package com.swift;

//这里导入的包是java.sql.Connection而不是com.mysql.jdbc.Connection

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import java.util.ArrayList;

import java.util.List;

public class TestJDBC {

    public static void main(String[] args) {

        Connection conn=null;

        Statement st=null;

        ResultSet rs=null;

        try {

            //1、装载驱动

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

        } catch (ClassNotFoundException e) {

            e.printStackTrace();

        }

        try {

            //2、链接数据库，使用com.mysql.jdbc.Connection包会出错

            List<User> list=new ArrayList<User>();

            conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/sw_database?user=root&password=root");

            //3、创建连接语句

            st=conn.createStatement();

            //4、执行ＳＱＬ语句获得结果集

            rs=st.executeQuery("select * from sw_user");

            //5、循环获得数据库字段生成对象

            while(rs.next()) {

                int id=rs.getInt("id");

                String username=rs.getString("username");

                String password=rs.getString("password");

                User user=new User(id,username,password);

                list.add(user);

            }

            //6、遍历对象列表

            for(User user:list) {

                System.out.println(user.toString());

            }

        } catch (SQLException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }finally {

            //7、关闭结果集

            try {

                if(rs!=null) {

                   rs.close();

                }

            } catch (SQLException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

            //7、关闭连接语句

            try {

                if(st!=null) {

                   st.close();

                }

            } catch (SQLException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

            //7、关闭数据库连接

            try {

                if(conn!=null) {

                    conn.close();

                }

            } catch (SQLException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

        }

    }

}

package com.swift.jdbc;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.util.ArrayList;

import java.util.List;

import org.apache.commons.beanutils.BeanUtils;

import com.swift.bean.User;

public class JDBC_Demo {

    public static void main(String[] args) throws Exception {

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

        String user="root";

        String password="root";

        String url="jdbc:mysql://127.0.0.1:3306/swift_db";

        Connection con=DriverManager.getConnection(url, user, password);

        PreparedStatement sql = con.prepareStatement("select * from user");

        ResultSet result = sql.executeQuery();

        List<User> list =new ArrayList<>();

        while(result.next()) {

            int uid=result.getInt("uid");

            String uname=result.getString("uname");

            String upassword=result.getString("upassword");

            Class clazz=Class.forName("com.swift.bean.User");

            User userObj=(User) clazz.newInstance();

            BeanUtils.setProperty(userObj,"uid",uid);

            BeanUtils.setProperty(userObj,"uname",uname);

            BeanUtils.setProperty(userObj,"upassword",upassword);

            list.add(userObj);

        }

        System.out.println(list);

    }

}