可自定义的验证码--Kaptcha

• 可自定义的验证码--Kaptcha - [小知识记录]

  使用方法就是: 先下载http://code.google.com/p/kaptcha/下载

  把kaptcha-2.3.jar把文件到 WEB-INF/lib目录下

   web.xml配置信息：

  <?xml version="1.0" encoding="UTF-8"?>
  <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
   xsi:schemaLocation="http://java.sun.com/xml/ns/javaeehttp://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
   id="WebApp_ID" version="2.5">
   <display-name>kaptcha</display-name>
   
   <servlet>
    <servlet-name>Kaptcha</servlet-name>
    <servlet-class>com.google.code.kaptcha.servlet.KaptchaServlet</servlet-class>
    <!-- 设置是否有边框 -->
    <init-param>
     <param-name>kaptcha.border</param-name>
     <param-value>yes</param-value>
    </init-param>
    <!-- 设置边框颜色-->
    <init-param>
     <param-name>kaptcha.border.color</param-name>
     <param-value>105,179,90</param-value>
    </init-param>
    <!-- 获取中文 -->
    <init-param>
     <param-name>kaptcha.textproducer.impl</param-name>
     <param-value>org.cric.util.ChineseText</param-value>
    </init-param>
    <!-- 设置字体颜色 -->
    <init-param>
     <param-name>kaptcha.textproducer.font.color</param-name>
     <param-value>black</param-value>
    </init-param>
    <!-- 设置验证码宽度 -->
    <init-param>
     <param-name>kaptcha.image.width</param-name>
     <param-value>130</param-value>
    </init-param>
    <!-- 设置验证码高度 -->
    <init-param>
     <param-name>kaptcha.image.height</param-name>
     <param-value>44</param-value>
    </init-param>
    <!-- 设置字体大小 -->
    <init-param>
     <param-name>kaptcha.textproducer.font.size</param-name>
     <param-value>30</param-value>
    </init-param>
    <!-- 设置字体个数 -->
    <init-param>
     <param-name>kaptcha.textproducer.char.length</param-name>
     <param-value>4</param-value>
    </init-param>
    <!-- 设置字体样式 -->
    <init-param>
     <param-name>kaptcha.textproducer.font.names</param-name>
     <param-value>宋体,楷体,微软雅黑</param-value>
    </init-param>

   </servlet>
   <servlet-mapping>
    <servlet-name>Kaptcha</servlet-name>
    <url-pattern>/kaptcha.jpg</url-pattern>
   </servlet-mapping>

   <welcome-file-list>
    <welcome-file>index.html</welcome-file>
   </welcome-file-list>
  </web-app>

  这个插件自带了个中文生成类，但是这个类做得很死，中文是手动输入进去的，我的天，太死了，然后leo就找啊找，发现API中有一个自定义接口，哈哈，太好了，正好我之前有一个生成中文的程序，直接COPY过来，写了个简单的类，测试，成功了，就是上面发的图。接口是这个

  package org.cric.util;

  import java.util.Random;
  import com.google.code.kaptcha.text.TextProducer;
  import com.google.code.kaptcha.util.Configurable;

  /**
   *  随机产生字符，包括汉字 length 表示 长度
   * @author qcy
   *
   */ 
  public class ChineseText extends Configurable implements TextProducer{ 
   
      public String getText() { 
          int length = getConfig().getTextProducerCharLength(); 
          //int length = 4; 
          String finalWord="",firstWord=""; 
          int tempInt=0; 
          String[] array={ 
                  "0","1","2","3", 
                  "4","5","6","7", 
                  "8","9","a","b", 
                  "c","d","e","f"}; 
           
          Random rand = new Random(); 
           
          for(int i=0;i<length;i++){ 
              switch(rand.nextInt(3)){ 
                  case 1: 
                          tempInt=rand.nextInt(26)+65; 
                          firstWord=String.valueOf((char)tempInt); 
                          break; 
                  case 2: 
                          int r1,r2,r3,r4; 
                          String strH,strL;// high&low 
                          r1=rand.nextInt(3)+11; // 前闭后开[11,14) 
                          if(r1==13){ 
                              r2=rand.nextInt(7); 
                          }else{ 
                              r2=rand.nextInt(16); 
                          } 
                           
                          r3=rand.nextInt(6)+10; 
                          if(r3==10){ 
                              r4=rand.nextInt(15)+1; 
                          }else if(r3==15){ 
                              r4=rand.nextInt(15); 
                          }else{ 
                              r4=rand.nextInt(16); 
                          } 
                           
                          strH=array[r1]+array[r2]; 
                          strL=array[r3]+array[r4]; 
                           
                          byte[] bytes=new byte[2]; 
                          bytes[0]=(byte)(Integer.parseInt(strH,16)); 
                          bytes[1]=(byte)(Integer.parseInt(strL,16)); 
                           
                          firstWord=new String(bytes); 
                          break; 
                  default: 
                          tempInt=rand.nextInt(10)+48; 
                          firstWord=String.valueOf((char)tempInt); 
                          break; 
              } 
              finalWord+=firstWord; 
          } 
          return finalWord; 
      } 
      public static void main(String[] args) { 
          // TODO Auto-generated method stub 
          ChineseText ct = new ChineseText(); 
          System.out.print(ct.getText()); 
   
      } 
  } 

  Java中获取真实的验证码:

     String kaptchaExpected = (String)request.getSession().getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY);

  页面代码：

  <img src="<%=path%>/kaptcha.jpg" id="randImg"  onclick="refresh(this);" alt="看不清楚，点击获得新图片" />

  刷新js:

  function refresh(o){
   //重载验证码
   var timenow = new Date().getTime();
   o.src="<%=path%>/kaptcha.jpg?d="+timenow;
   
   //超时执行;
   setTimeout(function(){
    o.src="<%=path%>/kaptcha.jpg?d="+timenow;
   }
    ,20);
   
  }

参考：http://peony07.blogbus.com/logs/75198021.html