java 验证码_彩色验证码

最新推荐文章于 2022-09-27 23:45:00 发布

转载最新推荐文章于 2022-09-27 23:45:00 发布 · 356 阅读

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#java #import #string #input #random #html

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------------产生验证码图片的文件-----image.servlet-------------------------------------------

package untitled1;

import java.io.*;

import java.net.*;

import javax.servlet.*;

import javax.servlet.http.*;

import java.awt.*;

import java.awt.image.*;

import java.util.*;

import javax.imageio.*;

/**

* @author http://www.tot.name

* @version

public class Image extends HttpServlet {

/** Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.

* @param request servlet request

* @param response servlet response

protected void processRequest(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

response.setContentType("image/jpeg");

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));

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();

}

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);

}

// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">

/** Handles the HTTP <code>GET</code> method.

* @param request servlet request

* @param response servlet response

protected void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

processRequest(request, response);

}

/** Handles the HTTP <code>POST</code> method.

* @param request servlet request

* @param response servlet response

protected void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

processRequest(request, response);

}

/** Returns a short description of the servlet.

public String getServletInfo() {

return "Short description";

}

// </editor-fold>

}

---------------使用验证码图片的文件---------index.jsp------------------------------------

<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>

<html>

<head>

<title>认证码验证页面</title>

</head>

<body>

String rand = (String)session.getAttribute("rand");

String input = request.getParameter("rand");

系统产生的认证码为： <%= rand %>

您输入的认证码为： <%= input %>

if (rand.equals(input)) {

输入相同，认证成功！

} else {

输入不同，认证失败！

}

</body>

</html>

-----------------验证的页面----------check.jsp------------------------------

<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>

<html>

<head>

<title>认证码验证页面</title>

</head>

<body>

String rand = (String)session.getAttribute("rand");

String input = request.getParameter("rand");

系统产生的认证码为： <%= rand %>

您输入的认证码为： <%= input %>

if (rand.equals(input)) {

输入相同，认证成功！

} else {

输入不同，认证失败！

}

</body>

</html>