【1030练习】JDBC查询表格并展示

Emp.java

package cn.itcast.domain;

import java.util.Date;


public class Emp {
    private int id;
    private String ename;
    private int job_id;
    private int mgr;
    private Date joindate;
    private double salary;
    private double bonus;
    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 getBonus() {
        return bonus;
    }

    public void setBonus(double bonus) {
        this.bonus = bonus;
    }

    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 +
                ", bonus=" + bonus +
                ", dept_id=" + dept_id +
                '}';
    }
}

jdbcdemo.java

import cn.itcast.domain.Emp;

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



public class jdbcdemo {

    public static void main(String[] args) {
        List list = new jdbcdemo().findAll();
        System.out.println(list);
    }
    

    public List findAll(){ //方法返回一个List集合，集合里面为Emp对象
        Connection conn =null;
        Statement stmt = null;
        ResultSet rs = null;
        List list = null;
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql:///db3", "root", "admin");
            String sql = "select * from emp";
            stmt = conn.createStatement();
            rs = stmt.executeQuery(sql);
            Emp emp = null;
            list = new ArrayList();
            while(rs.next()){
                int id = rs.getInt(1);
                String ename = rs.getString(2);
                int job_id = rs.getInt(3);
                int mgr = rs.getInt(4);
                Date joindate = rs.getDate(5);
                double salary = rs.getDouble(6);
                double bonus = rs.getDouble(7);
                int dept_id = rs.getInt(8);
                //创建对象，并赋值
                emp = new Emp();
                emp.setId(id);
                emp.setEname(ename);
                emp.setJob_id(job_id);
                emp.setMgr(mgr);
                emp.setJoindate(joindate);
                emp.setSalary(salary);
                emp.setBonus(bonus);
                emp.setDept_id(dept_id);

                //装载集合
                list.add(emp);
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }finally {
            if(conn!=null){
                try {
                    conn.close();
                } catch (SQLException throwables) {
                    throwables.printStackTrace();
                }
            }
            if(stmt!=null){
                try {
                    stmt.close();
                } catch (SQLException throwables) {
                    throwables.printStackTrace();
                }

            }
            if(rs!=null){
                try {
                    rs.close();
                } catch (SQLException throwables) {
                    throwables.printStackTrace();
                }
            }
        }
        return list;
    }
}

运行结果：