问题遇到的现象和发生背景
问题相关代码，请勿粘贴截图
运行结果及报错内容
我的解答思路和尝试过的方法
我想要达到的结果
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page import="entity.D_Entity" %>
<%@ page import="java.util.List" %>
<%@ page import="dao.D_Dao" %><%--
Created by IntelliJ IDEA.
User: Lenovo
Date: 2022/3/31
Time: 15:34
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<style>
table{
border: 1px black solid;
}
td{
border: 2px red solid;
width: 50px;
height: 20px;
}
</style>
<body>
<table >
<tr >
<td>编号</td>
<td>机名</td>
<td>CPU</td>
<td>主板</td>
<td>内存</td>
<td>显卡</td>
<td>硬盘</td>
<td>操作</td>
</tr>
<c:forEach items="${arrayList}" var="s" varStatus="ss">
<c:if test="$ss.count%2!=0" >
<tr style="" >
<td>${s.D_ID}</td>
<td>${s.D_NAME}</td>
<td>${s.D_CPU}</td>
<td>${s.D_BOARD}</td>
<td>${s.D_MEMORY}</td>
<td>${s.D_CARD}</td>
<td>${s.D_HARBDISK}</td>
<td > <a href="DelDIY_Servlet?id=${s.D_ID}">删除</a></td>
</tr>
</c:if>
</c:forEach>
<tr style="border: black 1px solid">
<td>1</td>
<td>2</td>
<td>3</td>
<td>4</td>
<td>5</td>
<td>6</td>
<td>7</td>
<td> 8</td>
</tr>
</table>
</body>
</html>
package action;
import dao.D_Dao;
import entity.D_Entity;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
public class QueryDIY_Servlet extends HttpServlet {
protected void service(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws ServletException, IOException {
D_Dao d_dao=new D_Dao();
ArrayList<D_Entity> arrayList = d_dao.QueryD();
httpServletRequest.setAttribute("arrayList",arrayList);
httpServletRequest.getRequestDispatcher("DIY_All.jsp").forward(httpServletRequest,httpServletResponse);
}
}
public class D_Dao {
public static ArrayList<D_Entity> QueryD(){
ArrayList<D_Entity> arrayList=new ArrayList<D_Entity>();
D_Entity d_entity=null;
Connection connection=BaseDao.get_Connection();
PreparedStatement preparedStatement1=null;
ResultSet resultSet=null;
try {
preparedStatement1=connection.prepareStatement("select * from DIY_INFO order by ID desc ");
resultSet=preparedStatement1.executeQuery();
while (resultSet.next()){
d_entity=new D_Entity(resultSet.getInt("D_ID"),resultSet.getString("D_NAME"),resultSet.getString("D_CPU"),resultSet.getString("D_BOARD"),resultSet.getString("D_MEMORY"),resultSet.getString("D_CARD"),resultSet.getString("D_HARBDISK"));
arrayList.add(d_entity);
}
} catch (SQLException e) {
e.printStackTrace();
}
finally {
BaseDao.closeconnection(connection,preparedStatement1,resultSet);
}
return arrayList;
}
