After learning some java i was ready to start modding Minecraft so i downloaded everything i needed and everything was going perfect until... i went to command prompt to run gradlew.bat setupDecompWorkspace--refresh-dependencies where i got this error.

****************************

Powered By MCP:           

http://mcp.ocean-labs.de/ 

Searge, ProfMobius, Fesh0r,

R4wk, ZeuX, IngisKahn     

MCP Data version : unknown

****************************

Download http://files.minecraftforge.net/maven/net/minecraftforge/forge/1.7.2-10.12.0.1024/forge-1.7.2-10.12.0.1024-userdev.jar

 

FAILURE: Build failed with an exception.

 

* What went wrong:

The setupDecompWorkspace will only work with Java 7! This is fixed in ForgeGradle 1.2

 

* Try:

Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

 

I am currently using java8 and i understand the error came from there but do i really need to downgrade the java version? Or is there another way?

aup, you really need to downgrade. I did the same thing only to realise the same thing today. Because Java 8 is only just out, nothing has had time to update (like mods when a new version of Minecraft comes out). Make sure you have both JRE and JDK 7 and you set your path environment variable to point to it (there are a million guides of this, just search "JDK path environment variable" and repeat for JRE). Happy coding!

Thank you already downgrading