JDBC把数据存到集合之ResultSet

package com.czie.jdbc;


import com.czie.pojo.Account;
import org.junit.Test;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

/**
 * JDBC API 详解：ResultSet
 */
public class JDBCDemo5_ResultSet {

    /**
     * 执行DQL
     * @throws Exception
     */
    @Test
    public void testResultSet() throws  Exception {
        //1. 注册驱动
        //Class.forName("com.mysql.jdbc.Driver");
        //2. 获取连接：如果连接的是本机mysql并且端口是默认的 3306 可以简化书写
        String url = "jdbc:mysql:///lps?useSSL=false";
        String username = "root";
        String password = "1234";
        Connection conn = DriverManager.getConnection(url, username, password);

        //3.定义sql
        String sql="select * from account";
        //获取statement
        Statement stmt = conn.createStatement();
        //执行sql
        ResultSet rs = stmt.executeQuery(sql);
        //6.处理结果遍历rs数据
        //6.1光标向下移动一行 并且去判断当前行是否有数据
        /*while (rs.next()){
            //6.2获取数据 getXXX();
            int id = rs.getInt(1);
            String name = rs.getString(2);
            double money = rs.getDouble(3);

            System.out.println(id);
            System.out.println(name);
            System.out.println(money);
            System.out.println("=========");

        }*/
        while (rs.next()){
            //6.2获取数据 getXXX();
            int id = rs.getInt("id");
            String name = rs.getString("name");
            double money = rs.getDouble("money");

            System.out.println(id);
            System.out.println(name);
            System.out.println(money);
            System.out.println("=========");

        }

        //7.释放资源
        rs.close();
        stmt.close();
        conn.close();
    }
    /**
     * 查询account账户表数据，封装为Account对象中，并且存储到ArrayList集合中
     * 1. 定义实体类Account
     * 2. 查询数据，封装到Account对象中
     * 3. 将Account对象存入ArrayList集合中
     *
     * @throws Exception
     */
    @Test
    public void testResultSet2() throws  Exception {
        //1. 注册驱动
        //Class.forName("com.mysql.jdbc.Driver");
        //2. 获取连接：如果连接的是本机mysql并且端口是默认的 3306 可以简化书写
        String url = "jdbc:mysql:///lps?useSSL=false";
        String username = "root";
        String password = "1234";
        Connection conn = DriverManager.getConnection(url, username, password);

        //3.定义sql
        String sql="select * from account";
        //获取statement
        Statement stmt = conn.createStatement();
        //执行sql
        ResultSet rs = stmt.executeQuery(sql);
        //6.处理结果遍历rs数据
        List<Account> list = new ArrayList<>();

        while (rs.next()){
            Account account=new Account();
            //6.2获取数据 getXXX();
            int id = rs.getInt("id");
            String name = rs.getString("name");
            double money = rs.getDouble("money");

            account.setId(id);
            account.setName(name);
            account.setMoney(money);

            //存入集合
            list.add(account);
        }
        System.out.println(list);

        //7.释放资源
        rs.close();
        stmt.close();
        conn.close();
    }
}

package com.czie.pojo;

public class Account {
    private int id;
    private String name;
    private double money;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getMoney() {
        return money;
    }

    public void setMoney(double money) {
        this.money = money;
    }

    @Override
    public String toString() {
        return "Account{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", money=" + money +
                '}';
    }
}