| 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="http://www.admin5.com/article/20201216/JS/jQuery.js"></script>
 <style type="text/css">
 table {
 width: 360px;
 height: 45px:
 text-align: center;
 margin-top: 120px;
 border-collapse: collapse;
 }
 input {width: 280px;
 height: 30px;
 }
 </style>
 </head>
 <body>
 <form action="#" method="post">
 <center>
 <table>
 <tr>
 <td>用户名:</td>
 <td><input type="text"
 onblur="verifyName()" /></td>
 </tr>
 <tr>
 <td>密码:</td>
 <td><input type="text"
 onblur="verifyPwd()" /></td>
 </tr>
 <tr>
 <td colspan="3"><input
 type="button" value="提交登录验证" /></td>
 </tr>
 </table>
 </center>
 </form>
 <script type="text/javascript">
 function verifyName() {
 //用户名校验
 var verifyName = document.getElementById("username").value;
 var name = /^[A-Z][0-9A-Za-z_][a-zA-Z0-9_]{5,19}$/; // 大写字母开头 6-20位字符(不允许有符号但是允许有_)
 if (!name.test(verifyName)) {
 //$("#username").after("<span>大写字母开头6-20位字符(不允许有符号但是允许有_)</span>");
 $("#username").css("border-color", "red");
 return false;
 } else {
 return true;
 }
 }
 function verifyPwd() {
 //密码
 var verifyPwd = document.getElementById("mypwd").value;
 var pwd = /^[A-Z][A-Za-z0-9]w{7,14}.{1,20}$/; //大写开头 数字字母符号混合 8-15位
 if (!pwd.test(verifyPwd)) {
 $("#username").css("border-color", "red");
 return false;
 } else {
 return true;
 }
 }
 
 $(function() {
 $(":button").on("click", function() {
 $.ajax({
 type : "post",
 url : "AJAXServlet",
 data : {
 name : $("#username").val(),
 pwd : $("#mypwd").val()
 },
 dataType : "text",
 success : function(data) {
 if (data == "ok") {
 window.location.href = "show.jsp";
 } else {
 alert("登录失败!");
 $("#mypwd").val("");
 $("#username").focus().select();
 }
 }
 });
 });
 });
 </script>
 </body>
 </html>
 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: <?xml version="1.0" encoding="UTF-8"?><web-app version="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 ">
 <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: <body> 登录成功!</body> 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脚本之家网站的支持! (编辑:宣城站长网) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |