vcodeaction.java

人力资源管理系统

/*
 * Generated by MyEclipse Struts
 * Template path: templates/java/JavaClass.vtl
 */
package com.accphr.web.action;

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

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

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;


public class VcodeAction extends Action {

	public ActionForward execute(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response) throws Exception {
		 response.setContentType("image/jpeg");
		    //清除页面上的缓存(每次点击浏览器的后退按钮都会重新生成验证码)
		    response.setHeader("Pragma","No-cache");
		    response.setHeader("Cache-Control","no-cache");
		   response.setDateHeader("Expires", 0); 
		   HttpSession session=request.getSession();
		   // 在内存中创建图象
		    int width=60, 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(getRandColor(200,250));
		//填充整个画布
		g.fillRect(0, 0, width, height);
		//设定字体
		g.setFont(new Font("Times New Roman",Font.PLAIN,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(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);
		g.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
		            g.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
		g.drawString(rand, 13*i+6, 16);
		}
		// 将认证码存入session
		session.setAttribute("rand",sRand);
		// 图象生效
		g.dispose();
		ServletOutputStream responseOutputStream =response.getOutputStream();
		// 输出图象到页面
		ImageIO.write(image, "JPEG", responseOutputStream);
		//以下关闭输入流！
		responseOutputStream.flush();
		responseOutputStream.close();

		return null;
	}
	
	//获得随机颜色对象
	private 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);
	}
}