删除问题！！！！紧急

<%@ page import="java.util.Map" %>
<%@ page import="java.util.List" %>
<%@ page import="java.util.HashMap" %>
<%@ page import="com.syc.service.CourseServiceImpl" %>
<%@ page language="java" contentType="text/html; charset=utf-8"
         pageEncoding="utf-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<script src="<%=basePath%>/js/jquery-3.2.1.js"></script>
<!DOCTYPE html>
<html>
<head>
    <base href="<%=basePath%>">
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <title>管理员查询</title>
</head>
<body>
<center>
    <h1>管理员查询</h1>
    <hr>
    <table cellspacing="0px" cellpadding="0px" border="1px" width="600px">
        <thead>
        <tr>
            <th>用户名</th>
            <th>密码</th>
            <th>类型</th>
            <th>操作</th>
        </tr>
        </thead>
        <tbody id="cont">
        <c:forEach items="${userList}" var="user">
            <tr>
                <td>${user.username}</td>
                <td>${user.password}</td>
                <td>
                        ${user.type}
                </td>
                <td><a id="delete" data-value="${user.username}" onclick="shanchu(this)" >删除</a></td>
            </tr>
        </c:forEach>
 
        </tbody>
    </table>
 
</center>
</body>
<script type="text/javascript">
    function shanchu(e){
        // function refresh () {
        var value=e.getAttribute("data-value");
        alert(value);
        $.ajax({
            url:"<%=basePath%>/DeleteServlet",
            type:"post",
            data:{
                username:value
            },
            dataType:"json",
            success:function (result) {
                var list = eval(result);
                console.log(list);
                var content = null;
                if(list != null){
                    for(var i in list){
                        var username = list[i].username;
                        var password = list[i].password;
                        var type = list[i].type;
                        content = content + "<tr><td>" + username + "</td><td>" + password + "</td><td>" + type + "</td></tr>";
 
                    }
                    $("#cont").remove();
                    $("#cont").html(content);
                }
            }
        });
    }
</script>
 
</html>

package com.syc.servlet;
 
import com.syc.service.CourseServiceImpl;
import org.json.JSONArray;
import org.json.JSONObject;
 
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 java.io.IOException;
import java.util.List;
import java.util.Map;
 
@WebServlet(name = "DeleteServlet")
public class DeleteServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
 
    }
 
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("删除启动");
        CourseServiceImpl courseServiceImpl = new CourseServiceImpl();
        List<Map<String,Object>> userList = courseServiceImpl.getAllUsers();
        System.out.println("1"+userList);
        String username = request.getParameter("username");
        System.out.println(username);
        courseServiceImpl.delUser(username);
        System.out.println("删除完毕");
        System.out.println("2"+userList);
        JSONArray jsonArray = new JSONArray(userList);
        response.getOutputStream().write(jsonArray.toString().getBytes("utf-8"));
    }
}

public void delUser(String username) {
 
    for(Map<String,Object> map:usersTable){
        if(username.equals(map.get("username"))){
            usersTable.remove(map);
            break;
        }
    }
}

报错及代码如上，可以删除管理员但是得重新刷新下页面。求解

落枫不知秋 2018-12-13

源自：项目：商品展示及购物车 5-3 作业题

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2回答

提问者落枫不知秋 2018-12-13 17:42:49

5-3的作业，通过ajax删除管理员账号，我可以删除，但是必须刷新下才能显示。然后错误提示是这样的、

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好帮手慕阿满 #1

另外同学的控制台有报错吗？删除启动和删除完毕有输出吗？另外使用ajax还需要刷新应该是同学ajax的括号有问题，建议同学检查一下。祝：学习愉快~

2018-12-13 19:11:14
提问者落枫不知秋回复好帮手慕阿满 #2

报错我发了图片在上面的。有输出的啊，我在检查一下。。

2018-12-13 19:50:35