true;
}
else
//*********Found********
return false;
}
}
}
3.18
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.imageio.*;
import javax.swing.*;
public class Java_3 extends JFrame {
private JLabel label;
private JFileChooser fileChooser;
private ImagePanel panel;
public Java_3() {
setTitle("图片浏览器");
setSize(500, 400);
fileChooser = new JFileChooser();
fileChooser.setCurrentDirectory(new File("."));//设置默认路径为当前目录
JMenuBar menuBar = new JMenuBar();
setJMenuBar(menuBar);
JMenu menu = new JMenu("文件");
menuBar.add(menu);
JMenuItem openItem = new JMenuItem("打开图片");
menu.add(openItem);
panel = new ImagePanel();
add(panel);
//*********Found********
openItem.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent event){
int result = fileChooser.showOpenDialog(null);
if(result==JFileChooser.APPROVE_OPTION){
String name = fileChooser.getSelectedFile().getPath();
//*********Found********
panel.setImage(name);
panel.repaint();
}
}
});
JMenuItem exitItem = new JMenuItem("退出图片");
menu.add(exitItem);
exitItem.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent event){
System.exit(0);
}
});
}
public static void main(String[] args) {
//*********Found********
Java_3 frame = new Java_3 ();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//*********Found********
frame.setVisible(true);
}
}
//*********Found********
class ImagePanel extends JPanel {
private Image image;
private int showWidth;
private int showHeight;
public void setImage(String fileName) {
try {
image = ImageIO.read(new File(fileName));
} catch (IOException e) {
e.printStackTrace();
}
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
if (image == null)
return;
int imageWidth = image.getWidth(this);
int imageHeight = image.getHeight(this);
int width = getWidth();
int height = getHeight();
if(imageWidth>width){
this.showWidth = width;
}else{
this.showWidth = imageWidth;
}
if(imageHeight>height){
this.showHeight = height;
}else{
this.showHeight = imageHeight;
}
g.drawImage(image, 0, 0, showWidth, showHeight, null, null);
}
}
3.19
import java.io.*;
import java.lang.Thread;
class MyThread extends Thread{
public int x = 0;
//*********Found********
public void run(){
System.out.println(++x);
}
}
//*********Found********
class RThread implements Runnable{
private int x = 0;
public void run(){
System.out.println(++x);
}
}
public class Java_3 {
public static void main(String[] args) throws Exception{
for(int i=0;i<5;i++){
Thread t = new MyThread();
//*********Found********
t.start();
}
Thread.sleep(1000);
System.out.println();
//*********Found********
RThread r = new RThread();
//*********Found********
for(int i=0;i<5;i++){
Thread t = new Thread(r);
t.start();
}
}
}
3.20
//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() {
//*********Found********
public void actionPerformed( ActionEvent e ){
int val = Integer.parseInt(
e.getActionCommand() );
//*********Found********
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 );
setVisible(true);
}
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 );
}
}
);
}
}
3.21
import java.io.*;
public class Java_3
{
public static void main(String[] args)
{
Java_3 exceptionExample = new Java_3();
//*********Found**********
try
{
FileInputStream fi = new FileInputStream("C:" + "\\" + "abc.txt");
}
//*********Found**********
catch(FileNotFoundException ex)
{
//*********Found**********
System.out.println(ex.getMessage()+
"请确认文件路径及文件名是否正确！");
}
}
}
3.22
import java.awt.*;
import javax.swing.*;
//*********Found**********
public class Java_3 extends JApplet
{
//*********Found**********
public void init()
{
Container contentPane = getContentPane();
JLabel label = new JLabel("One World One Dream",SwingConstants.CENTER);
label.setFont(new Font("Arial", Font.BOLD, DEFAULT_SIZE));
//*********Found**********
contentPane.add(label);
}
private static final int DEFAULT_SIZE = 24;
}
3.23
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.swing.*;
public class Java_3
{
public static void main(String[] args)
{
JFrame frame = new ImageViewerFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//*********Found**********
frame.setVisible(true);
}
}
class ImageViewerFrame extends JFrame
{
private JLabel label;
private JLabel labelT;
private JFileChooser chooser;
private JComboBox faceCombo;
private static final int DEFAULT_SIZE = 24;
public static final int DEFAULT_WIDTH = 570;
public static final int DEFAULT_HEIGHT = 400;
public ImageViewerFrame()
{
setTitle("ImageViewer");
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
label = new JLabel();
Container contentPane = getContentPane();
contentPane.add(label,BorderLayout.CENTER);
chooser = new JFileChooser();
chooser.setCurrentDirectory(new File("."));
JMenuBar menuBar = new JMenuBar();
setJMenuBar(menuBar);
//*********Found**********
JMenu menu = new JMenu("File");
menuBar.add(menu);
JMenuItem openItem = new JMenuItem("Open");
//*********Found**********
menu.add(openItem);
openItem.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent evt)
{
int r = chooser.showOpenDialog(null);
if(r == JFileChooser.APPROVE_OPTION)
{
//*********Found**********
String name = chooser.getSelectedFile().getPath();
label.setIcon(new ImageIcon(name));
}
}
});
labelT = new JLabel("红军不怕远征难");
labelT.setFont(new Font("隶书", Font.PLAIN, DEFAULT_SIZE));
contentPane.add(labelT, BorderLayout.NORTH );
faceCombo = new JComboBox();
faceCombo.setEditable(true);
faceCombo.addItem("隶书");
faceCombo.addItem("华文新魏");
faceCombo.addItem("华文行楷");
faceCombo.addItem("华文隶书");
faceCombo.addActionListener(new
ActionListener()
{
public void actionPerformed(ActionEvent event)
{
//*********Found**********
labelT.setFont(new Font((String)faceCombo.getSelectedItem(),
Font.PLAIN, DEFAULT_SIZE));
}
});
JPanel comboPanel = new JPanel();
comboPanel.add(faceCombo);
contentPane.add(comboPanel, BorderLayout.SOUTH);
}
}
3.24
import java.awt.event.*;
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 extends JFrame
{
public FontFrame()
{
setTitle("北京 2008");
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
FontPanel panel = new FontPanel();
Container contentPane = getContentPane();
//*********Found**********
contentPane.add(panel);
}
public static final int DEFAULT_WIDTH = 400;
public static final int DEFAULT_HEIGHT = 250;
}
class FontPanel extends JPanel
{
public FontPanel()
{
JButton yellowButton = new JButton("Yellow");
JButton blueButton = new JButton("Blue");
JButton redButton = new JButton("Green");
add(yellowButton);
add(blueButton);
add(redButton);
ColorAction yellowAction = new ColorAction(Color.YELLOW);
ColorAction blueAction = new ColorAction(Color.BLUE);
ColorAction greenAction = new ColorAction(Color.GREEN);
yellowButton.addActionListener(yellowAction);
blueButton.addActionListener(blueAction);
redButton.addActionListener(greenAction);
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
String message = "同一个世界，同一个梦想！";
Font f = new Font("隶书", Font.BOLD, 27);
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);
g2.drawString (message, (int)x, (int)(baseY));
}
//*********Found**********
private class ColorAction implements ActionListener
{
public ColorAction(Color c)
{
BackgroundColor = c;
}
//*********Found**********
public void actionPerformed(ActionEvent event)
{
setBackground(BackgroundColor);
}
private Color BackgroundColor;
}
}
3.25
import javax.swing.*;
import java.awt.event.*;
import java.io.*;
import java.awt.*;
public class Java_3 implements ActionListener
{
private JFrame frame;
private JButton button;
private JButton saveButton;
private JTextArea textArea;
private JFileChooser dia;
private JPanel buttonPanel;
public void initGUI()
{
//*********Found**********
frame=new JFrame("file chooser");
button=new JButton("open file");
button.setActionCommand("open");
//*********Found**********
button.addActionListener(this);
saveButton=new JButton("save file");
saveButton.setActionCommand("save");
//*********Found**********
saveButton.addActionListener(this);
textArea=new JTextArea("",10,10);
buttonPanel=new JPanel();
dia=new JFileChooser();
frame.addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
buttonPanel.add(button);
buttonPanel.add(saveButton);
frame.getContentPane().add(buttonPanel,BorderLayout.NORTH);
frame.getContentPane().add(textArea,BorderLayout.CENTER);
frame.setSize(300,300);
//*********Found**********
frame.setVisible(true);
}
//*********Found**********
public void actionPerformed(ActionEvent event)
{
if(event.getActionCommand().equals("open"))
{
dia.showOpenDialog( frame );
dia.setVisible(true);
File file=dia.getSelectedFile();
String fileName=file.getAbsolutePath();
textArea.append("path of selected file: "+fileName+"\r\n");
}
else if(event.getActionCommand().equals("save"))
{
dia.showSaveDialog(frame);
dia.setVisible(true);
File file=dia.getSelectedFile();
String fileName=file.getAbsolutePath();
textArea.append("path of saved file: "+fileName+"\r\n");
}
}
public static void main(String args[])
{
Java_3 example=new Java_3();
example.initGUI();
}
}
3.26
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
//*********Found**********
public class Java_3 extends MouseAdapter implements ActionListener
{
//*********Found**********
private JPopupMenu pop;
private JMenu subPop;
private JMenuItem color;
private JMenuItem exit;
private JMenuItem red;
private JMenuItem blue;
private JTextArea textArea;
private JFrame frame;
public void initGUI()
{
pop=new JPopupMenu();
subPop=new JMenu("color");
//*********Found**********
red=new JMenuItem("red");
red.addActionListener(this);
blue=new JMenuItem("blue");
blue.addActionListener(this);
subPop.add(red);
subPop.add(blue);
exit=new JMenuItem("exit");
exit.addActionListener(this);
pop.add(subPop);
pop.add(exit);
frame=new JFrame("popup frame");
textArea=new JTextArea("",10,10);
textArea.addMouseListener(this);
//*********Found**********
frame.getContentPane().add(textArea);
frame.setSize(300,300);
frame.setVisible(true);
frame.addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
}
public void actionPerformed(ActionEvent event)
{
if(event.getSource()==red)
{
//*********Found**********
textArea.setForeground(Color.red);
textArea.setText("red menu is selected");
}
else if(event.getSource()==blue)
{
textArea.setForeground(Color.blue);
textArea.setText("blue menu is selected");
}
else if(event.getSource()==exit)
{
frame.setVisible(false);
System.exit(0);
}
}
public void mousePressed(MouseEvent e)
{
if(e.getModifiers()==e.BUTTON3_MASK)
{
pop.show(e.getComponent(),e.getX(),e.getY());
}
}
public static void main(String args[])
{
Java_3 example=new Java_3();
example.initGUI();
}
}
3.27
import java.awt.Graphics;
import javax.swing.JApplet;
//*********Found**********
public class Java_3 extends JApplet {
//*********Found**********
public void paint(Graphics g){
int counter = 1;
do {
//*********Found**********
g.drawOval( 110 - counter * 10, 110 - counter * 10,
counter * 20, counter * 20 );
//*********Found**********
counter++;
} while (counter<=10);
}
}
3.28
//*********Found**********
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
//*********Found**********
public class Java_3 extends MouseAdapter implements ActionListener
{
//*********Found**********
private JPopupMenu pop;
private JMenu subPop;
private JMenuItem color;
private JMenuItem exit;
private JMenuItem red;
private JMenuItem blue;
private JTextArea textArea;
private JFrame frame;
public void initGUI()
{
pop=new JPopupMenu();
subPop=new JMenu("color");
red=new JMenuItem("red");
red.addActionListener(this);
blue=new JMenuItem("blue");
blue.addActionListener(this);
subPop.add(red);
subPop.add(blue);
exit=new JMenuItem("exit");
exit.addActionListener(this);
pop.add(subPop);
pop.add(exit);
//*********Found**********
frame=new JFrame("popupframe");
textArea=new JTextArea("",10,10);
textArea.addMouseListener(this);
frame.getContentPane().add(textArea);
frame.setSize(300,300);
frame.setVisible(true);
frame.addWindowListener(new WindowAdapter()
{
//*********Found**********
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
}
public void actionPerformed(ActionEvent event)
{
if(event.getSource()==red)
{
textArea.setForeground(Color.red);
textArea.setText("red menu is selected");
}
else if(event.getSource()==blue)
{
textArea.setForeground(Color.blue);
textArea.setText("blue menu is selected");
}
else if(event.getSource()==exit)
{
frame.setVisible(false);
System.exit(0);
}
}
public void mousePressed(MouseEvent e)
{
if(e.getModifiers()==e.BUTTON3_MASK)
{
pop.show(e.getComponent(),e.getX(),e.getY());
}
}
public static void main(String args[])
{
Java_3 example=new Java_3();
example.initGUI();
}
}
3.29
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();
//*********Found********
contentPane.add(panel);
pack();
}
}
class ExceptTestPanel extends Box
{
public ExceptTestPanel()
{
super(BoxLayout.Y_AXIS);
group = new ButtonGroup();
addRadioButton("整数被零除", new
ActionListener()
{
//*********Found********
public void actionPerformed(ActionEvent event)
{
a[1] = 1 / (a.length - a.length);
}
});
textField = new JTextField(30);
add(textField);
}
//*********Found********
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.setText(exception.toString());
}
}
};
button.addActionListener(listener);
add(button);
group.add(button);
}
private ButtonGroup group;
private JTextField textField;
private double[] a = new double[10];
}
3.30
import java.awt.*;
import javax.swing.*;
//*********Found**********
public class Java_3 extends JApplet{
//*********Found**********
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);
//*********Found**********
contentPane.add(label);
}
}
3.31
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
//*********Found********
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( firstNumber );
//*********Found********
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",
JOptionPane.INFORMATION_MESSAGE);
//*********Found********
System.exit( 0 );
}
}
3.32
import java.awt.Graphics;
import javax.swing.*;
//*********Found**********
public class Java_3 extends JApplet{
double sum; //存和的变量
//*********Found**********
public void init(){
String firstNumber, //输入第1个字符串格式的数
secondNumber; //输入第2个字符串格式的数
double number1, //加数
number2; //被加数
//读入第1个输入的数
firstNumber =
JOptionPane.showInputDialog(
"Enter first floating-point value" );
//读入第2个输入的数
secondNumber =
JOptionPane.showInputDialog(
"Enter second floating-point value" );
//将字符串数据转换成双字长类型
number1 = Double.parseDouble( firstNumber );
number2 = Double.parseDouble( secondNumber );
//数据相加
sum = number1 + number2;
}
public void paint( Graphics g ) {
//用g.drawString给结果
g.drawRect( 15, 10, 270, 20 );
g.drawString( "数相加之和为:" + sum, 25, 25 );
}
}
<html>
//*********Found**********
<applet code="Java_3.class" width=300 height=50>
</applet>
</html>
3.33
import java.awt.*;
import javax.swing.*;
//*********Found**********
public class Java_3 extends JApplet{
JTextArea outputArea;
public void init(){
outputArea = new JTextArea();
//*********Found**********
Container c = getContentPane();
//*********Found**********
c.add( outputArea );
//计算0至10的阶乘
for ( long i = 0; i <= 10; i++ )
outputArea.append(
i + "! = " + factorial( i ) + "\n" );
}
//阶乘的递归定义
public long factorial( long number ){
if ( number <= 1 )
return 1;
else
return number * factorial( number - 1 );
}
}
3.34
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
//*********Found**********
public class Java_3 extends JApplet implements ActionListener{
JLabel prompt;
JTextField input;
public void init(){
Container c = getContentPane();
c.setLayout( new FlowLayout() );
//*********Found**********
prompt = new JLabel( "输入球半径: " );
input = new JTextField( 10 );
//*********Found**********
input.addActionListener(this);
c.add( prompt );
c.add( input );
}
public void actionPerformed( ActionEvent e ){
double radius =
Double.parseDouble( e.getActionCommand() );
showStatus( "体积 " + sphereVolume( radius ) );
}
public double sphereVolume( double radius ){
double volume =
( 4.0 / 3.0 ) * Math.PI * Math.pow( radius, 3 );
return volume;
}
}
3.35
import java.lang.*;
import java.util.*;
public class Java_3{
public static void main(String[ ]args){
int bound=100;
int i=0,j=0,counter=0,k=0;
int temp=0;
boolean first=true;
for(i=1;i<bound;i++){
for(j=1;j<bound;j++){
//*********Found**********
temp=i*i +5*j*j;
k=(int)Math.sqrt(temp);
//*********Found**********
if(k<bound && k*k == temp ){
if(first){
System.out.println("The first component: ("+i+", "+j+", "+k+")");
//*********Found**********
first=false;
}
//*********Found**********
counter++;
}
};
}
System.out.print("Total number is: "+counter);
System.exit(0);
}
}
3.36
import java.lang.*;
import java.util.*;
public class Java_3{
public static void main(String[ ]args){
int bound=100;
int i=0,j=0,counter=0,k=0;
int temp=0;
boolean first=true;
for(i=1;i<bound;i++){
for(j=1;j<bound;j++){
//*********Found**********
temp=i*i +5*j*j;
k=(int)Math.sqrt(temp);
//*********Found**********
if(k<bound && k*k == temp ){
if(first){
System.out.println("The first component: ("+i+", "+j+", "+k+")");
//*********Found**********
first=false;
}
//*********Found**********
counter++;
}
};
}
System.out.print("Total number is: "+counter);
System.exit(0);
}
}
3.37
import java.awt.*;
import java.awt.event.* ;
//*********Found********
import javax.swing.*;
//*********Found********
public class Java_3 implements ActionListener{
public static void main(String args[ ]){
Java_3 tb = new Java_3();
//*********Found********
JFrame f = new JFrame("Button Test");
f.setSize(200,100);
f.setLayout(new FlowLayout(FlowLayout.CENTER));
JButton b = new JButton("Press the Button!"); /JButton
//*********Found********
b.addActionListener(tb);
//*********Found********
f.add(b);
f.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
System.exit(0);
}
});
f.setVisible(true) ;
}
//*********Found********
public void actionPerformed(ActionEvent e){
JFrame fr = new JFrame("An Other");
fr.setBackground(Color.green);
fr.add(new JLabel("This frame shows when "+"pressing the button in Button Test"));
fr.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
System.exit(0);
}
});
fr.pack();
fr.setVisible(true) ;
}
}
3.38
import java.io.*;
import java.util.*;
public class Java_3
{
//*********Found**********
public static void main (String args[]) throws IOException {
FileOutputStream unbufStream = new FileOutputStream("test.one");
BufferedOutputStream bufStream = new BufferedOutputStream(
//*********Found**********
new FileOutputStream ("test.two"));
System.out.println();
System.out.println("这是一个测试缓冲流和非缓冲流速度的程序。");
System.out.println();
//*********Found**********
int flag = time(unbufStream)-time(bufStream);
if(flag > 0) {
System.out.println("测试结果：缓冲流的传输速度快于非缓冲流。");
System.out.println();
}
else
System.out.println("测试结果：缓冲流的传输速度慢于非缓冲流。");
}
//*********Found**********
static int time(OutputStream out) throws IOException {
//*********Found**********
Date then = new Date();
for (int i=0; i<1000; i++) {
out.write(1);
}
//*********Found**********
out.close ();
return (int)((new Date()).getTime() - then.getTime());
}
}
3.39
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
//**********found**********
public class Java_3 extends JFrame {
private JTextField username;
private JPasswordField password;
private JLabel jl1;
private JLabel jl2;
private JLabel jl3;
private JLabel jl4;
private JButton bu1;
private JButton bu2;
private JButton bu3;
private JCheckBox jc1;
private JCheckBox jc2;
private JComboBox jcb;
public Java_3() {
this.setTitle("QQ2022正式版");
init();
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// 设置布局方式为绝对定位
this.setLayout(null);
this.setBounds(0, 0, 355, 265);
// 设置窗体的标题图标
Image image = new ImageIcon("a.png").getImage();
this.setIconImage(image);
// 窗体大小不能改变
this.setResizable(false);
// 居中显示
this.setLocationRelativeTo(null);
//**********found**********
this.setVisible(true);
}
public void init() {
Container con = this.getContentPane();
jl1 = new JLabel();
// 设置背景图片
Image image1 = new ImageIcon("background.jpg").getImage();
jl1.setIcon(new ImageIcon(image1));
jl1.setBounds(0, 0, 355, 265);
jl2 = new JLabel();
Image image2 = new ImageIcon("a.gif").getImage();
jl2.setIcon(new ImageIcon(image2));
jl2.setBounds(40, 95, 50, 60);
//**********found**********
username = new JTextField();
username.setBounds(50, 50, 150, 20);
jl3 = new JLabel("注册账号");
jl3.setBounds(210, 50, 70, 20);
password = new JPasswordField();
password.setBounds(50, 80, 150, 20);
jl4 = new JLabel("找回密码");
jl4.setBounds(210, 80, 70, 20);
jc1 = new JCheckBox("记住密码");
jc1.setBounds(125, 135, 80, 15);
jc2 = new JCheckBox("自动登录");
jc2.setBounds(215, 135, 80, 15);
jcb = new JComboBox();
jcb.addItem("在线");
jcb.addItem("隐身");
jcb.addItem("离开");
jcb.setBounds(40, 135, 55, 20);
bu1 = new JButton("登录");
bu1.setBounds(250, 200, 65, 20);
bu2 = new JButton("多账号");
bu2.setBounds(25, 200, 75, 20);
bu3 = new JButton("设置");
bu3.setBounds(140, 200, 65, 20);
bu3.addActionListener(new ActionListener() {
//**********found**********
public void actionPerformed(ActionEvent e) {
if (jc1.isSelected()==true)
JOptionPane.showConfirmDialog(null,"确定记住密码吗?");
}
});
// 所有组件用容器装载
jl1.add(jl2);
jl1.add(jl3);
jl1.add(jl4);
jl1.add(jc1);
jl1.add(jc2);
jl1.add(jcb);
jl1.add(bu1);
jl1.add(bu2);
jl1.add(bu3);
con.add(jl1);
con.add(username);
con.add(password);
}
//**********found**********
public static void main (String[] args) {
Java_3 qq = new Java_3();
}
}
3.40
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Java_3 {
public static void main(String[] args) {
JFrame frame = new JFrame("Mouse Demo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new MousePanel());
frame.pack();
frame.setVisible(true);
}
}
//*********Found**********
class MousePanel extends JPanel {
private JLabel b;
public MousePanel() {
b = new JLabel(" 起始状态 ");
setLayout(new BorderLayout());
add(b, BorderLayout.SOUTH);
addMouseMotionListener(new MouseMotion());
setPreferredSize(new Dimension(300, 200));
}
//*********Found**********
private class MouseMotion extends MouseMotionAdapter {
public void mouseMoved(MouseEvent e) {
//*********Found**********
b.setText(" 鼠标当前位置: "+ e.getX()+ " , " + e.getY());
}
}
}
3.41
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Java_3 extends JFrame implements ActionListener{
private double x = 0;
private double y = 0;
JTextField xval = new JTextField(10);
JButton calcBtn = new JButton("计算");
JTextArea result = new JTextArea(10,20);
void initFrame(){
Container content = getContentPane();
content.setLayout(new BorderLayout());
JPanel calcPanel = new JPanel();
calcPanel.setLayout(new FlowLayout());
calcPanel.add(new JLabel("角度"));
calcPanel.add(xval);
//***************************Found*********************
calcPanel.add(calcBtn);
content.add(calcPanel,"North");
//***************************Found*********************
calcBtn.addActionListener(this);
content.add(result,"Center");
//***************************Found*********************
result.setEditable(false);
}
public Java_3(){
super("计算正弦函数");
setSize(500,200);
initFrame();
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void actionPerformed(ActionEvent e){
//***************************Found*********************
if (e.getSource()==calcBtn){
x = Double.parseDouble(xval.getText())/180*3.14;
y = Math.sin(x);
//***************************Found*********************
String str="sin("+ xval.getText() +"*3.14/180)= "+y+'\n';
//***************************Found*********************
result.append(str);
}
}
public static void main(String[] args){
new Java_3();
}
}
3.42
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
//**************found*****************
public class Java_3 extends Frame implements ItemListener{
Color color = Color.blue;
CheckboxGroup cg;
Checkbox cb1,cb2,cb3;
public Java_3(){
cg = new CheckboxGroup();
setSize(300,300);
cb1 = new Checkbox("blue",cg,true);
cb2 = new Checkbox("red",cg,true);
cb3 = new Checkbox("green",cg,true);
cg.setSelectedCheckbox(cb1);
add(cb1); add(cb2); add(cb3);
cb1.addItemListener(this);
cb2.addItemListener(this);
//**************found*****************
cb3.addItemListener(this);
}
public void itemStateChanged(ItemEvent e){
if(e.getSource()==cb1)
color=Color.blue;
if(e.getSource()==cb2)
color=Color.red;
if(e.getSource()==cb3)
color=Color.green;
repaint();
}
class MyEvent1 extends WindowAdapter {
public void windowClosing(WindowEvent e){
System.exit(0);
}
}
class MyEvent2 extends ComponentAdapter {
public void componentResized(ComponentEvent e){
repaint();
}
}
//**************found*****************
public void paint(Graphics g) {
int w = getWidth(),h=getHeight();
int x0 = w/2,y0 = h/2;
g.setColor(color);
g.drawLine(x0,0,x0,h);
g.drawLine(0,y0,w,y0);
double pi = 3.1415926,angle,rou;
int r,i,x,y;
for(r=10;r<200;r+=20){
for(i=0;i<1023;i++){
angle = i * pi/512;
rou = r * Math.sin(2*angle);
x = (int)Math.round(rou*Math.cos(angle));
y = (int)Math.round(rou*Math.sin(angle));
g.drawOval(x0+x,y0+y,1,1);
}
}
}
public static void main(String[] args){
Java_3 f = new Java_3();
MyEvent1 me1 = f.new MyEvent1();
MyEvent2 me2 = f.new MyEvent2();
//**************found*****************
f.setTitle("四叶玫瑰线");
f.setLayout(new FlowLayout());
f.addWindowListener(me1);
f.addComponentListener(me2);
//**************found*****************
f.setVisible(true);
}
}