image.java

野蔷薇论坛源码 java 自己看看吧。 学习用

/* 
 * Created on 2007-2-14
 * Last modified on 2007-2-14
 * Powered by YeQiangWei.com
 */
package com.yeqiangwei.club.controller.servlet;

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.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.yeqiangwei.util.ParamUtils;

class Colors{
	
	public static Color getRandColor(int fc,int bc){
        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);
	}
	
}

public class Image  extends HttpServlet {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	
	public void doGet(HttpServletRequest request
			,HttpServletResponse response) throws IOException{
		response.setHeader("Pragma","No-cache");
		response.setHeader("Cache-Control","no-cache");
		response.setDateHeader("Expires", 0);
		//在内存中创建图象
		int width=90, height=20;
		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		//获取图形上下文
		Graphics g = image.getGraphics();
		//生成随机类
		Random random = new Random();
		//设定背景色
		g.setColor(Colors.getRandColor(200,250));
		g.fillRect(0, 0, width, height);
		//设定字体
		g.setFont(new Font("Arial Black",Font.ITALIC,18));
		//画边框
		//g.setColor(new Color());
		//g.drawRect(0,0,width-1,height-1);
		//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
		g.setColor(Colors.getRandColor(160,200));
		for (int i=0;i<300;i++)
		{
		 int x = random.nextInt(width);
		 int y = random.nextInt(height);
		        int xl = random.nextInt(12);
		        int yl = random.nextInt(12);
		 g.drawLine(x,y,x+xl,y+yl);
		}
		//取随机产生的认证码(4位数字)
		String sRand="";
		int r = 4 + (int)(Math.random()*(6-4+1));
		for (int i=0;i<r;i++){
		    String rand=String.valueOf(random.nextInt(10));
		    sRand+=rand;
		    // 将认证码显示到图象中
		    g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));
		    g.drawString(rand,13*i+6,16);
		}
		//将认证码存入SESSION
		ParamUtils.setSession(request,"rand",sRand);
		//图象生效
		g.dispose();
		//输出图象到页面
		ImageIO.write(image, "JPEG", response.getOutputStream());
	}
	
	public void doPost(HttpServletRequest request
			,HttpServletResponse response){
		
	}

}