Properties(JDBC)连接mysql

properties 文件连接数据库

1. 创建db.properties文件

#数据库封装成外部文件
driver&＃61;com.mysql.cj.jdbc.Driver
url&＃61;jdbc:mysql://localhost:3306/j11?serverTimezone&＃61;Hongkong&useUnicode&＃61;true&characterEncoding&＃61;utf8&useSSL&＃61;false
#url&＃61;jdbc:mysql://localhost/j11?useSSL&＃61;false&CharacterEncoding&＃61;UTF-8&server&＃61;TUC
user&＃61;root
password&＃61;19990507


2.创建DButil

package com.xmx.util;import java.io.InputStream;
import java.sql.*;
import java.util.Properties;//封装数据库的连接
public class DButil {private static String drivername;private static String url;private static String username;private static String pwd;//静态代码块static {//1 读 db.propertiestry {InputStream is &＃61; DButil.class.getClassLoader().getResourceAsStream("com/xmx/util/db.properties");//2 属性集的类Properties p &＃61; new Properties();p.load(is);drivername &＃61; p.getProperty("driver");url &＃61; p.getProperty("url");username &＃61; p.getProperty("user");pwd &＃61; p.getProperty("password");} catch (Exception e) {e.printStackTrace();System.out.println("db.properties 参数出错.....");}}//连接public static Connection getConn() {try {//注册驱动Class.forName(drivername);//获取连接return DriverManager.getConnection(url, username, pwd);} catch (Exception throwables) {throwables.printStackTrace();}return null;}// 释放是资源public static void closeConn(Connection conn, PreparedStatement pst, ResultSet rs) {if (conn !&＃61; null) {try {conn.close();} catch (SQLException throwables) {throwables.printStackTrace();}}if (pst !&＃61; null) {try {pst.close();} catch (SQLException throwables) {throwables.printStackTrace();}}if (rs !&＃61; null) {try {rs.close();} catch (SQLException throwables) {throwables.printStackTrace();}}}}