package com.system.utils;

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

public class DB {

	// 数据库地址
	private String Driver_name = "jdbc:mysql://localhost:3306/student_a?serverTimezone=Asia/Shanghai&useSSL=false";
	// 数据库用户名
	private String USER = "root"; // 这里需要修改为自己的用户名和密码
	// 数据库密码
	private String PASS = "Wyy031105";
	// 数据库连接
	public static Connection con;

	// 构造方法
	public DB() {
		try {
			// 加载驱动
			Class.forName("com.mysql.cj.jdbc.Driver"); // 这个驱动是mysql8版本的
			// 获取连接
			con = DriverManager.getConnection(Driver_name, USER, PASS);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	// 获取连接
	public static Connection getConnection() {
		if (con == null) {
			new DB();
		}
		return con;
	}

	// 释放连接
	public static void close(ResultSet resultSet, Statement statement, Connection connection) {

		if (resultSet != null) {
			try {
				resultSet.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}

		if (statement != null) {
			try {
				statement.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}

		if (connection != null) {
			try {
				connection.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}

	// 释放连接
	public static void close(Statement statement, Connection connection) {

		if (statement != null) {
			try {
				statement.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}

		if (connection != null) {
			try {
				connection.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}

	// 释放连接
	public static void close(Connection connection) {

		if (connection != null) {
			try {
				connection.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}

}