Exception in thread “main“ java.lang.UnsupportedClassVersionError: MapReduce/WordCount has been comp

实验过程中在运行“./bin/hdfs dfs -cat output/*”语句查看结果时发生以下报错：

Exception in thread "main" java.lang.UnsupportedClassVersionError: MapReduce/WordCount has been compiled by a more recent version of the Java Runtime (class file version 60.0), this version of the Java Runtime only recognizes class file versions up to 52.0

上网查找后发现是由较高版本的JDK编译的java class文件试图在较低版本的JVM上运行产生的错误

解决办法为

首先在终端窗口中用java -version命令查看安装的java的版本

然后在对应项目上右键->properties->java compiler->compiler compliance level处选择对应的版本

之后即可。