前言

一念放下，万般自在。

一、图形界面

package Demo01;

import java.awt.BorderLayout;
import java.awt.Container;

import javax.swing.JFrame;
import javax.swing.JTextField;

public class TestTextDemo01 extends JFrame{
          
   
	public TestTextDemo01() {
          
   
		
		Container container =this.getContentPane();
		
		JTextField textfiled = new JTextField("hello world");
		JTextField textfiled2 = new JTextField("大数据五班");
		
		container.add(textfiled,BorderLayout.NORTH);
		container.add(textfiled2,BorderLayout.SOUTH);
		
		
		this.setVisible(true);
		this.setSize(500,350);
		this.setDefaultCloseOperation(EXIT_ON_CLOSE);
	}
	
	
	public static void main(String[] args) {
          
   
		new TestTextDemo01();
		
	}

}

package Demo01;

import java.awt.BorderLayout;
import java.awt.Container;

import javax.swing.JFrame;
import javax.swing.JPasswordField;

public class TestTextDemo02 extends JFrame{
          
   
	public TestTextDemo02() {
          
   
		
		Container container =this.getContentPane();
		
		JPasswordField passwordField = new JPasswordField();
		passwordField.setEchoChar(*);
		
		
		
		container.add(passwordField);
		
		
		
		this.setVisible(true);
		this.setSize(500,350);
		this.setDefaultCloseOperation(EXIT_ON_CLOSE);
	}
	
	
	public static void main(String[] args) {
          
   
		new TestTextDemo02();
		
	}

}

二、密码框

三、鼠标监听

package Demo03;



import javax.swing.*;
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.Iterator;

//鼠标监听
public class TestMouseListener {
          
   
    public static void main(String[] args) {
          
   
        new MyFrame("我的画图");
    }
}
class MyFrame extends JFrame{
          
   
    ArrayList points;
    public MyFrame(String title){
          
   
        super(title);
        this.setBounds(200,200,400,400);
        this.setVisible(true);
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);
        points = new ArrayList<>();
        this.addMouseListener(new MyMouseListener());
    }

    @Override
    public void paint(Graphics g) {
          
   
        Iterator iterator = points.iterator();
        while (iterator.hasNext()){
          
   
            Point point = (Point) iterator.next();
            g.setColor(Color.cyan);
            g.fillOval(point.x,point.y,10,10);
        }
    }

    public void addPaint(Point point){
          
   
        points.add(point);
    }
    private class MyMouseListener extends MouseAdapter{
          
   
        @Override
        public void mousePressed(MouseEvent e) {
          
   
            MyFrame myFrame = (MyFrame) e.getSource();
            System.out.println("x左标："+e.getX()+"y左标"+e.getY());
            myFrame.addPaint(new Point(e.getX(),e.getY()));
            myFrame.repaint();

        }
    }
}