How to write a screenshot gadget in Java?

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
public class PrintScreen extends JFrame{
    PrintScreen(){
        this.setTitle("Java屏幕截图小工具");
        this.setSize(400,300);
        this.setVisible(true);
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);
        JButton jButton=new JButton("点击截图");
        jButton.setSize(120,60);
        setLayout(new FlowLayout());
        getContentPane().add(jButton);
        //为按钮添加监听事件
        jButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    PrintScreen();
                } catch (AWTException | IOException ex) {
                    throw new RuntimeException(ex);
                }
            }
        });
    }
    
	//实现截图功能
    public static void PrintScreen() throws AWTException, IOException {
        Dimension screenSize=Toolkit.getDefaultToolkit().getScreenSize();
        int width=(int)screenSize.getWidth();
        int height=(int)screenSize.getHeight();
        Robot robot=new Robot();
        BufferedImage bi=robot.createScreenCapture(new Rectangle(width,height));
        ImageIO.write(bi,"png",new File("C:\\Users\\Administrator\\Desktop","上一张截图.png"));
    }
    public static void main(String[] args){
        PrintScreen printScreen=new PrintScreen();
    }
}