Servlet结合jQuery实现异步登录

1.创建登录界面

https://www.cnblogs.com/YorkZhangYang/p/12538576.html

 

2.完成登录验证（原生js实现）

https://www.cnblogs.com/YorkZhangYang/p/12539033.html

 

3.创建LoginServlet（为演示登录过程，未连接数据库验证）

package servlet;

import java.io.IOException;
import java.io.PrintWriter;

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 javax.websocket.Session;

/**
 * Servlet implementation class LoginServlet
 */
@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
        //1.设置获取表单字符集
        request.setCharacterEncoding("utf-8");
        
        //2.设置响应的类型，这里注释掉
        //response.setContentType("text/html;charset=UTF-8");
        
        String name = request.getParameter("username");
        String pwd = request.getParameter("password");
        String code = request.getParameter("validateCode");
        String str="";
        PrintWriter out = response.getWriter();
        
        if(name.equals("")||name==null||pwd.equals("")||pwd==null||code.equals("")||code==null)
        {
            out.print("表单不能为空");
            return;
        }
        
        String scode = (request.getSession().getAttribute("code").toString()).toLowerCase();
        
        boolean IsName = name.equals("admin");
        boolean IsPassword = pwd.equals("123");
        boolean IsCode = code.toLowerCase().equals(scode);
        if(IsName&&IsPassword&&IsCode)
        {
            request.getSession().setAttribute("username", name);
            request.getSession().setAttribute("password", pwd);
            //向客户端响应一个字符串
            str="ok";
            response.getWriter().print(str);
            //response.sendRedirect("adminindex.jsp");
        }
        else
        {
            if(!IsCode)
            {
                str="code";
                response.getWriter().print(str);
            }
            else
            {
                str="namepwd";
                response.getWriter().print(str);
            }
        }
        
        
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}

4.Login.jsp使用jQuery的$.ajax实现异步提交

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>登录界面</title>
    <!-- Bootstrap -->
     
     <link href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css" rel="stylesheet">
    <script src="js/jquery-1.11.1.min.js"></script>
<style>

    .bg{
        height: 600px;
        background-image:url(images/bg.jpg);
        background-size:cover;
    }

    .form{
        padding: 40px;
       margin-top: 175px;
       background: rgba(255,255,255,0.2);
    }

   .footer{
    height: 60px;
    padding-top:20px; 
    font-size: 14px;
    font-weight: bold;
    text-align: center;
   }
   

   
</style>
</head>
<body>

    <div class="page-header">
        <h1>XXXX信息系统登录界面</h1>
      </div>
      <div class="container-fluid">
        <div class="row bg">
          <div class="col-md-offset-6 col-md-4 col-sm-offset-3 col-sm-7 col-xs-offset-2 col-xs-8 col-lg-offset-6 col-lg-3 form">
            <form class="form-horizontal" action="" method="post">
                <div class="form-group">
                  <label for="username" class="col-sm-4 control-label">用户名</label>
                  <div class="col-sm-8">
                    <input type="text" class="form-control" id="username" name="username" placeholder="请输入用户名">
                  </div>
                </div>
                <div class="form-group">
                  <label for="password" class="col-sm-4 control-label">密码</label>
                  <div class="col-sm-8">
                    <input type="password" class="form-control" id="password" name="password" placeholder="请输入密码">
                  </div>
                </div>
                <div class="form-group">
                    <label for="validateCode" class="col-sm-4 control-label">验证码</label>
                    <div class="col-sm-4">
                      <input type="text" class="form-control" id="validateCode" name="validateCode" placeholder="验证码">
                    </div>
                    <div class="col-sm-4">
                        <img id="verifyCode" src="${pageContext.request.contextPath}/VerifyCodeImg" alt="Loading" width="75px" height="35px" onclick="changeCode()">
                      </div>
                  </div>
                <div class="form-group">
                  <div class="col-sm-offset-2 col-sm-10">
                    <div class="checkbox">
                      <label>
                        <input type="checkbox">记住我
                      </label>
                    </div>
                  </div>
                </div>
                <div class="form-group">
                  <div class="col-sm-offset-2 col-sm-10">
                    <button type="button" id="submitBtn" class="btn btn-success"  style="width: 50%;">登录</button>
                  </div>
                </div>
              </form>
              <span style="color: red;" id="tip"></span>
          </div> 
        </div>

        <div class="footer">
                <p>&copy;版权所有：XXXXX学院xx市xx大道XXX号</p>  
                <p>邮编：530001联系邮箱：xxxxxxx@163.com</p> 
        </div>
      </div>

      <script type="text/javascript">
      //验证码更换
      function changeCode() {
          var codeImg=document.getElementById("verifyCode");
          //这里URL后追加随机数，使程序每次访问的都是不同的资源，防止浏览器缓存，即产生不同的验证码
          codeImg.src="/LoginTest/VerifyCodeImg?d="+Math.random();
      }
      
      //表单验证
      //获取要验证的表单对象
        let username = document.getElementById("username");
        let password = document.getElementById("password");
        let validatecode = document.getElementById("validateCode");
        let span = document.getElementById("tip");
        
          username.onblur=function()
          {
            vailidateUserName();
          }

          password.onblur=function()
          {
            validatePassword();
          }

          validatecode.onblur=function()
          {
            validateCode();
          }
        //验证用户名
        function vailidateUserName() {
          //2-12位，字母开头，不能有_$之外的特殊字符
          let reg = /^[a-zA-Z][\w$]{1,11}$/;
          let value= username.value;
          if(!value)
          {
            span.innerHTML = "用户名不能为空";
            return false;
          }
          else if(!reg.test(value))
          {
            span.innerHTML = "用户名2-12位，字母开头，不能有_$之外的特殊字符";
            return false;
          }
          else
          {
            span.innerHTML = "";
            return true;
          }
          
        }

        //验证密码
        function validatePassword()
        {
          let value = password.value;
          
          if(!value)
          {
            span.innerHTML = "密码不能为空";
            return false;
          }
          else
          {
            span.innerHTML = "";
            return true;
          }

        }

        //验证码不能为空
        function validateCode()
        {
          let value  = validatecode.value;
          if(!value)
          {
            span.innerHTML = "验证码不能为空";
            return false;
          }
          else
          {
            span.innerHTML = "";
            return true;
          }
        }

      
      //按钮提交
      $("#submitBtn").click(function(){
          if(vailidateUserName()&&validatePassword()&&validateCode())
          {
            //document.getElementById("loginForm").submit();
          var strName=$("#username").val(); 
          var strPwd=$("#password").val();
          var strCode=$("#validateCode").val();
          console.log(strPwd);
          console.log(strCode);
          $.ajax({
             url:"/LoginTest/LoginServlet",
             dataType:"text",
             type:"post",
             data:{username:strName,password:strPwd,validateCode:strCode},
             beforeSend:function()
             {
               $("#tip").html("正在登录......");
             },
             success:function(data){
               if(data=="ok")
               {
                   //alert("登录成功！");
                   $("#tip").html("登录成功！");
                   window.location.href = "adminindex.jsp";
               }
               if(data=="code")
               {
                 $("#tip").html("验证码错误！");
                 
               }
               if(data=="namepwd")
                {
                   $("#tip").html("用户名或密码错误！");
                  
                }
              
             },
             error:function () {
             console.log("ajax请求数据失败！");
             $("#tip").html("ajax请求数据失败！");
             }
            });
          }
          else
          {
            span.innerHTML = "表单未正确填写";
            return false;
          }
      });
       
      </script>

       <!-- jQuery (Bootstrap 的所有 JavaScript 插件都依赖 jQuery，所以必须放在前边) -->
       <script src="https://cdn.jsdelivr.net/npm/jquery@1.12.4/dist/jquery.min.js"></script>
       <!-- 加载 Bootstrap 的所有 JavaScript 插件。你也可以根据需要只加载单个插件。 -->
       <script src="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/js/bootstrap.min.js"></script>
</body>
</html>

 

5.运行结果

输入用户名admin，密码123，正确输入验证码后，点击登录，成功跳转到adminindex.jsp界面。

 

参考文章：

https://www.cnblogs.com/chy18883701161/p/11431231.html

posted @ 2020-03-21 15:57  YorkShare  阅读(424)  评论(0)  编辑  收藏  举报