stuDAO

package com.xiaohu.dao;

import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

import com.xiaohu.entity.StuEntity;

import java.sql.Connection;

public class stuDAO {
    static Connection conn = null;
//    链接数据库
    public static void dbConnect() {
        String driver = "com.mysql.cj.jdbc.Driver";
        
        String url = "jdbc:mysql://localhost:3306/test";
        String user = "root";
        String password = "123456";
        
        try {
            Class.forName(driver);
            conn = DriverManager.getConnection(url,user,password);

        } catch (Exception e) {
            e.printStackTrace();
        }
        
//        if(conn == null) {
//            System.out.println("连接数据库失败！");
//        }else {
//            System.out.println("连接数据库成功！");
//
//        }
        
    }
//    添加学生信息
    public void add() {
        dbConnect();
        Scanner sa = new Scanner(System.in);
        System.out.println("请输学号");
        int sid = sa.nextInt();
        System.out.println("请输入姓名");
        String sname = sa.next();
        System.out.println("请输入性别");
        String ssex = sa.next();
        System.out.println("请输入年龄");
        int sage = sa.nextInt();
        System.out.println("请输入地址");
        String saddress = sa.next();
        sa.close();
        
        StuEntity stu = new StuEntity();
        stu.setSid(sid);
        stu.setSname(sname);
        stu.setSsex(ssex);
        stu.setSage(sage);
        stu.setSaddress(saddress);
        
        try {
            String sql = "insert into stuinfo values(?,?,?,?,?)";
            PreparedStatement pre;
            pre = conn.prepareStatement(sql);
            
            pre.setInt(1,stu.getSid());
            pre.setString(2, stu.getSname());
            pre.setString(3,stu.getSsex());
            pre.setInt(4, stu.getSage());
            pre.setString(5, stu.getSaddress());
            
//            提交
            pre.executeUpdate();
        } catch (Exception e) {
            e.printStackTrace();
        }
    
        
    }
//    全查询
    public List<StuEntity> getAll() {
        dbConnect();
        List<StuEntity> ar = new ArrayList<StuEntity>();
        try {
            String sql = "select * from stuinfo";
            PreparedStatement pre = conn.prepareStatement(sql);
            ResultSet rs = pre.executeQuery();
            
            while(rs.next()) {
                int sid = rs.getInt("sid");
                String sname = rs.getString("sname");
                String ssex = rs.getString("ssex");
                int sage = rs.getInt("sage");
                String saddress = rs.getString("saddress");
                
                StuEntity stu = new StuEntity();
                stu.setSid(sid);
                stu.setSname(sname);
                stu.setSsex(ssex);
                stu.setSage(sage);
                stu.setSaddress(saddress);
                ar.add(stu);
            }
            
            
        }catch(Exception e) {
            
        }
        return ar;
    }
}

StuEntity

package com.xiaohu.entity;

public class StuEntity {
    private int sid;
    private String sname;
    private String ssex;
    private int sage; 
    private String saddress;
    
    public int getSid() {
        return sid;
    }
    public void setSid(int sid) {
        this.sid = sid;
    }
    public String getSname() {
        return sname;
    }
    public void setSname(String sname) {
        this.sname = sname;
    }
    public String getSsex() {
        return ssex;
    }
    public void setSsex(String ssex) {
        this.ssex = ssex;
    }
    public int getSage() {
        return sage;
    }
    public void setSage(int sage) {
        this.sage = sage;
    }
    public String getSaddress() {
        return saddress;
    }
    public void setSaddress(String saddress) {
        this.saddress = saddress;
    }
    
}

Test1

package com.xiaohu.test;

import com.xiaohu.dao.stuDAO;

public class Test1 {
    public static void main(String[] args) {
        stuDAO stu = new stuDAO();
        stu.add();
    }
}

Test2

package com.xiaohu.test;

import java.util.List;

import com.xiaohu.dao.stuDAO;
import com.xiaohu.entity.StuEntity;

public class Test2 {
    public static void main(String[] args) {
        System.out.println("学号\t姓名\t性别\t年龄\t地址");
        stuDAO stu = new stuDAO();
        List<StuEntity> ar = stu.getAll();
        for(int i=0;i<ar.size();i++) {
            System.out.println(ar.get(i).getSid()+"\t"+ar.get(i).getSname()+"\t"+ar.get(i).getSsex()+"\t"+ar.get(i).getSage()+"\t"+ar.get(i).getSaddress());
        }
    }
}