先创建一个class

package cn.itcast.jdbc;
//创建toString
public class EMP {

    private String name;
    private String pwd;
    private String sex;
    private String home;
    private String info;
    @Override
    public String toString() {
        return "EMP{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", pwd='" + pwd + '\'' +
                ", sex='" + sex + '\'' +
                ", home='" + home + '\'' +
                ", info='" + info + '\'' +
                '}';
    }

    private int id;

    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 String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public String getHome() {
        return home;
    }

    public void setHome(String home) {
        this.home = home;
    }

    public String getInfo() {
        return info;
    }

    public void setInfo(String info) {
        this.info = info;
    }


}

JDBC 实现查询

package cn.itcast.jdbc;

import java.sql.*;
import java.util.ArrayList;
import java.util.List;


public class Dem5 {

    public static void main(String[] args){
        List<EMP> list=new Dem5().findAll();
        System.out.println(list);

    }



    //查询所有 emp
    public List<EMP> findAll() {
Connection conn=null;
Statement stmt=null;
ResultSet rs=null;
List<EMP> list=null;

        try {
            //注册驱动
            Class.forName("com.mysql.jdbc.Driver");
            //获取连接
              conn = DriverManager.getConnection("jdbc:mysql:///jdbctest", "root", "root");
            //定义sql
            String sql = "select * from user";
            //获取执行sql的对象
            stmt = conn.createStatement();
            //执行sql
             rs = stmt.executeQuery(sql);

            //遍历接结果集，封装对象，装载集合
            EMP emp=null;
            list=new ArrayList<EMP>();
            while (rs.next()) {

                //要跟数据库的列名一样

                int id = rs.getInt("id");
                String name = rs.getString("name");
                String pwd = rs.getString("pwd");
                String sex = rs.getString("sex");
                String home = rs.getString("home");
                String info = rs.getString("info");
                //创建emp对象并赋值
                emp=new EMP();
                emp.setId(id);
                emp.setName(name);
                emp.setPwd(pwd);
                emp.setSex(sex);
                emp.setHome(home);
                emp.setInfo(info);

                //装载集合
                list.add(emp);




            }


        } catch (ClassNotFoundException e) {
            e.printStackTrace();

        }catch (SQLException e){
            e.printStackTrace();
        }finally {
            //释放资源
            if(rs!=null){
                try{
                    rs.close();

                }catch (SQLException e){
                    e.printStackTrace();
                }
            }


            if(conn!=null){
                try{
                    conn.close();

                }catch (SQLException e){
                    e.printStackTrace();
                }
            }

            if(stmt!=null){
                try{
                    stmt.close();

                }catch (SQLException e){
                    e.printStackTrace();
                }
            }

        }



        return list;


    }

}

输出结果如图：