2017.11.29 JSP+Servlet 中功能验证码及验证的实现

源代码如下：

validate.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

<%

 String path = request.getContextPath();

 String basePath = request.getScheme() + "://"

   + request.getServerName() + ":" + request.getServerPort()

   + path + "/";

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<base href="<%=basePath%>">

<title>验证码</title>

<meta http-equiv="pragma" content="no-cache">

<meta http-equiv="cache-control" content="no-cache">

<meta http-equiv="expires" content="0">

<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

<meta http-equiv="description" content="This is my page">

<style type="text/css">

.error{

 background: url(./images/invalid_line.gif) repeat-x bottom;

 border: 1px solid red;

}

</style>

<script type="text/javascript" src="./js/jquery.js"></script>

<script type="text/javascript">

$(function(){

 $("#check").blur(function(){

  $.ajax({

   type:'post',

   url:'check',

   data: {input: $(this).val()},

   dataType: "text/json",

   success: function(msg){

    var ret = eval('(' + msg + ')');

    var success = ret.success;

    $("#tip").html(ret.message);  

    if(!success){

     $(this).val('');

     $("#image").attr('src',"validate?random="+Math.random());

     $("#check").addClass("error");

     $("#tip").css({'color':'red','font-family': '华文楷体'});

    }else{

     $("#check").removeClass("error");

     $("#tip").css({'color':'black','font-family': '华文楷体'});

    }

   }

  });

 });  

 $("#image").click(function(){

  $(this).attr('src',"validate?random="+Math.random());

 });

});

</script>

</head>

<body>

 <input type="text" id="check" value="">

 <div id="tip">&nbsp;</div>

 <br>

 <img alt="" src="validate" id="image">

</body>

</html>

web.xml

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

 version="2.5"

 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee   http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

 <servlet-mapping>

  <servlet-name>validate</servlet-name>

  <url-pattern>/validate</url-pattern>

 </servlet-mapping>

 <servlet>

  <servlet-name>validate</servlet-name>

  <servlet-class>test.MyValidateServlet</servlet-class>

 </servlet>

 <servlet-mapping>

  <servlet-name>check</servlet-name>

  <url-pattern>/check</url-pattern>

 </servlet-mapping>

 <servlet>

  <servlet-name>check</servlet-name>

  <servlet-class>test.CheckServlet</servlet-class>

 </servlet>

</web-app>

ValidateCode.java

package util;

import java.awt.Color;

import java.awt.Font;

import java.awt.Graphics;

import java.awt.image.BufferedImage;

import java.util.Random;

public class ValidateCode {

 public static final int TYPE_NUM_ONLY = 0;

 public static final int TYPE_LETTER_ONLY = 1;

 public static final int TYPE_ALL_MIXED = 2;

 public static final int TYPE_NUM_UPPER = 3;

 public static final int TYPE_NUM_LOWER = 4;

 public static final int TYPE_UPPER_ONLY = 5;

 public static final int TYPE_LOWER_ONLY = 6;

 public static String generateTextCode(int type, int length, String exChars) {

  if (length <= 0) {

   return "";

  }

  StringBuffer code = new StringBuffer();

  int i = 0;

  Random r = new Random();

  switch (type) {

  case 0:

   while (i < length) {

    int t = r.nextInt(10);

    if ((exChars == null) || (exChars.indexOf(t) < 0)) {

     code.append(t);

     i++;

    }

   }

   break;

  case 1:

   while (i < length) {

    int t = r.nextInt(123);

    if (((t >= 97) || ((t >= 65) && (t <= 90)))

      && ((exChars == null) || (exChars.indexOf((char) t) < 0))) {

     code.append((char) t);

     i++;

    }

   }

   break;

  case 2:

   while (i < length) {

    int t = r.nextInt(123);

    if (((t < 97) && ((t < 65) || (t > 90)) && ((t < 48) || (t > 57)))

      || ((exChars != null) && (exChars.indexOf((char) t) >= 0)))

     continue;

    code.append((char) t);

    i++;

   }

   break;

  case 3:

   while (i < length) {

    int t = r.nextInt(91);

    if (((t >= 65) || ((t >= 48) && (t <= 57)))

      && ((exChars == null) || (exChars.indexOf((char) t) < 0))) {

     code.append((char) t);

     i++;

    }

   }

   break;

  case 4:

   while (i < length) {

    int t = r.nextInt(123);

    if (((t >= 97) || ((t >= 48) && (t <= 57)))

      && ((exChars == null) || (exChars.indexOf((char) t) < 0))) {

     code.append((char) t);

     i++;

    }

   }

   break;

  case 5:

   while (i < length) {

    int t = r.nextInt(91);

    if ((t >= 65)

      && ((exChars == null) || (exChars.indexOf((char) t) < 0))) {

     code.append((char) t);

     i++;

    }

   }

   break;

  case 6:

   while (i < length) {

    int t = r.nextInt(123);

    if ((t >= 97)

      && ((exChars == null) || (exChars.indexOf((char) t) < 0))) {

     code.append((char) t);

     i++;

    }

   }

  }

  return code.toString();

 }

 public static BufferedImage generateImageCode(String textCode, int width,

   int height, int interLine, boolean randomLocation, Color backColor,

   Color foreColor, Color lineColor) {

  BufferedImage bim = new BufferedImage(width, height, 1);

  Graphics g = bim.getGraphics();

  g.setColor(backColor == null ? getRandomColor() : backColor);

  g.fillRect(0, 0, width, height);

  Random r = new Random();

  if (interLine > 0) {

   int x = 0;

   int y = 0;

   int x1 = width;

   int y1 = 0;

   for (int i = 0; i < interLine; i++) {

    g.setColor(lineColor == null ? getRandomColor() : lineColor);

    y = r.nextInt(height);

    y1 = r.nextInt(height);

    g.drawLine(x, y, x1, y1);

   }

  }

  int fsize = (int) (height * 0.8D);

  int fx = height - fsize;

  int fy = fsize;

  g.setFont(new Font("Default", 0, fsize));

  for (int i = 0; i < textCode.length(); i++) {

   fy = randomLocation ? (int) ((Math.random() * 0.3D + 0.6D) * height)

     : fy;

   g.setColor(foreColor == null ? getRandomColor() : foreColor);

   g.drawString(String.valueOf(textCode.charAt(i)), fx, fy);

   fx = (int) (fx + fsize * 0.9D);

  }

  g.dispose();

  return bim;

 }

 public static BufferedImage generateImageCode(int type, int length,

   String exChars, int width, int height, int interLine,

   boolean randomLocation, Color backColor, Color foreColor,

   Color lineColor) {

  String textCode = generateTextCode(type, length, exChars);

  BufferedImage bim = generateImageCode(textCode, width, height,

    interLine, randomLocation, backColor, foreColor, lineColor);

  return bim;

 }

 private static Color getRandomColor() {

  Random r = new Random();

  Color c = new Color(r.nextInt(255), r.nextInt(255), r.nextInt(255));

  return c;

 }

}

MyValidateServlet.java

package test;

import java.awt.Color;

import java.awt.image.BufferedImage;

import java.io.IOException;

import java.io.OutputStream;

import javax.imageio.ImageIO;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

import util.ValidateCode;

public class MyValidateServlet extends HttpServlet {

 private static final long serialVersionUID = 1L;

 @Override

 protected void service(HttpServletRequest req, HttpServletResponse resp)

   throws ServletException, IOException {

  resp.setHeader("Pragma", "No-cache");// 设置响应头信息，告诉浏览器不要缓存此内容

  resp.setHeader("Cache-Control", "no-cache");

  resp.setDateHeader("Expire", 0);

  try {

   String textCode = ValidateCode.generateTextCode(

     ValidateCode.TYPE_ALL_MIXED, 6, null);

   BufferedImage image = ValidateCode.generateImageCode(textCode, 500,

     100, 5, true, Color.GRAY, null, null);

   HttpSession session = req.getSession(true);

   session.setAttribute("captcha", textCode);

   resp.setContentType("image/jpeg");

   OutputStream outputStream = resp.getOutputStream();

   ImageIO.write(image, "jpeg", outputStream);

  } catch (Exception e) {

   e.printStackTrace();

  }

 }

}

CheckServlet.java

[java] view plain copy

package test;

import java.io.IOException;

import java.io.PrintWriter;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

public class CheckServlet extends HttpServlet {

 private static final long serialVersionUID = 1L;

 @Override

 protected void service(HttpServletRequest req, HttpServletResponse resp)

   throws ServletException, IOException {

  resp.setCharacterEncoding("UTF-8");

  resp.setContentType("text/html;chartset=UTF-8");

  req.setCharacterEncoding("UTF-8");

  String input = (String) req.getParameter("input");  

  HttpSession sess = req.getSession();

  String captcha = (String) sess.getAttribute("captcha");

  PrintWriter out = resp.getWriter();

  if(input.toUpperCase().equals(captcha.toUpperCase())){

   out.print("{'success': true,'message': '验证码正确！'}");

  }else{

   out.print("{'success': false,'message': '验证码错误！'}");

  }  

  out.flush();

  out.close();

 }

}

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2017.11.29 JSP+Servlet 中功能验证码及验证的实现

源代码如下：

validate.jsp

web.xml

ValidateCode.java

MyValidateServlet.java

2017.11.29 JSP+Servlet 中功能验证码及验证的实现的更多相关文章

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