关于java中连接centos7上的mysql

windows里mysql能连接并操作阿里云centos7 上的mysql。但java中不能连接。

private static String driver="com.mysql.cj.jdbc.Driver";

private static String url="jdbc:mysql://XX.XX.XX.XX:3306/plane?useUnicode=true&characterEncoding=utf-8&useSSL=false";//&serverTimezone = GMT

private static String user="root";

private static String password="GCw990618!";

报错信息： com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.