Java绘制验证码

java绘制验证码源码如下：包括一个JFrame继承类，一个JPanel继承类。

Main.java

package game;

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;

public class Main extends JFrame {
	private MyPanel panel;
	private JButton button;
	private ActionListener listener;
	
	public Main(){
		initial();
		this.setSize(300,300);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.setVisible(true);
		
	}
	private void initial() {
		createComponent();
		layoutComponent();
		listener();
		
	}
	private void createComponent() {
		button = new JButton("change");
		panel = new MyPanel();
	}
	private void layoutComponent() {
		this.add(panel, BorderLayout.CENTER);
		this.add(button, BorderLayout.SOUTH);
		button.setActionCommand("change");
		
	}
	private void listener() {
		listener = new ActionListener() {
			
			public void actionPerformed(ActionEvent e) {
				String command = e.getActionCommand();
				if (command.equals("change")){
					repaint();
				}
			}
		};
		button.addActionListener(listener);
		
	}
	public static void main(String[] args) {
		
		Main test = new Main();
	}

}

MyPanel.java如下

package game;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import java.util.Random;

import javax.swing.JPanel;

public class MyPanel extends JPanel {

	private BufferedImage img;

	private static final int WIDTH = 180;
	private static final int HEIGHT = 40;

	public MyPanel() {

	}

	@Override
	public void paint(Graphics g1) {
		String[] fonts = { "仿宋_GB2312", "方正舒体", "黑体", "华文彩云", "华文彩云", "隶书",
				"宋体", "华文新魏", "微软雅黑", "幼圆,Arial", "Calibri", "Dotum",
				"Algerian", "Broadway", "Curlz MT", "Brush Script MT",
				"Elephant" };

		img = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
		Graphics g = img.getGraphics();
		//设置背景颜色为白色
		g.setColor(Color.WHITE);
		g.fillRect(0, 0, WIDTH, HEIGHT);
		//画一个黑色的边框
		g.setColor(Color.BLACK);
		g.drawRect(0, 0, WIDTH - 1, HEIGHT - 1);
		int x = 20;
		int y = 30;
		Random rn = new Random();

		ArrayList<Integer> list = new ArrayList<Integer>();
		//5个随机数
		for (int i = 0; i < 5; i++) {
			int n = rn.nextInt(10);
			list.add(n);
		}
		//用不同的字体和颜色画每一个数字
		for (int i = 0; i < list.size(); i++) {
			int fi = rn.nextInt(fonts.length);
			Font font = new Font(fonts[fi], Font.ITALIC, 27);
			g.setFont(font);
			Color color = new Color(rn.nextInt(256), rn.nextInt(256),
					rn.nextInt(256));
			g.setColor(color);
			g.drawString(String.valueOf(list.get(i)), x, y);
			x += 30;
		}
		// 干扰线
		for (int i = 0; i < 50; i++) {
			int x1 = rn.nextInt(WIDTH);
			int y1 = rn.nextInt(HEIGHT);
			int x2 = rn.nextInt(WIDTH);
			int y2 = rn.nextInt(HEIGHT);
			Color c = new Color(rn.nextInt(256), rn.nextInt(256),
					rn.nextInt(256), rn.nextInt(50) + 50);
			g.setColor(c);
			g.drawLine(x1, y1, x2, y2);
		}
		g1.drawImage(img, 50, 50, WIDTH, HEIGHT, null);
	}

}