问答详情
源自：2-5 数据展示

编译器不报错，就是无法显示数据库里的数据

package com.imooc.servlet;


import java.io.IOException;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.util.ArrayList;

import java.util.List;


import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;


import com.imooc.bean.Message;


/*

 * 列表页面初始化控制

 */

@SuppressWarnings("serial")

public class ListServlet extends HttpServlet {


@Override

protected void doPost(HttpServletRequest req, HttpServletResponse resp)

throws ServletException, IOException {

// TODO Auto-generated method stub

this.doGet(req, resp);

try {

Class.forName("com.mysql.jdbc.Driver");

Connection conn= DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/micro_message","root","8470287");

String sql="select ID,COMMAND,DESCRIPTION,CONTENT from message ";

PreparedStatement statement=conn.prepareStatement(sql);

ResultSet rs=statement.executeQuery(sql);

List<Message>messageList=new ArrayList<Message>();

//System.out.println(messageList.size());

while(rs.next()){

Message message=new Message();

messageList.add(message);

message.setId(rs.getString("ID"));

message.setCommand(rs.getString("COMMAND"));

message.setDescription(rs.getString("DESCRIPTION"));

message.setContent(rs.getString("CONTENT"));

//System.out.println(message);

}

req.setAttribute("messageList", "messageList");

} catch (ClassNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

  @Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp)

throws ServletException, IOException {

 

// TODO Auto-generated method stub

 req.getRequestDispatcher("/WEB-INF/jsp/List.jsp").forward(req, resp);

}

}



这是jsp

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

<%

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

%>

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />

<meta http-equiv="X-UA-Compatible"content="IE=9; IE=8; IE=7; IE=EDGE" />

<title>内容列表页面</title>

<link href="<%= basePath %>resources/css/all.css" rel="stylesheet" type="text/css" />

</head>

<body style="background: #e1e9eb;">

<form action="" id="mainForm" method="post">

<div class="right">

<div class="current">当前位置：<a href="javascript:void(0)" style="color:#6E6E6E;">内容管理</a> &gt; 内容列表</div>

<div class="rightCont">

<p class="g_title fix">内容列表 <a class="btn03" href="#">新 增</a>&nbsp;&nbsp;&nbsp;&nbsp;<a class="btn03" href="#">删 除</a></p>

<table class="tab1">

<tbody>

<tr>

<td width="90" align="right">演示字段1：</td>

<td>

<input type="text" class="allInput" value=""/>

</td>

<td width="90" align="right">演示字段2：</td>

<td>

<input type="text" class="allInput" value=""/>

</td>

                           <td width="85" align="right"><input type="submit" class="tabSub" value="查 询" /></td>

      </tr>

</tbody>

</table>

<div class="zixun fix">

<table class="tab2" width="100%">

<tbody>

<tr>

 <th><input type="checkbox" id="all" /></th>

   <th>序号</th>

   <th>指令名称</th>

   <th>描述</th>

   <th>操作</th>

</tr>

<c:forEach items="${messageList}" var="message" varStatus="status">

<tr  <c:if test="${status.index % 2 != 0}">style='background-color:#ECF6EE;'</c:if>>

<td><input type="checkbox"  name="id" value="${message.id}"/></td>

<td>${status.index + 1}</td>

<td>${message.command}</td>

<td>${message.description}</td>

<td>

<a href="#">修改</a>&nbsp;&nbsp;&nbsp;

<a href="${basePath}DeleteOneServlet.action?id=${message.id}">删除</a>

</td>

</tr>

</c:forEach>

</tbody>

</table>

<div class='page fix'>

共 <b>4</b> 条

<a href='###' class='first'>首页</a>

<a href='###' class='pre'>上一页</a>

当前第<span>1/1</span>页

<a href='###' class='next'>下一页</a>

<a href='###' class='last'>末页</a>

跳至&nbsp;<input type='text' value='1' class='allInput w28' />&nbsp;页&nbsp;

<a href='###' class='go'>GO</a>

</div>

</div>

</div>

</div>

   </form>

</body>

</html>

 一晚上都没调好，这是为什么

提问者：我真的不知道要取什么名字 2016-08-21 02:00

个回答

  • 摩诃迦叶
    2016-08-21 15:52:44

    while(rs.next()){

    Message message=new Message();

    message.setId(rs.getString("ID"));

    message.setCommand(rs.getString("COMMAND"));

    message.setDescription(rs.getString("DESCRIPTION"));

    message.setContent(rs.getString("CONTENT"));

    //System.out.println(message);

    messageList.add(message);

    }

    改成这样。  你要先给message设置完熟悉再加到list中才有属性值啊

    0