~~~ package JDBC.domain; /** * @author: hcf * @qq: 46914685 * @email: 46914685@qq.com */ import java.util.Date; /** * 封装Emp表数据的JavaBean */ public class Emp { private int id; private String ename; private int job_id; private int mgr; private Date joindate; private double salary; private double bounds; private int dept_id; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getEname() { return ename; } public void setEname(String ename) { this.ename = ename; } public int getJob_id() { return job_id; } public void setJob_id(int job_id) { this.job_id = job_id; } public int getMgr() { return mgr; } public void setMgr(int mgr) { this.mgr = mgr; } public Date getJoindate() { return joindate; } public void setJoindate(Date joindate) { this.joindate = joindate; } public double getSalary() { return salary; } public void setSalary(double salary) { this.salary = salary; } public double getBounds() { return bounds; } public void setBounds(double bounds) { this.bounds = bounds; } public int getDept_id() { return dept_id; } public void setDept_id(int dept_id) { this.dept_id = dept_id; } @Override public String toString() { return "Emp{" + "id=" + id + ", ename='" + ename + '\'' + ", job_id=" + job_id + ", mgr=" + mgr + ", joindate=" + joindate + ", salary=" + salary + ", bounds=" + bounds + ", dept_id=" + dept_id + '}'; } } ~~~ ~~~ package JDBC; /** * @author: hcf * @qq: 46914685 * @email: 46914685@qq.com */ import JDBC.domain.Emp; import java.sql.*; import java.util.ArrayList; import java.util.List; /** * 定义一个方法,查询emp表的数据将其封装为对象,然后装载集合,返回. */ public class JDBCDemo8 { public static void main(String[] args) { List<Emp> list = new JDBCDemo8().findAll(); System.out.println(list); System.out.println(list.size()); } /** * 查询所有emp对象 * * @return */ public List<Emp> findAll() { Connection conn = null; Statement stmt = null; ResultSet rs = null; List<Emp> list = null; try { //1.注册驱动 Class.forName("com.mysql.cj.jdbc.Driver"); //2.获取连接 conn = DriverManager.getConnection("jdbc:mysql:///db1?serverTimezone=UTC", "root", "admin123"); //3.定义sql String sql = "select * from emp"; //4.获取执行sql的对象 stmt = conn.createStatement(); //5.执行sql rs = stmt.executeQuery(sql); //6.遍历结果集,封装对象,装载集合 Emp emp = null; list = new ArrayList<Emp>(); while (rs.next()) { //判断是否有数据 int id = rs.getInt("id"); String ename = rs.getString("ename"); int job_id = rs.getInt("job_id"); int mgr = rs.getInt("mgr"); Date joindate = rs.getDate("joindate"); double salary = rs.getDouble("salary"); double bouns = rs.getDouble("bouns"); int dept_id = rs.getInt("dept_id"); //创建emp对象 emp = new Emp(); emp.setId(id); emp.setEname(ename); emp.setJob_id(job_id); emp.setMgr(mgr); emp.setJoindate(joindate); emp.setSalary(salary); emp.setBounds(bouns); emp.setDept_id(dept_id); //装载集合 list.add(emp); } } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException throwables) { throwables.printStackTrace(); } finally { //7.释放资源 if (rs != null) { try { rs.close(); } catch (SQLException throwables) { throwables.printStackTrace(); } } if (stmt != null) { try { stmt.close(); } catch (SQLException throwables) { throwables.printStackTrace(); } } if (conn != null) { try { conn.close(); } catch (SQLException throwables) { throwables.printStackTrace(); } } } return list; } } ~~~