目录结构：

 mysql：

此时的student表：

代码实现添加：

package demo1;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Scanner;

public class Test2 {
    public static void main(String args[]){
        Scanner in = new Scanner(System.in);
        Connection connection = null;
        Statement statement = null;

        System.out.println("请输入学号：");
        int num = in.nextInt();
        System.out.println("请输入姓名：");
        String name = in.next();
        System.out.println("请输入年龄：");
        int age = in.nextInt();

        try {
            //加载驱动
            Class.forName("com.mysql.jdbc.Driver");
            //建立连接
            //url的格式：主协议：自协议：名称
            String url = "jdbc:mysql://127.0.0.1/mysql_test?useUnicode=true&characterEncoding=utf8";
            connection = DriverManager.getConnection(url,"root","13474501003");
            //3.准备sql语句，Statement对象
            String sql = "INSERT INTO student(sno,sname,age)VALUES("+num+",'"+name+"',"+age+")";
            statement = connection.createStatement();

            //4.执行
            //适用于DML语句
            int n=statement.executeUpdate(sql);
            //5.处理结果
            if(n > 0){
                System.out.println("添加成功！");
            }else{
                System.out.println("添加失败！");
            }
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        }finally {
            try {
                if(statement != null) {
                    statement.close();
                }
                if (connection != null){
                    connection.close();
                }
            }catch (SQLException throwables) {
                throwables.printStackTrace();
            }
        }
    }
}

 执行成功：

在查询数据库student表添加成功：