Hadoop - Unsupported major.minor version 51.0

Question

I am new to hadoop and was trying to run the WordCount tutorial. I am getting the following error: Unsupported major.minor version 51.0 . I have seen some posts with the same error and I understand that the reason is that I am compiling my java with one JDK and running it with another. I already know I compile it with jdk 1.7 but how can I tell which version used to run it?

Thanks in advanced.

Answer 1

It must be some incompatibility with your jre version. Are you using jre 7 to run it?

On the other hand, you it's easier to compile a lower version from the source. Try this (for eg jdk 1.6):

javac -target 1.6 wordcount.java