项目准备之小工具VerifyCodeServlet的使用

2025-02-24 技术教程

生成验证码

<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>表单提交</title><script type="text/javascript">function _hyz() { /* 1. 获取img元素 2. 改变src的指向 */ var img = document.getElementById("img"); //需要加一个参数才能干掉浏览器的缓存 img.src = "/tools/VerifyCodeServlet?a=" + new Date().getTime();}</script></head><body><form action="/tools/loginServlet" method="post">  <input type="hidden" name="method" value="login"> 用户名：<input type="text" name="name"/><br /> 密码：<input type="password" name="pwd" /><br /> 验证码：<input type="text" name="verifyCode" /><br /> <img src="/tools/VerifyCodeServlet" id="img"/><br /> <a href="javascript:_hyz()">换一张</a> <input type="submit" value="提交" /></form></body></html>配置web.xml文件

<servlet><servlet-name>VerifyCodeServlet</servlet-name><servlet-class>cn.itcast.vcode.servlet.VerifyCodeServlet</servlet-class></servlet><servlet-mapping><servlet-name>VerifyCodeServlet</servlet-name><url-pattern>/VerifyCodeServlet</url-pattern></servlet-mapping>编写后台Servlet

package cn.itcast.test;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import cn.itcast.servlet.BaseServlet;

/**

@author Guozhen_Zhao创建时间：2018年1月28日下午1:41:38

备注：*/
@WebServlet("/loginServlet")
br/>*/
@WebServlet("/loginServlet")

public String login(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//检验验证码
//1. 获取表单中的验证码
String verifyCode = request.getParameter("verifyCode");
//2. 获取图片上的文字
String vcode = (String)request.getSession().getAttribute("vCode");
//3. 检验
System.out.println(verifyCode.equalsIgnoreCase(vcode));

return null;

}
}