代码运行说服务器有错？

<%@ page language="java" import="java.util.*,javabean.Bean_User" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>

<div>
<form action="./Ser_User?type=insert" method="post">
      用户ID<input type="text" name="id" style="width:10%;height:5%">
      用户名<input type="text" name="name" style="width:10%;height:5%">
      密码<input type="text" name="password" style="width:10%;height:5%">
      年龄<input type="text" name="age" style="width:10%;height:5%">
      生日<input type="text" name="date" style="width:10%;height:5%">
   <button type="submit" class="btn btn-default">添加用户</button>
</form>
</div>
<br>

<div>
<form action="./Ser_User?type=update" method="post">
      用户ID<input type="text" name="id" style="width:10%;height:5%">
      用户名<input type="text" name="name" style="width:10%;height:5%">
      密码<input type="text" name="password" style="width:10%;height:5%">
      年龄<input type="text" name="age" style="width:10%;height:5%">
      生日<input type="text" name="date" style="width:10%;height:5%">
    <button type="submit" class="btn btn-default">修改信息</button>
</form>
</div>
<br>

<div>
<form action="./Ser_User?type=find" method="post">
    用户ID<input type="text" name="id" style="width:10%;height:5%">
    <button type="submit" class="btn btn-default">查询用户</button>
</form>
</div>
<br>

<div>
<form action="./Ser_User?type=delete" method="post">
    用户ID<input type="text" name="id" style="width:10%;height:5%">
    <button type="submit" class="btn btn-default">删除用户</button>
</form>
</div>
<br>

<!-- 遍历userList集合，输出所有用户  -->
<%
    List<Bean_User> userList = (ArrayList<Bean_User>)request.getAttribute("userList");
%>
    <div class="container">
    <div class="row">
    <div class="col-md-8 col-md-offset-2">
    <table class="table  table-striped table-bordered table-hover">
    <thead>
    <tr><th>用户ID</th><th>用户名</th><th>密码</th><th>年龄</th><th>生日</th></tr>
    </thead>    
    
    <%
    for(Bean_User user : userList){
    %>
    
    <tr>
    <td><%=user.getId() %></td>
    <td><%=user.getName() %></td>
    <td><%=user.getPassword() %></td>
    <td><%=user.getAge() %></td>
    <td><%=user.getBirth() %></td>
    </tr>
    
    <%
    }
    %>    
    </table>
    </div>
    </div>
    </div>
    

报错的内容看一下