mysql数据库的连接库代码

driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://localhost:3306/studentuseUnicode=true&characterEncoding=utf8&useSSL=true
username=suzili
password=123456

package com.su.less01.Utils;
import java.io.InputStream;
import java.sql.*;
import java.util.Properties;

public class JdbcUtils {
    private static String driver=null;
    private static String url=null;
    private static String username=null;
    private static String password=null;
   static {
       try{
           InputStream in = JdbcUtils.class.getClassLoader().getResourceAsStream("db.properties");
           Properties properties=new Properties();
           properties.load(in);

           driver = properties.getProperty("driver");
           url = properties.getProperty("url");
           username = properties.getProperty("username");
           password = properties.getProperty("password");
           //1、驱动只用加载一次
           Class.forName(driver);
       } catch (Exception e) {
           e.printStackTrace();
       }
   }
   //获取连接
public static Connection getConnection() throws SQLException {
    return DriverManager.getConnection(url,username,password);
}
//释放资源
    public static void release(Connection conn, Statement st, ResultSet rs){
       if(rs!=null){
           try {
               rs.close();
           } catch (SQLException e) {
               e.printStackTrace();
           }
       }
       if(st!=null){
           try {
              st.close();
           } catch (SQLException e) {
               e.printStackTrace();
           }
       }
       if(conn!=null){
           try {
              conn.close();
           } catch (SQLException e) {
               e.printStackTrace();
           }
       }



    }
}