JavaBean+Servlet生成图片验证码

最新推荐文章于 2021-06-24 16:40:18 发布

原创最新推荐文章于 2021-06-24 16:40:18 发布 · 838 阅读

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#servlet #string #random #class #image #import

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本文介绍了一个简单的Java验证码生成器实现，包括生成随机字符、绘制验证码图片及配置Servlet等内容。

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今天用到，呵呵，搜索了下~~~~~~然后实现了，代码从网上down的~~~~~

其他配置嘛，自己看咯

完成javaBean:

package bean;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;
import javax.imageio.ImageIO;

public class MakeCertPic {
//验证码图片中可以出现的字符集,可根据需要修改
    private char mapTable[]={
       'a','b','c','d','e','f',
       'g','h','i','j','k','l',
       'm','n','o','p','q','r',
       's','t','u','v','w','x',
       'y','z','0','1','2','3',
       '4','5','6','7','8','9'};

    public String getCertPic(int width, int height, OutputStream os) {
   if(width<=0)width=60;
   if(height<=0)height=20;
   BufferedImage image = new BufferedImage(width, height,
          BufferedImage.TYPE_INT_RGB);
   // 获取图形上下文
   Graphics g = image.getGraphics();
   // 设定背景色
   g.setColor(new Color(0xDCDCDC));
   g.fillRect(0, 0, width, height);
   //画边框
   g.setColor(Color.black);
   g.drawRect(0,0,width-1,height-1);
   // 取随机产生的认证码
   String strEnsure = "";
   // 4代表4位验证码,如果要生成更多位的认证码,则加大数值
   for(int i=0; i<4; ++i) {
    strEnsure += mapTable[(int)(mapTable.length*Math.random())];
   }
   // 将认证码显示到图象中,如果要生成更多位的认证码,增加drawString语句
   g.setColor(Color.black);
   g.setFont(new Font("Atlantic Inline",Font.PLAIN,18));
   String str = strEnsure.substring(0,1);
   g.drawString(str,8,17);
   str = strEnsure.substring(1,2);
   g.drawString(str,20,15);
   str = strEnsure.substring(2,3);
   g.drawString(str,35,18);
   str = strEnsure.substring(3,4);
   g.drawString(str,45,15);
   // 随机产生10个干扰点
   Random rand = new Random();
   for (int i=0;i<10;i++) {
    int x = rand.nextInt(width);
    int y = rand.nextInt(height);
    g.drawOval(x,y,1,1);
   }
   // 释放图形上下文
   g.dispose();
   try {
    // 输出图象到页面
    ImageIO.write(image, "JPEG", os);
   } catch (IOException e) {
    return "";
   }
   return strEnsure;
}
}

配置servlet：位置:src/servlet

package servlet;
import java.io.IOException;
import javax.servlet.*;
import javax.servlet.http.*;
import bean.MakeCertPic;
public class ShowCertPic extends HttpServlet {
//不知道为什么单独service方法不能用
public void doPost(HttpServletRequest request,HttpServletResponse response) throws IOException,ServletException
{
  MakeCertPic image=new MakeCertPic();
  String str=image.getCertPic(0, 0, response.getOutputStream());
  request.getSession().setAttribute("certCode", str);
}
public void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException,ServletException
{
  doPost(request,response);
}

}