Java截屏

import java.awt.AWTException;
import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;

/**
 * Robot实现监控屏幕,实现效果是每隔50微秒获取当前屏幕图像，显示到JFrame内
 *
 * @author dingxiaochao
 * @date 2018/10/10 14:24
 * @param
 * @return
 */
public class RobotScreenTest {
    public static void main(String[] args){
        try {
            Robot robot = new Robot();
            JFrame jframe = new JFrame();
            //设置标题
            jframe.setTitle("监控屏幕工具");
            JLabel label = new JLabel();
            jframe.add(label);
            jframe.setSize(800,600);
            //设置可见
            jframe.setVisible(true);
            //设置置顶
            jframe.setAlwaysOnTop(true);
            //控制台退出模式
            jframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            //获取屏幕大小
            Toolkit toolkit = Toolkit.getDefaultToolkit();
            Dimension dm = toolkit.getScreenSize();
            while(true){
                //一个矩形面板
                Rectangle rec = new Rectangle(0, 0, (int)dm.getWidth(), (int)dm.getHeight());
                //按照矩形截取图片到缓冲流
                BufferedImage img = robot.createScreenCapture(rec);
               
                //用于持久化存储
                try {
                    File outputfile = new File("saved.jpg");
                    ImageIO.write(img, "jpg", outputfile);
                } catch (Exception e) {
                    e.printStackTrace();
                }
                //缩放图片
                BufferedImage newImg = RobotScreenTest.resize(img, jframe.getWidth(), jframe.getHeight());
                label.setIcon(new ImageIcon(newImg));
                try {
                    Thread.sleep(50);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        } catch (AWTException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    
    public static BufferedImage resize(BufferedImage img, int newW, int newH){
        int w = img.getWidth();
        int h = img.getHeight();
        //创建一个缩放后的图片流
        BufferedImage newImg = new BufferedImage(newW,newH,img.getType());
        Graphics2D g = newImg.createGraphics();
        //设置模式
        g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,RenderingHints.VALUE_INTERPOLATION_BILINEAR);
        //按比例缩放
        g.drawImage(img, 0, 0, newW, newH, 0, 0, w, h, null);
        g.dispose();
        return newImg;
    }
}