JavaWeb-查询列表

  1. 前端页面
<%@ page contentType="text/html;charset=UTF-8" language="java" %>

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

<!DOCTYPE html>
<!-- 网页使用的语言 -->
<html lang="zh-CN">
<head>
    <!-- 指定字符集 -->
    <meta charset="utf-8">
    <!-- 使用Edge最新的浏览器的渲染方式 -->
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <!-- viewport视口:网页可以根据设置的宽度自动进行适配,在浏览器的内部虚拟一个容器,容器的宽度与设备的宽度相同。
    width: 默认宽度与设备的宽度相同
    initial-scale: 初始的缩放比,为1:1 -->
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3个meta标签*必须*放在最前面,任何其他内容都*必须*跟随其后! -->
    <title>用户信息管理系统</title>

    <!-- 1. 导入CSS的全局样式 -->
    <link href="css/bootstrap.min.css" rel="stylesheet">
    <!-- 2. jQuery导入,建议使用1.9以上的版本 -->
    <script src="js/jquery-2.1.0.min.js"></script>
    <!-- 3. 导入bootstrap的js文件 -->
    <script src="js/bootstrap.min.js"></script>
    <style type="text/css">
        td, th {
            text-align: center;
        }
    </style>
</head>
<body>
<div class="container">
    <h3 style="text-align: center">用户信息列表</h3>
    <table border="1" class="table table-bordered table-hover">
        <tr class="success">
            <th>编号</th>
            <th>姓名</th>
            <th>性别</th>
            <th>年龄</th>
            <th>籍贯</th>
            <th>QQ</th>
            <th>邮箱</th>
            <th>操作</th>
        </tr>

        <c:forEach items="${users}" var="user" varStatus="s">
            <tr>
                <td>${s.count}</td>
                <td>${user.name}</td>
                <td>${user.gender}</td>
                <td>${user.age}</td>
                <td>${user.address}</td>
                <td>${user.qq}</td>
                <td>${user.email}</td>
                <td><a class="btn btn-default btn-sm" href="update.html">修改</a>&nbsp;<a class="btn btn-default btn-sm" href="">删除</a></td>
            </tr>

        </c:forEach>


        <tr>
            <td colspan="8" align="center"><a class="btn btn-primary" href="add.html">添加联系人</a></td>
        </tr>
    </table>
</div>
</body>
</html>

  1. servlet层
package com.gaopeng.web.servlet;

import com.gaopeng.domain.User;
import com.gaopeng.service.impl.UserServiceImpl;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.util.List;

@WebServlet(name = "UserServlet", value = "/userListServlet")
public class UserServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //调用service层 完成用户表的查询操作
        UserServiceImpl userServiceimpl = new UserServiceImpl();
        List<User> userList = userServiceimpl.getUserList();
        //将查询到的数据存入request域中
        request.setAttribute("users",userList);
        //转发到list.jsp页面
        //转发是内部跳转 不需要添加虚拟目录
        request.getRequestDispatcher("/list.jsp").forward(request,response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request,response);
    }
}

  1. service层
package com.gaopeng.service.impl;

import com.gaopeng.dao.UserDao;
import com.gaopeng.dao.impl.UserDaoImpl;
import com.gaopeng.domain.User;
import com.gaopeng.service.UserService;

import java.util.List;

public class UserServiceImpl implements UserService {
    private UserDaoImpl userDao = new UserDaoImpl();
    @Override
    public List<User> getUserList() {
        return userDao.getUserList();
    }
}

  1. dao层
package com.gaopeng.dao.impl;

import com.gaopeng.dao.UserDao;
import com.gaopeng.domain.User;
import com.gaopeng.util.JDBCUtils;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;

import java.util.List;

public class UserDaoImpl implements UserDao {
    private static JdbcTemplate jdbcTemplate = new JdbcTemplate(JDBCUtils.getDataSource());
    @Override
    public List<User> getUserList() {
        List<User> users = jdbcTemplate.query("select * from user",new BeanPropertyRowMapper<User>(User.class));
        return users;
    }
}

  1. domain层
package com.gaopeng.domain;

import lombok.Data;

@Data
public class User {
    private int id;
    private String name;
    private String gender;
    private int age;
    private String address;
    private String qq;
    private String email;
}

  1. 工具类
package com.gaopeng.util;

import com.alibaba.druid.pool.DruidDataSourceFactory;

import javax.sql.DataSource;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;

/**
 * JDBC工具类 使用Durid连接池
 */
public class JDBCUtils {

    private static DataSource ds ;

    static {

        try {
            //1.加载配置文件
            Properties pro = new Properties();
            //使用ClassLoader加载配置文件,获取字节输入流
            InputStream is = JDBCUtils.class.getClassLoader().getResourceAsStream("druid.properties");
            pro.load(is);

            //2.初始化连接池对象
            ds = DruidDataSourceFactory.createDataSource(pro);

        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 获取连接池对象
     */
    public static DataSource getDataSource(){
        return ds;
    }


    /**
     * 获取连接Connection对象
     */
    public static Connection getConnection() throws SQLException {
        return  ds.getConnection();
    }
}

  1. 配置文件
driverClassName=com.mysql.cj.jdbc.Driver
url=jdbc:mysql:///day17?serverTimezone=UTC&useUnicode=true&characterEncoding=utf8
username=root
password=123456
initialSize=5
maxActive=10
maxWait=3000
  1. 问题
    1. MySQL 如果是8.0的版本 需要使用com.mysql.cj.jdbc.Driver
    2. 连接数据库需要设置 时区 编码格式 jdbc:mysql:///day17?serverTimezone=UTC&useUnicode=true&characterEncoding=utf8
posted @ 2021-11-28 22:29  争取做百分之一  阅读(227)  评论(0)    收藏  举报