表1. CheckerDrag.java
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// CheckerDrag.javaimport java.awt.*;import java.awt.event.*;public class CheckerDrag extends java.applet.Applet{ // Dimension of checkerboard square. // 棋盘上每个小方格的尺寸 final static int SQUAREDIM = 40; // Dimension of checkerboard -- includes black outline. // 棋盘的尺寸 – 包括黑色的轮廓线 final static int BOARDDIM = 8 * SQUAREDIM + 2; // Dimension of checker -- 3/4 the dimension of a square. // 棋子的尺寸 – 方格尺寸的3/4 final static int CHECKERDIM = 3 * SQUAREDIM / 4; // Square colors are dark green or white. // 方格的颜色为深绿色或者白色 final static Color darkGreen = new Color (0, 128, 0); // Dragging flag -- set to true when user presses mouse button over checker // and cleared to false when user releases mouse button. // 拖动标记 --当用户在棋子上按下鼠标按键时设为true， // 释放鼠标按键时设为false boolean inDrag = false; // Left coordinate of checkerboard's upper-left corner. // 棋盘左上角的左方向坐标 int boardx; // Top coordinate of checkerboard's upper-left corner. //棋盘左上角的上方向坐标 int boardy; // Left coordinate of checker rectangle origin (upper-left corner). // 棋子矩形原点(左上角)的左方向坐标 int ox; // Top coordinate of checker rectangle origin (upper-left corner). // 棋子矩形原点(左上角)的上方向坐标 int oy; // Left displacement between mouse coordinates at time of press and checker // rectangle origin. // 在按键时的鼠标坐标与棋子矩形原点之间的左方向位移 int relx; // Top displacement between mouse coordinates at time of press and checker // rectangle origin. // 在按键时的鼠标坐标与棋子矩形原点之间的上方向位移 int rely; // Width of applet drawing area. // applet绘图区域的宽度 int width; // Height of applet drawing area. // applet绘图区域的高度 int height; // Image buffer. // 图像缓冲 Image imBuffer; // Graphics context associated with image buffer. // 图像缓冲相关联的图形背景 Graphics imG; public void init () { // Obtain the size of the applet's drawing area. // 获取applet绘图区域的尺寸 width = getSize ().width; height = getSize ().height; // Create image buffer. // 创建图像缓冲 imBuffer = createImage (width, height); // Retrieve graphics context associated with image buffer. // 取出图像缓冲相关联的图形背景 imG = imBuffer.getGraphics (); // Initialize checkerboard's origin, so that board is centered. // 初始化棋盘的原点，使棋盘在屏幕上居中 boardx = (width - BOARDDIM) / 2 + 1; boardy = (height - BOARDDIM) / 2 + 1; // Initialize checker's rectangle's starting origin so that checker is // centered in the square located in the top row and second column from // the left. // 初始化棋子矩形的起始原点，使得棋子在第一行左数第二列的方格里居中 ox = boardx + SQUAREDIM + (SQUAREDIM - CHECKERDIM) / 2 + 1; oy = boardy + (SQUAREDIM - CHECKERDIM) / 2 + 1; // Attach a mouse listener to the applet. That listener listens for // mouse-button press and mouse-button release events. // 向applet添加一个用来监听鼠标按键的按下和释放事件的鼠标监听器 addMouseListener (new MouseAdapter () { public void mousePressed (MouseEvent e) { // Obtain mouse coordinates at time of press. // 获取按键时的鼠标坐标 int x = e.getX (); int y = e.getY (); // If mouse is over draggable checker at time // of press (i.e., contains (x, y) returns // true), save distance between current mouse // coordinates and draggable checker origin // (which will always be positive) and set drag // flag to true (to indicate drag in progress). // 在按键时如果鼠标位于可拖动的棋子上方 // （也就是contains (x, y)返回true），则保存当前 // 鼠标坐标与棋子的原点之间的距离（始终为正值）并且 // 将拖动标志设为true（用来表明正处在拖动过程中） if (contains (x, y)) { relx = x - ox; rely = y - oy; inDrag = true; } } boolean contains (int x, int y) { // Calculate center of draggable checker. // 计算棋子的中心位置 int cox = ox + CHECKERDIM / 2; int coy = oy + CHECKERDIM / 2; // Return true if (x, y) locates with bounds // of draggable checker. CHECKERDIM / 2 is the // radius. // 如果(x, y)仍处于棋子范围内则返回true // CHECKERDIM / 2为半径 return (cox - x) * (cox - x) + (coy - y) * (coy - y) CHECKERDIM / 2 * CHECKERDIM / 2; } public void mouseReleased (MouseEvent e) { // When mouse is released, clear inDrag (to // indicate no drag in progress) if inDrag is // already set. // 当鼠标按键被释放时，如果inDrag已经为true， // 则将其置为false（用来表明不在拖动过程中） if (inDrag) inDrag = false; } }); // Attach a mouse motion listener to the applet. That listener listens // for mouse drag events. //向applet添加一个用来监听鼠标拖动事件的鼠标运动监听器 addMouseMotionListener (new MouseMotionAdapter () { public void mouseDragged (MouseEvent e) { if (inDrag) { // Calculate draggable checker's new // origin (the upper-left corner of // the checker rectangle). // 计算棋子新的原点（棋子矩形的左上角） int tmpox = e.getX () - relx; int tmpoy = e.getY () - rely; // If the checker is not being moved // (at least partly) off board, // assign the previously calculated // origin (tmpox, tmpoy) as the // permanent origin (ox, oy), and // redraw the display area (with the // draggable checker at the new // coordinates). // 如果棋子（至少是棋子的一部分）没有被 // 移出棋盘，则将之前计算的原点 // (tmpox, tmpoy)赋值给永久性的原点(ox, oy)， // 并且刷新显示区域（此时的棋子已经位于新坐标上） if (tmpox boardx tmpoy boardy tmpox + CHECKERDIM boardx + BOARDDIM tmpoy + CHECKERDIM boardy + BOARDDIM) { ox = tmpox; oy = tmpoy; repaint (); } } } }); } public void paint (Graphics g) { // Paint the checkerboard over which the checker will be dragged. // 在棋子将要被拖动的位置上绘制棋盘 paintCheckerBoard (imG, boardx, boardy); // Paint the checker that will be dragged. // 绘制即将被拖动的棋子 paintChecker (imG, ox, oy); // Draw contents of image buffer. // 绘制图像缓冲的内容 g.drawImage (imBuffer, 0, 0, this); } void paintChecker (Graphics g, int x, int y) { // Set checker shadow color. // 设置棋子阴影的颜色 g.setColor (Color.black); // Paint checker shadow. // 绘制棋子的阴影 g.fillOval (x, y, CHECKERDIM, CHECKERDIM); // Set checker color. // 设置棋子颜色 g.setColor (Color.red); // Paint checker. // 绘制棋子 g.fillOval (x, y, CHECKERDIM - CHECKERDIM / 13, CHECKERDIM - CHECKERDIM / 13); } void paintCheckerBoard (Graphics g, int x, int y) { // Paint checkerboard outline. // 绘制棋盘轮廓线 g.setColor (Color.black); g.drawRect (x, y, 8 * SQUAREDIM + 1, 8 * SQUAREDIM + 1); // Paint checkerboard. // 绘制棋盘 for (int row = 0; row 8; row++) { g.setColor (((row 1) != 0) ? darkGreen : Color.white); for (int col = 0; col 8; col++) { g.fillRect (x + 1 + col * SQUAREDIM, y + 1 + row * SQUAREDIM, SQUAREDIM, SQUAREDIM); g.setColor ((g.getColor () == darkGreen) ? Color.white : darkGreen); } } } // The AWT invokes the update() method in response to the repaint() method // calls that are made as a checker is dragged. The default implementation // of this method, which is inherited from the Container class, clears the // applet's drawing area to the background color prior to calling paint(). // This clearing followed by drawing causes flicker. CheckerDrag overrides // update() to prevent the background from being cleared, which eliminates // the flicker. // AWT调用了update()方法来响应拖动棋子时所调用的repaint()方法。该方法从 // Container类继承的默认实现会在调用paint()之前，将applet的绘图区域清除 // 为背景色，这种绘制之后的清除就导致了闪烁。CheckerDrag重写了update()来 // 防止背景被清除，从而消除了闪烁。 public void update (Graphics g) { paint (g); }}
import java.awt.BorderLayout;
import java.awt.FileDialog;
import java.awt.Font;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.StringSelection;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.border.TitledBorder;
/*因为根据个人的电脑路径可能有所偏差，没有源路径的情况下，设置默认保存路径为D盘根目录下
* 若要选择保存其他地方，可以选择 另存为*/
public class TestDemo extends JFrame {
private static final long serialVersionUID = -5355432125621015300L;
private String url = null;//文件路径
private String str=null;//复制或剪切 的字符串
private StringSelection stringSelection=null;
private Clipboard clipboard=new Clipboard(str);
private Transferable transferable=null;
private DataFlavor flavor=null;
public TestDemo() {
init();
}
private void init() {
setTitle("我的记事本");
setSize(500, 600);
setContentPane(createContentPane());//添加主面板
}
/*创建主面板*/
private JPanel createContentPane() {
JPanel pane = new JPanel(new BorderLayout());
pane.add(BorderLayout.NORTH, createChocePane());//添加菜单栏
pane.add(createAreaPane());//添加文本编辑区域
return pane;
}
/*创建菜单栏，以及实现功能*/
private JPanel createChocePane() {
JPanel pane = new JPanel();
JMenuBar menuBar1 = new JMenuBar();
JMenu menu = new JMenu("文件");
menuBar1.add(menu);
JMenuItem menuIt1 = new JMenuItem("新建");
JMenuItem menuIt2 = new JMenuItem("打开");
JMenuItem menuIt3 = new JMenuItem("保存");
JMenuItem menuIt4 = new JMenuItem("另存为");
menu.add(menuIt1);
menu.add(menuIt2);
menu.add(menuIt3);
menu.add(menuIt4);
JMenuBar menuBar2 = new JMenuBar();
JMenu menu2 = new JMenu("编辑");
menuBar2.add(menu2);
JMenuItem menuIt5 = new JMenuItem("复制");
JMenuItem menuIt6 = new JMenuItem("剪切");
JMenuItem menuIt7 = new JMenuItem("粘帖");
menu2.add(menuIt5);
menu2.add(menuIt6);
menu2.add(menuIt7);
JMenuBar menuBar3 = new JMenuBar();
JMenu menu3 = new JMenu("帮助");
menuBar3.add(menu3);
JMenuItem menuIt8 = new JMenuItem("关于记事本");
menu3.add(menuIt8);
pane.add(menuBar1);
pane.add(menuBar2);
pane.add(menuBar3);
menuIt1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
testArea.setText(null);
}
});
menuIt2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
final FileDialog fd = new FileDialog(new JFrame(), "查找文件",
FileDialog.LOAD);
fd.setVisible(true);
if (fd.getDirectory() != null fd.getFile() != null) {
testArea.setText(null);
url = fd.getDirectory() + fd.getFile();
try {
BufferedReader in = new BufferedReader(new FileReader(
url));
for (int i = 0;; i++) {
testArea.append(in.readLine());
if (in.read() == -1) {
break;
} else
continue;
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
});
menuIt3.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (url==null) {
url="D:\\新建 文本文档.txt";
}
File f = new File(url);
BufferedWriter out = null;
try {
out = new BufferedWriter(new FileWriter(url));
f.createNewFile();
out.append(testArea.getText());
out.flush();
} catch (IOException e1) {
e1.printStackTrace();
} finally {
try {
out.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
});
menuIt4.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
FileDialog fd = new FileDialog(new JFrame(), "保存文本",
FileDialog.SAVE);
fd.setVisible(true);
if (url!=null) {
File f = new File(url);
BufferedWriter out = null;
try {
f.createNewFile();
out = new BufferedWriter(new FileWriter(url));
out.append(testArea.getText());
out.flush();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
});
menuIt5.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
str=testArea.getSelectedText();
stringSelection=new StringSelection(str);
clipboard.setContents(stringSelection, null);
}
});
menuIt6.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
str=testArea.getSelectedText();
stringSelection=new StringSelection(str);
clipboard.setContents(stringSelection, null);
int start=testArea.getSelectionStart();
int end=testArea.getSelectionEnd();
testArea.replaceRange( null,start,end);
}
});
menuIt7.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
transferable=clipboard.getContents(this);
flavor=DataFlavor.stringFlavor;
if (transferable.isDataFlavorSupported(flavor)) {
int start=testArea.getSelectionStart();
int end=testArea.getSelectionEnd();
testArea.replaceRange( null,start,end);
int pos=testArea.getCaretPosition();
try {
str=(String)transferable.getTransferData(flavor);
testArea.insert(str, pos);
} catch (UnsupportedFlavorException e1) {
e1.printStackTrace();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
});
menuIt8.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JOptionPane.showMessageDialog(null,"功能简单，绝对原创 ");
}
});
return pane;
}
JTextArea testArea;
private JScrollPane createAreaPane() {
JScrollPane pane = new JScrollPane();
pane.setBorder(new TitledBorder("编辑区域"));
testArea = new JTextArea();
testArea.setFont(new Font("宋体", Font.BOLD, 13));
testArea.setLineWrap(true);
pane.getViewport().add(testArea);
return pane;
}
public static void main(String[] args) {
TestDemo td = new TestDemo();
td.setVisible(true);
}
}
1、第一个Swing程序——JFrame窗体
需要注意的是 JFrame窗体在初始设置的时候存在几个问题：
1 窗体默认不可见，需要设置成为可见
2 窗体默认没有大小，需要设置其大小
3 窗体默认不能关闭，需要设置关闭方式
2、JFrame中添加面板、布局方式与控件
你说的java源代码是指编译成的class文件前的java文件。
当我们运行.java文件时，它会被系统编译成.class文件，例如Test.java编译之后就是Test.class，
源文件就是指Test.java文件，
一般部署项目时，有.class文件就可以发布运行了，但是如果想修改这个系统，.class是不能修改的，要有.java文件才能修改
也可以上网去下反编译软件，就是能把.class文件大部分还原成.java文件的工具，但不是100%还原，而且如果不是正版的，小心有毒啊，什么的。
import java.util.Scanner;
public class test {
public static void main(String[] args) {
int j = 0;// 从0米开始跑
Scanner in = new Scanner(System.in);
while(true) {
System.out.println("你跑了多少米？");
j = in.nextInt();
System.out.println("口渴吗？请输入(yes or no)");
String thirst = in.next();
if (j 400) {
if (!thirst.equals("yes")) {
System.out.println("好吧，那你继续跑吧！");
continue; // 不喝水，继续跑
} else {
System.out.println("过来喝水吧");
}
break;
}
else{
continue;
}
}
}
}
谢谢采纳
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
public class GradeStatistic {
public static void main(String[] args) {
GradeStatistic gs = new GradeStatistic();
ListMark list = new ArrayListMark();
float sum = 0;
while(true){
Scanner sc = new Scanner(System.in);
System.out.print("Please input student name: ");
String name = sc.nextLine();
if(name.equals("end")){
break;
}
System.out.print("Please input student score: ");
float score = sc.nextFloat();
sum += score;
list.add(gs.new Mark(name, score));
}
float max = list.get(0).getScore();
float min = list.get(0).getScore();
for(Mark mark: list){
if(max mark.getScore()){
max = mark.getScore();
}
if(min mark.getScore()){
min = mark.getScore();
}
}
float average = sum / list.size();
System.out.println("Average is: " + average);
System.out.println("Max is: " + max);
System.out.println("Min is: " + min);
}
private class Mark{
private String name;
private float score;
public Mark(String name, float score){
this.name = name;
this.score = score;
}
public String getName() {
return name;
}
public float getScore() {
return score;
}
}
}
----------------------
Please input student name: Zhang san
Please input student score: 100
Please input student name: Li Si
Please input student score: 91
Please input student name: Ec
Please input student score: 35
Please input student name: ma qi
Please input student score: 67
Please input student name: end
Average is: 73.25
Max is: 100.0
Min is: 35.0
