Java生成随机验证码图片

Java生成随机验证码图片，结果类似于：

其中login.html网页源码为：

	
	




	
	

		用户名：

		密码：   

		
		看不清
		

		
	
	
	

Java代码为：

package com.net;

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

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 输出随机图片
 * Servlet implementation class Index2
 */
@WebServlet("/Index2")
public class Index2 extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Index2() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		int width = 120;
		int height = 25;
		// 创建内存图像
		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		// 得到画笔
		Graphics g = image.getGraphics();
			// 开始画
			g.setColor(Color.BLUE);
			g.drawRect(0, 0, width, height);
			// 填充背景色
			g.setColor(Color.YELLOW);
			g.fillRect(1, 1, width - 2, height - 2);
			// 画干扰线
			g.setColor(Color.GRAY);
			Random r = new Random();
			for (int i = 0; i < 9; i++) {
				g.drawLine(r.nextInt(width), r.nextInt(height), r.nextInt(width), r.nextInt(height));
			}
			// 验证码
			g.setColor(Color.RED);
			g.setFont(new Font("宋体", Font.ITALIC | Font.BOLD, 18));
			int x = 20;
			for (int i = 0; i < 4; i++) {
				g.drawString(r.nextInt(10) + "", x, 20);
				x += 20;
			}
		// 输出
		response.setHeader("Expires", "-1");
		response.setHeader("Cache-Control", "no-cache");
		response.setHeader("Pramgra", "no-cache");
		
		ImageIO.write(image, "jpg", response.getOutputStream());
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}