java验证码汇总

最近在弄验证码，从网上找了些代码，再整理下帖在下面，供大家参考：

1.生成gif图片格式的

package com.cssweb.common.util;

import java.io.*;
import java.util.*;
import com.sun.image.codec.jpeg.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.awt.*;
import java.awt.image.*;

/*
 * 功能：调用AuthServlet可以生成一个验证码图片,图片的宽度和高度可以自定义
 * 调用格式: /servlet/AuthServlet?width=60&height=20
 *      或者/servlet/AuthServlet
 * 时间：2007-9-4
 *  
 * 
 */
public class AuthServlet extends HttpServlet {

	private static final long serialVersionUID = 8433932715396048208L;
	private Font mFont=new Font("Times New Roman", Font.PLAIN,18);//设置字体

	// 处理post
	public void doPost(HttpServletRequest request,HttpServletResponse response)
		throws ServletException,IOException {
		doGet(request,response);
	}

	public void doGet(HttpServletRequest request,HttpServletResponse response)
     	throws ServletException,IOException {
		// 取得一个1000-9999的随机数
		HttpSession session=request.getSession();//request.getSession(false)当参数为false时，有可能不创建session
		response.setContentType("image/gif");
		response.setHeader("Pragma","No-cache");
		response.setHeader("Cache-Control","no-cache");
		response.setDateHeader("Expires", 0);
		int width=60;
		int height=20;
		if(request.getParameter("width")!=null && !request.getParameter("width").equals(""))
			width = Integer.parseInt(request.getParameter("width"));
		if(request.getParameter("height")!=null && !request.getParameter("height").equals(""))
			height = Integer.parseInt(request.getParameter("height"));
                 
	    ServletOutputStream out=response.getOutputStream();
	    BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB); //设置图片大小的
	    Graphics gra=image.getGraphics();
	    Random random=new Random();
	
	    gra.setColor(getRandColor(200,250)); //设置背景色
	    gra.fillRect(0,0,width,height);
	
	    gra.setColor(Color.black); //设置字体色
	    gra.setFont(mFont);

	    // 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
	    gra.setColor(getRandColor(160,200));
	    for (int i=0;i<155;i++) {
	    	int x = random.nextInt(width);
	    	int y = random.nextInt(height);
            int xl = random.nextInt(12);
            int yl = random.nextInt(12);
            gra.drawLine(x,y,x+xl,y+yl);
	    }

	    // 取随机产生的认证码(4位数字)
	    String sRand="";
	    for (int i=0;i<4;i++) {
	    	String rand=String.valueOf(random.nextInt(10));
	    	sRand+=rand;
	    	// 将认证码显示到图象中
	    	gra.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));//调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
	    	gra.drawString(rand,13*i+6,16);
	    }
        //System.out.println("showimage="+sRand);
        //session.setAttribute("getImg",sRand);
        session.setAttribute("vnum",sRand);
        //AuthCode = sRand;
        //session.putValue("AuthCode",sRand);
        JPEGImageEncoder encoder=JPEGCodec.createJPEGEncoder(out);
        encoder.encode(image);
        //out.flush();
	}

	static Color getRandColor(int fc,int bc){//给定范围获得随机颜色
		Random random = new Random();
		if(fc>255) fc=255;
      	if(bc>255) bc=255;
      	int r=fc+random.nextInt(bc-fc);
      	int g=fc+random.nextInt(bc-fc);
      	int b=fc+random.nextInt(bc-fc);
      	return new Color(r,g,b);
	}
   
	static public String getAuthCode(HttpSession session){//返回验证
		return (String)session.getAttribute("AuthCode");      
	}
}

2.生成png格式的图片

/*
 * @(#)version 1.0 Feb 25, 2009
 * @author hujun
 * CodeMakerServlet.java
 * Copyright 2008 CSS WEB Microsystems, Inc. All rights reserved.
 * CSS WEB ROOM PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package com.cssweb.common.util;

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

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class CodeMakerServlet extends HttpServlet {

	private static final long serialVersionUID = 8226534304924504314L;
	private Random random = new Random(new Date().getTime());
	/*
	private Font[] codeFont =
    {
        new Font("Algerian", Font.BOLD, 65), 
        new Font("Vivaldi", Font.BOLD, 85),
        new Font("Broadway", Font.BOLD, 60),
        new Font("Forte", Font.BOLD, 75)
    };
	private Color[] color =
	{
	       Color.BLACK, Color.RED, Color.DARK_GRAY, Color.BLUE
	};
	*/
	String codeNumbers = "";
	//int width = 250, height = 70;
	int width=80, height=25;
	public CodeMakerServlet() {
		super();
	}

	public void destroy() {
		super.destroy(); 
	}
	
	public void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException
	{
		// 清空缓冲区
		response.reset();
		// 注意这里的MIME类型
		response.setContentType("image/png");
		// 设置页面不缓存
		response.setHeader("Pragma", "No-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0);
		// 创建一个 250X70 的图像
		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		// 得到图形环境对象 g
		Graphics g = image.getGraphics();
		// 填充背景
		g.setColor(getRandColor(240,255));
		g.fillRect(0, 0, width, height);
		for (int i = 0; i<4; i++) {
			drawCode(g, i);
		}
		drawNoise(g, 100);
		// 绘制边框
		g.setColor(Color.black);
		//g.setColor(getRandColor(160,200));
		g.drawRect(0, 0, width - 1, height - 1);
		// 将验证码内容保存进session中
		HttpSession session = request.getSession();
		session.setAttribute("vnum", codeNumbers);
		
		// 重设字符串
		codeNumbers = "";
		// 利用ImageIO类的write方法对图像进行编码
		ServletOutputStream sos = response.getOutputStream();
		ImageIO.write(image, "PNG", sos);
		sos.close();
	}
	
	// 绘制验证码
	public void drawCode(Graphics graphics, int i)
	{
		int number = (int)(Math.random() * 10);
		graphics.setFont(new Font("Times New Roman",Font.PLAIN,24));
		graphics.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));
		//graphics.setFont(codeFont);
		//graphics.setColor(color);
		graphics.drawString("" + number, 15*i+4, 18);
		codeNumbers += number;
	}
	
	// 绘制干扰线
	public void drawNoise(Graphics graphics, int lineNumber)
	{
		graphics.setColor(getRandColor(160,200));
		for (int i = 0; i<lineNumber; i++) {
	        int x = random.nextInt(width);
	        int y = random.nextInt(height);
	        int xl = random.nextInt(12);
	        int yl = random.nextInt(12);
	        graphics.drawLine(x,y,x+xl,y+yl);
		}
	}
	
	// 处理 HTTP post 请求, 和doGet一样
	public void doPost(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException {
		doGet(request, response);
	}
	
	Color getRandColor(int fc,int bc){
        if(fc>255) fc=255;
        if(bc>255) bc=255;
        int r=fc+random.nextInt(bc-fc);
        int g=fc+random.nextInt(bc-fc);
        int b=fc+random.nextInt(bc-fc);
        return new Color(r,g,b);
    }
}