第一步：建立一个code.jsp的页面，产生随机码
<%@ page language="java" contentType="text/html; charset=GBK" pageEncoding="GBK"
import="java.io.*,
java.util.*,
com.sun.image.codec.jpeg.*,
java.awt.*,
java.awt.image.*"%>
<%
String s = "";
int intCount = 0;
/**
* 验证码宽度
*/
int width=100;
/**
* 验证码高度
*/
int height=25;
/**
* 验证码字符集
*/
char[] code=new char[]{
'A','B','C','D','E','F','G','H','I','J','K','L','M','N','P','Q','R','S','T','U','V','W','X','Y','Z',
'a','b','c','d','e','f','g','h','i','j','k','l','m','n','p','q','r','s','t','u','v','w','x','y','z',
'2','3','4','5','6','7','8','9','开','绝','天','地','我','家','吮','光','爱','乐','笑','堂','小','昂'};
/**
* 创建一个随机数生成器类
*/
Random random = new Random();
// 随机产生codeCount数字的验证码。
for (int i = 0; i < 4; i++) {&nbs
