错误: 严重: Servlet.service() for servlet jsp threw exception java.lang.IllegalStateException: getOutputStream() has already been called 输出验证码的类: package com.jxc.util;import java.awt.Color;impo
参考代码: <!DOCTYPE html><html><head><script src="http://libs.baidu.com/jquery/1.10.2/jquery.min.js"></script><script type="text/javascript"> var countdown=60; function settime(obj) { if (countdo
前端html页面代码 1.html <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><title>1.html</title><meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="