JasperException
Show.jsp
<%@ page import="java.sql.Connection" %>
<%@ page import="com.sys.util.DBConnectionPool" %>
<%@ page import="java.sql.PreparedStatement" %>
<%@ page import="java.sql.ResultSet" %>
<%@ page import="com.sys.entity.User" %><%--
Created by IntelliJ IDEA.
User: liruyuan
Date: 2021/5/20
Time: 21:55
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
<link rel="stylesheet" type="text/css" href="${pageContext.request.contextPath}/css/CShow.css" />
</head>
<body>
<%
Connection conn = DBConnectionPool.getInstance().getConn();
PreparedStatement ps;
ResultSet rs;
User user= (User) session.getAttribute("user");
ps = conn.prepareStatement("select * from login where username=?");
ps.setString(1,user.getUsername());
rs = ps.executeQuery();
if(rs.next()){
user = new User();
user.setUsername(rs.getString("username"));
user.setPassword(rs.getString("password"));
user.setSchool(rs.getString("school"));
user.setRole(rs.getString("role"));
user.setName(rs.getString("name"));
}
%>
<div id="divmain">
<div id="divform">
<form>
<div id="div1">
<div id="circle"></div>
<input type="button" class="button" value="修改头像"/>
</div>
<div id="div2">
<table>
<tr>
<th class="th1"><span>姓名</span></th>
<th class="th2"><%=user.getName() %></th>
</tr>
<tr>
<th class="th1"><span>用户名</span></th>
<th class="th2"><%=user.getUsername() %></th>
</tr>
<tr>
<th class="th1"><span>工作单位</span></th>
<th class="th2"><%=user.getSchool() %></th>
</tr>
<tr>
<th class="th1"><span>角色</span></th>
<th class="th2"><%=user.getRole() %></th>
</tr>
</table>
</div>
</form>
</div>
</div>
</body>
</html>
每次删除完浏览器的历史记录，就出现这个问题，然后刷新一下就没事了，怎么解决
应该是数据库连接失败了，先打印conn出来看看。