java.lang.UnsupportedClassVersionError

I got an error like this trying to run a stand alone java class
Got fed up searching in the net.

Finally I found that I had more than 3 JREs installed in my machine, i tried removing all but one.

Even then it didnt work, due to bloody Oracle resetting the class path to its JRE version, which was an older one compared to what we were using.

So finally solved the problem by setting the class path to just one java library.