java实现捕捉屏幕

要使用的是java.util.Robot类来捕获屏幕,可以实现对屏幕一个矩形区域的捕获,通过这个类,我们也可以实现一个远程桌面控制的程序package com.qiu.util;import java.io.*;import java.net.*;import javax.swing.*;import java.awt.*;import java.awt.event.*;import java.awt.image.*;import javax.imageio.*;import java.io.*;/**@Author Qiu_BaiChao*一个简单的屏幕抓图***/public class ScreenCapture {//test mainpublic static void main(String[] args) throws Exception{  String userdir = System.getProperty("user.dir");  File tempFile = new File("d:","temp.png");   ScreenCapture capture = ScreenCapture.getInstance();  capture.captureImage();    JFrame frame = new JFrame();  JPanel panel = new JPanel();  panel.setLayout(new BorderLayout());  JLabel imagebox = new JLabel();  panel.add(BorderLayout.CENTER,imagebox);    imagebox.setIcon(capture.getPickedIcon());  capture.saveToFile(tempFile);  capture.captureImage();  imagebox.setIcon(capture.getPickedIcon());  frame.setContentPane(panel);  frame.setSize(400,300);  frame.show();  System.out.println("Over");}private ScreenCapture() {    try{   robot = new Robot();  }  catch(AWTException e) {   System.err.println("Internal Error: " + e);   e.printStackTrace();  }    JPanel cp = (JPanel)dialog.getContentPane();  cp.setLayout(new BorderLayout());    labFullScreenImage.addMouseListener(new MouseAdapter() {    public void mouseReleased(MouseEvent evn) {      isFirstPoint = true;      pickedImage = fullScreenImage.getSubimage(recX,recY,recW,recH);      dialog.setVisible(false);         }   });     labFullScreenImage.addMouseMotionListener(new MouseMotionAdapter() {    public void mouseDragged(MouseEvent evn) {     if(isFirstPoint) {      x1 = evn.getX();      y1 = evn.getY();      isFirstPoint = false;       }     else {      x2 = evn.getX();      y2 = evn.getY();      int maxX = Math.max(x1,x2);      int maxY = Math.max(y1,y2);      int minX = Math.min(x1,x2);      int minY = Math.min(y1,y2);      recX = minX;      recY = minY;      recW = maxX-minX;      recH = maxY-minY;      labFullScreenImage.drawRectangle(recX,recY,recW,recH);         }    }        public void mouseMoved(MouseEvent e) {     labFullScreenImage.drawCross(e.getX(),e.getY());    }   });     cp.add(BorderLayout.CENTER,labFullScreenImage);  dialog.setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));  dialog.setAlwaysOnTop(true);  dialog.setMaximumSize(   Toolkit.getDefaultToolkit().getScreenSize());  dialog.setUndecorated(true);  dialog.setSize(dialog.getMaximumSize());  dialog.setModal(true);}//Singleton Patternpublic static ScreenCapture getInstance() {  return defaultCapturer;}/**捕捉全屏慕*/public Icon captureFullScreen() {  fullScreenImage = robot.createScreenCapture(new Rectangle(   Toolkit.getDefaultToolkit().getScreenSize()));  ImageIcon icon = new ImageIcon(fullScreenImage);  return icon;}/**捕捉屏幕的一个矫形区域  */public void captureImage() {  fullScreenImage = robot.createScreenCapture(new Rectangle(   Toolkit.getDefaultToolkit().getScreenSize()));  ImageIcon icon = new ImageIcon(fullScreenImage);  labFullScreenImage.setIcon(icon);    dialog.setVisible(true); }/**得到捕捉后的BufferedImage*/ public BufferedImage getPickedImage() {  return pickedImage;}/**得到捕捉后的Icon*/ public ImageIcon getPickedIcon() {  return new ImageIcon(getPickedImage());}/**储存为一个文件,为PNG格式  *@deprecated  *replaced by saveAsPNG(File file)  **/@Deprecatedpublic void saveToFile(File file) throws IOException{  ImageIO.write(getPickedImage(),defaultImageFormater,file);}/**储存为一个文件,为PNG格式*/public void saveAsPNG(File file) throws IOException {  ImageIO.write(getPickedImage(),"png",file);}/**储存为一个JPEG格式图像文件*/public void saveAsJPEG(File file) throws IOException {  ImageIO.write(getPickedImage(),"JPEG",file);}/**写入一个OutputStream*/public void write(OutputStream out) throws IOException{  ImageIO.write(getPickedImage(),defaultImageFormater,out);}//singleton design patternprivate static ScreenCapture defaultCapturer = new ScreenCapture(); private int x1,y1,x2,y2;private int recX,recY,recH,recW; //截取的图像private boolean isFirstPoint  = true;private BackgroundImage labFullScreenImage = new BackgroundImage();private Robot robot;private BufferedImage fullScreenImage;private BufferedImage pickedImage;private String defaultImageFormater = "png";private JDialog dialog = new JDialog();}/**显示图片的Label*/class BackgroundImage extends JLabel{public void paintComponent(Graphics g) {  super.paintComponent(g);  g.drawRect(x,y,w,h);  String area = Integer.toString(w)+" * "+ Integer.toString(h);  g.drawString(area,x+(int)w/2-15,y+(int)h/2);  g.drawLine(lineX,0,lineX,getHeight());  g.drawLine(0,lineY,getWidth(),lineY);}public void drawRectangle(int x,int y,int width,int height) {  this.x = x;  this.y = y;  h = height;  w = width;  repaint();}public void drawCross(int x,int y) {  lineX = x;  lineY = y;  repaint();}int lineX,lineY;int x,y,h,w;}