报错内容：
Error: A JNI error has occurred, please check your installation and try again
Exception in thread “main” java.lang.UnsupportedClassVersionError: Demo has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
解决方法：
系统中以前安装了一次JRE8u164，在没有卸载的前提下又安装了JDK11.0.2，估计是产生了冲突，删除JRE8u164即可。
扩展内容
有关JDK,JRE,JAVA SE,JAVA EE,JAVA ME的概念和区别见：
https://www.cnblogs.com/In-order-to-tomorrow/p/3652315.html
