JAVA截屏

package Rong;
import java.awt.AWTException;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionAdapter;
import java.awt.image.BufferedImage;
import java.awt.image.RescaleOp;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.filechooser.FileSystemView;


public class SnapshotTest {
 public static void main(String[] args) {
  //全屏运行
  RectD rd = new RectD();
  GraphicsDevice gd =GraphicsEnvironment.getLocalGraphicsEnvironment()
   .getDefaultScreenDevice();
  gd.setFullScreenWindow(rd);
 }
}

class RectD extends JFrame {
 private static final long serialVersionUID =1L;
 int orgx, orgy, endx, endy;//鼠标按下和释放时x、y轴坐标
 Dimension d =Toolkit.getDefaultToolkit().getScreenSize();//获得屏幕大小
 BufferedImage image;//存储整个屏幕
 BufferedImage tempImage;//缓存
 BufferedImage saveImage;//保存(截取的区域)
 Graphics g;

 @Override
 public void paint(Graphics g) {
  RescaleOp ro = new RescaleOp(0.8f, 0,null);//构造一个具有所希望的缩放因子和偏移量的新 RescaleOp
  tempImage = ro.filter(image, null);//对源BufferedImage对象image进行重缩放
  g.drawImage(tempImage, 0, 0, this);
 }

 public RectD() {
  snapshot();
  setVisible(true);//设置窗口可见
  setSize(d);//最大化窗口
 setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//默认关闭方式
  this.addMouseListener(new MouseAdapter() {
   public voidmousePressed(MouseEvent e) {
    orgx =e.getX();
    orgy =e.getY();
   }
  });
  this.addMouseMotionListener(newMouseMotionAdapter() {
   public voidmouseDragged(MouseEvent e) {
    endx =e.getX();
    endy =e.getY();
    g =getGraphics();
   g.drawImage(tempImage, 0, 0, RectD.this);
    int x =Math.min(orgx, endx);
    int y =Math.min(orgy, endy);
    int width =Math.abs(endx - orgx)+1;
    int height =Math.abs(endy - orgy)+1;
   //加上1，防止width或height为0
   g.setColor(Color.BLUE);
   g.drawRect(x-1, y-1, width+1, height+1);
   //减1，加1都是为了防止图片将矩形框覆盖掉
    saveImage =image.getSubimage(x, y, width, height);
   g.drawImage(saveImage, x, y, RectD.this);
   }
  });
  this.addKeyListener(new KeyAdapter() {
   public voidkeyReleased(KeyEvent e) {
   //按Esc键
   if(e.getKeyCode() == 27) {
    if(saveImage!=null){
     saveToFile();//保存图片     
    }
    System.exit(0);//退出
    }
   }
  });
  this.addMouseListener(new MouseListener(){
   @Override
   public voidmouseClicked(MouseEvent e) {//单击(双击)组件时调用
    // TODOAuto-generated method stub
   //双击鼠标左键
   if(e.getClickCount()==2){
    if(saveImage!=null){//如果截图了则保存图片到桌面
     saveToFile();     
    }
    System.exit(0);//退出
    }
   }
   @Override
   public voidmouseEntered(MouseEvent e) {//进入组件时调用
    // TODOAuto-generated method stub
    
   }
   @Override
   public voidmouseExited(MouseEvent e) {//离开组件时调用
    // TODOAuto-generated method stub
    
   }
   @Override
   public voidmousePressed(MouseEvent e) {//在组件上按下鼠标按键时调用
    // TODOAuto-generated method stub
   //点击鼠标右键则退出程序
   if(e.getModifiers()==MouseEvent.BUTTON3_MASK){
    System.exit(0);
    }
   }
   @Override
   public voidmouseReleased(MouseEvent e) {//在组件上释放鼠标按钮时调用
    // TODOAuto-generated method stub
    
   }  
  });
 }
 //保存图片到桌面，图片名称格式为yyyymmddHHmmss.jpg
 public void saveToFile() {
  SimpleDateFormat sdf = newSimpleDateFormat("yyyymmddHHmmss");
  String name = sdf.format(newDate());//格式转化获得图片名
  File path =FileSystemView.getFileSystemView().getHomeDirectory();//获得桌面路径
  String format = "jpg";
  File f = new File(path + File.separator + name +"." + format);
  try {
   ImageIO.write(saveImage,format, f);//生成图片
  } catch (IOException e) {//抛出异常
   e.printStackTrace();
  }
 }

 public void snapshot() {
  try {
   Robot robot = newRobot();//在基本屏幕坐标系中构造一个 Robot对象
   Dimension d =Toolkit.getDefaultToolkit().getScreenSize();
   image =robot.createScreenCapture(new Rectangle(0, 0,d.width,d.height));//获得整个屏幕
  } catch (AWTException e) {
   e.printStackTrace();
  }
 }
}