Exception in thread main java lang UnsupportedClassVersionError

Question

Getting the below error while running hadoop map reduce job.

Exception in thread "main" java.lang.UnsupportedClassVersionError: com/kamran/mapreduce/WordCountDemo has been compiled by a more recent ve
rsion of the Java Runtime (class file version 54.0), this version of the Java Runtime only recognizes class file versions up to 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at org.apache.hadoop.util.RunJar.run(RunJar.java:214)
at org.apache.hadoop.util.RunJar.main(RunJar.java:136)

Answer 1

Try removing the / before the input path location in the command that you are giving for the map reduce code:

hadoop jar UnderstandingMapReduce.jar com.kamran.mapreduce.WordCountDemo WordCountDemo/Input/WordCou ntDemoInput.txt WordCountDemo/Output/WordCountDemoOutput

Answer 2

Hi,

keep in mind do not forget to change the java home path in the conf file.