使用AJAX（包含正则表达式）验证用户登录的步骤

(编辑：jimmy 日期: 2024/5/9 浏览：3 次 )

我们来分一下步骤吧：

1.HTML代码，页面先写出来；

2.正则表达式验证输入的用户名密码是否正确，失去焦点验证

3.Ajax异步提交

4.servlet这是后台处理代码获取数据并对比响应，然后跳转成功页面

效果图：

结构：

代码如下：

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<script type="text/javascript" src="/UploadFiles/2021-04-02/jQuery.js">

servlet代码：



package com.chaz.servlet;
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;
public class AJAXServlet extends HttpServlet {
 public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 doPost(request, response);
 }
 public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 response.setContentType("text/html;charset=utf-8");
 request.setCharacterEncoding("utf-8");
 PrintWriter out = response.getWriter();
 
 String name = "ZhangSan";
 String pwd = "Zhang123456";
 
 String ajaxName = request.getParameter("name");
 String ajaxPwd = request.getParameter("pwd");
 System.out.println(ajaxName+":"+ajaxPwd);
 if(name.equals(ajaxName)&&pwd.equals(ajaxPwd)){
 out.print("ok");
 }else{
 out.print("Error");
 }
 out.flush();
 out.close();
 }
}


web.xml:



<"1.0" encoding="UTF-8""3.0"
 xmlns="http://java.sun.com/xml/ns/javaee"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
 <servlet>
 <description>This is the description of my J2EE component</description>
 <display-name>This is the display name of my J2EE component</display-name>
 <servlet-name>AJAXServlet</servlet-name>
 <servlet-class>com.chaz.servlet.AJAXServlet</servlet-class>
 </servlet>

 <servlet-mapping>
 <servlet-name>AJAXServlet</servlet-name>
 <url-pattern>/AJAXServlet</url-pattern>
 </servlet-mapping>

</web-app>


跳转成功页面就这个"color: #ff0000">总结
以上所述是小编给大家介绍的使用AJAX（包含正则表达式）验证用户登录的步骤,希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对网站的支持！

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