Java Version for CREO Schematics 4.0 M010

I have complied custom JAVA code using JDK 1.8 (Version 52.0) that was supposed to work on Schematics 4.0 M010. I have gotten error code in the CMD window that opens when the schematics page that says

"Unsupported  major.minor version 52.0". From searches on the web it is explaining that my code is targeted

to run on JRE8 VM. I tried to cross compile my code to target JRE7 VM.Have been unsuccessful so far. Does anyone know the JAVA version that the current version of schematics is compatible with?