1.新建配置jdbc数据源，具体过程省略

2.新建实体表

3.新建项目

（1）新建数据库连接工具类JDBCUtils，通过配置数据源获取连接

package com.landingbj.util;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.ResultSetMetaData;

import java.sql.SQLException;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import javax.naming.InitialContext;

import javax.naming.NamingException;

import javax.sql.DataSource;

import org.apache.commons.lang.StringUtils;

public class JDBCUtils {

    // 三剑客

    Connection con = null;// 连接对象

    PreparedStatement pstmt = null;// 语句对象

    ResultSet rs = null;// 结果集对象

    public Connection getConnection() throws ClassNotFoundException,

            SQLException {

        try {

            InitialContext cxt = new InitialContext();

            DataSource ds = (DataSource) cxt.lookup("test");

            con = ds.getConnection();

        } catch (NamingException e) {

            e.printStackTrace();

        }

        return con;

    }

    public void close(ResultSet rs, PreparedStatement pstmt, Connection con) {

        try {

            if (rs != null)

                rs.close();

            if (pstmt != null)

                pstmt.close();

            if (con != null)

                con.close();

        } catch (SQLException e) {

            // TODO: handle exception

            e.printStackTrace();

        }

    }

    public int execUpdate(String sql, Object[] params) {

        try {

            this.getConnection();// 获得连接对象

            this.pstmt = this.con.prepareStatement(sql);// 获得预设语句对象

            if (params != null) {

                // 设置参数列表

                for (int i = 0; i < params.length; i++) {

                    // 因为问号参数的索引是从1开始，所以是i+1，将所有值都转为字符串形式，好让setObject成功运行

                    this.pstmt.setObject(i + 1, params[i] + "");

                }

            }

            return this.pstmt.executeUpdate(); // 执行更新，并返回影响行数

        } catch (Exception e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        } finally {

            this.close(this.rs, this.pstmt, this.con);

        }

        return 0;

    }

    public List<Map<String, Object>> execQuery(String sql, Object[] params) {

        try {

            this.getConnection();// 获得连接对象

            this.pstmt = this.con.prepareStatement(sql);// 获得预设语句对象

            if (params != null) {

                // 设置参数列表

                for (int i = 0; i < params.length; i++) {

                    // 因为问号参数的索引是从1开始，所以是i+1，将所有值都转为字符串形式，好让setObject成功运行

                    this.pstmt.setObject(i + 1, params[i] + "");

                }

            }

            // 执行查询

            ResultSet rs = pstmt.executeQuery();

            List<Map<String, Object>> al = new ArrayList<Map<String, Object>>();

            // 获得结果集元数据（元数据就是描述数据的数据，比如把表的列类型列名等作为数据）

            ResultSetMetaData rsmd = rs.getMetaData();

            // 获得列的总数

            int columnCount = rsmd.getColumnCount();

            // 遍历结果集

            while (rs.next()) {

                Map<String, Object> hm = new HashMap<String, Object>();

                for (int i = 0; i < columnCount; i++) {

                    // 根据列索引取得每一列的列名,索引从1开始

                    String columnName = StringUtils.upperCase(rsmd

                            .getColumnName(i + 1));

                    // 根据列名获得列值

                    Object columnValue = rs.getObject(columnName);

                    // 将列名作为key，列值作为值，放入 hm中，每个 hm相当于一条记录

                    hm.put(columnName, columnValue);

                }

                // 将每个 hm添加到al中, al相当于是整个表，每个 hm是里面的一条记录

                al.add(hm);

            }

            return al;

        } catch (Exception e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        } finally {

            this.close(this.rs, this.pstmt, this.con);

        }

        return null;

    }

}

（2）students实体类

package com.landingbj.entity;

public class Students {

private int stuId;

    private String name;

    private String age;

public int getStuId() {

return stuId;

}

public void setStuId(int stuId) {

this.stuId = stuId;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getAge() {

return age;

}

public void setAge(String age) {

this.age = age;

}

}

（3）新建StudentServlet

package com.landingbj.servlet;

import java.io.IOException;

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.landingbj.entity.Students;

import com.landingbj.service.StudentService;

public class StudentServlet extends HttpServlet{

 private static final long serialVersionUID = 1L;

 public StudentServlet() {

        super();

    }

 public void destroy(){

 super.destroy();

 }

 public void doGet(HttpServletRequest req,HttpServletResponse res)throws ServletException, IOException {

 req.setCharacterEncoding("UTF-8");

 StudentService studentService = new StudentService();

     List<Students> students = studentService.getAllStudents();

     System.out.println(students);

     req.setAttribute("students", students);

     req.getRequestDispatcher("/studentslist.jsp").forward(req, res);

 }

}

（4）新建StudentService

package com.landingbj.service;

import java.util.List;

import com.landingbj.dao.StudentDao;

import com.landingbj.entity.Students;

public class StudentService {

 public StudentService(){

    }

    static StudentDao stuDao = new StudentDao();

    public List<Students> getAllStudents(){

        return stuDao.queryStudents();

    }  

}

（5）新建StudentDao类

package com.landingbj.dao;

import java.util.ArrayList;

import java.util.List;

import java.util.Map;

import org.apache.commons.lang.StringUtils;

import com.landingbj.entity.Students;

import com.landingbj.util.JDBCUtils;

public class StudentDao {

JDBCUtils jdbcUtils = new JDBCUtils();

    private static final String[] SQL_QUERY_FIELDS = {"STUID","NAME","AGE"};

    private static final String SQL_QUERY = "select "+StringUtils.join(SQL_QUERY_FIELDS,",")+" from students;";

public List<Students> queryStudents() {

System.out.println("+++++++++++++++");

ArrayList<Students> students = new ArrayList<Students>();

        List<Map<String, Object>> result = jdbcUtils.execQuery(SQL_QUERY, null);

        System.out.println(result);

        for(int i=0;i<result.size();i++){

         Students student = new Students();

            Map<String,Object> map = result.get(i); 

            student.setStuId((Integer) map.get(SQL_QUERY_FIELDS[0]));

            student.setName(map.get(SQL_QUERY_FIELDS[1]).toString());

            student.setAge(map.get(SQL_QUERY_FIELDS[2]).toString());

            students.add(student);

        }

        return students;

}

}

（6）JSP页面以及web.xml

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

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

<%

String path = request.getContextPath();

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

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<base href="<%=basePath%>">

<title>studentslist</title>

<meta http-equiv="pragma" content="no-cache">

<meta http-equiv="cache-control" content="no-cache">

<meta http-equiv="expires" content="0">

<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

<meta http-equiv="description" content="This is my page">

<!--

    <link rel="stylesheet" type="text/css" href="styles.css">

    -->

</head>

<body>

    <table>

        <tr>

            <th>id</th>

            <th>姓名</th>

            <th>年龄</th>

        </tr>

        <c:forEach items="${students}" var="students">

            <tr>

                <td>${students.stuId}</td>

                <td>${students.name}</td>

                <td>${students.age}</td>

            </tr>

        </c:forEach>

    </table>

</body>

</html>

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">

  <servlet>

    <servlet-name>StudentServlet</servlet-name>

    <servlet-class>com.landingbj.servlet.StudentServlet</servlet-class>

  </servlet>

  <servlet-mapping>

    <servlet-name>StudentServlet</servlet-name>

    <url-pattern>/studentServlet</url-pattern>

  </servlet-mapping>

  <welcome-file-list>

    <welcome-file>studentslist.jsp</welcome-file>

  </welcome-file-list>

</web-app>