验证码

 

 package com.chintrip.util;

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

import javax.imageio.ImageIO;

/**
 * @author haisheng
 *
 */
public class ImgUtil {

	
	public static byte[] creatImage(char[] rands,int WIDTH, int HEIGHT) throws IOException {
		
		
		// 创建内存图象并获得其图形上下文
		BufferedImage image = new BufferedImage(WIDTH, HEIGHT,
				BufferedImage.TYPE_INT_RGB);

		Graphics g = image.getGraphics();	

		// 产生图像
		drawBackground(g, WIDTH, HEIGHT);

		drawRands(g, rands);

		// 结束图像的绘制过程，完成图像
		g.dispose();

		// 将图像输出到客户端
		ByteArrayOutputStream bos = new ByteArrayOutputStream();
		
		ImageIO.write(image, "JPEG", bos);
		
		byte[] buf = bos.toByteArray();
		 bos.close();   
		return buf;
		

	}

	// 获取随机颜色
	private static Color randomColor() {
		Random rand = new Random();
		
		return new Color(Math.abs(rand.nextInt()) % 256, Math.abs(rand
				.nextInt()) % 256, Math.abs(rand.nextInt()) % 256);
	}
	
	private static void drawRands(Graphics g, char[] rands) {

		g.setFont(new Font(null, Font.ITALIC | Font.BOLD, 24));

		// 在不同的高度上输出验证码的每个字符
		g.setColor(randomColor());
		g.drawString("" + rands[0], 1, 19);
		g.setColor(randomColor());
		g.drawString("" + rands[1], 16, 25);
		g.setColor(randomColor());
		g.drawString("" + rands[2], 31, 20);
		g.setColor(randomColor());
		g.drawString("" + rands[3], 46, 23);

		System.out.println(rands);
	}

	private static void drawBackground(Graphics g, int WIDTH, int HEIGHT)
	{
		// 画背景
		g.setColor(new Color(0xDCDCDC));
		g.fillRect(0, 0, WIDTH, HEIGHT);

		// 随机产生120个干扰点
		for (int i = 0; i < 120; i++)
		{
			int x = (int) (Math.random() * WIDTH);

			int y = (int) (Math.random() * HEIGHT);

			int red = (int) (Math.random() * 255);

			int green = (int) (Math.random() * 255);

			int blue = (int) (Math.random() * 255);

			g.setColor(new Color(red, green, blue));

			g.drawOval(x, y, 1, 0);

		}

	}

}

 

 

 

   

 package com.chintrip.util;
 
 public class GenerateRandomCode
 {
	 
   public static char[] checkCode(int length)
   {
     String chars = "123456789ABCDEFGHIJKLMNPQRSTUVWXYZ";
     
     char[] rands = new char[length];
     for (int i = 0; i < length; ++i)
     {
       int rand = (int)(Math.random() * 34.0D);
       rands[i] = chars.charAt(rand);
     }
     
     return rands;
   }
 
   public static String randomCode(int length)
   {
     String chars = "0123456789ABCDEFGHIJKLMNPQRSTUVWXYZO";
     StringBuffer bf = new StringBuffer();
     for (int i = 0; i < length; ++i) {
       int rand = (int)(Math.random() * 36.0D);
       bf.append(chars.charAt(rand));
     }
     return bf.toString();
   }
   
   public static String randomNumberCode(int length)
   {
     String chars = "0123456789";
     StringBuffer bf = new StringBuffer();
     for (int i = 0; i < length; ++i) {
       int rand = (int)(Math.random() * 10);
       bf.append(chars.charAt(rand));
     }
     return bf.toString();
   }
   
   public static void main(String[] args) {
	   for(int i=0;i<20;i++){
		   System.out.println(randomNumberCode(6));
	   }
	   
}
 
 }

   
  

package com.chintrip.controller;
@Controller
@RequestMapping("/imgValidate")
public class ImgValidateAction {
	 
	 private static int WIDTH = 80;   
	 private static int HEIGHT = 25; 
	 
	@RequestMapping("")
	public void index(HttpServletRequest request, HttpServletResponse response) throws IOException{
		HttpSession session = request.getSession();   
		  
        response.setContentType("image/jpeg");   
        
        ServletOutputStream sos = response.getOutputStream();   
        
        //设置浏览器不要缓存此图片   
        response.setHeader("Pragma","No-cache");   
        response.setHeader("Cache-Control","no-cache");   
        // 产生随机的认证码
		char[] rands = GenerateRandomCode.checkCode(4);
        byte [] buf =ImgUtil.creatImage(rands,WIDTH, HEIGHT);   
        
        response.setContentLength(buf.length);           
        //下面的语句也可写成：bos.writeTo(sos);   
        sos.write(buf);           
        sos.close();   
        //将当前验证码存入到Session
        session.setAttribute(SysConstant.session_check_code,new String(rands));   
		
	}
}

 

   

$(function(){
	changeValidateCode();
});

function changeValidateCode(){
       var timenow = new Date().getTime();       
        $("#getimage").src="  <%=path%>/imgValidate?p="+timenow;
}

    

	<a href="javascript:changeValidateCode();"><img
																					id="getimage" style="border: 0px none;"
																					src="<%=path%>/common_images/loading.gif"
																					align="absmiddle" title="点击图片刷新验证码"> </a>