Java和MySQL的链接

不会Java和MySQL的链接，代码一点不会啊😭有人可以讲这个代码步骤是啥意思嘛

```package Util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class JDBCUtil {
    private static String driver = "com.mysql.cj.jdbc.Driver";
    private static String url = "jdbc:mysql://localhost:3306/restaurant";
    private static String userName = "root";
    private static String pwd = "b16959e2";
    
    public static Connection getConnection() throws ClassNotFoundException {
        Connection conn = null;
        try {
            conn = DriverManager.getConnection(url,userName,pwd);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
        
    }
    public static void close(ResultSet rs,PreparedStatement pstat, Connection conn) {
        try {
            rs.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        close(pstat,conn);
    }
    
    public static void close(PreparedStatement pstat, Connection conn) {
        try {
            pstat.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        try {
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        
    }
}

```

1、这是一个Java获取JDBC的util：JDBCUtil
2、分别定义了mysql的驱动、地址、账号、密码信息
3、getConnection() 获取一个jdbc链接
4、关闭连接。