It is possible to convert class files in to java files,but however it is impossible to achieve the originally written format.
For example by using a java editor,we can give variable names whatever we want but after it is compiled (turned into class file) the variable names are optimized.That is only one example, also they are various optimizations are performed during compilation.So when we turn the class file into java file again we lose that infos.Also we lose the comments we write.
You can find java decompilers in the internet easily for free.
Salih Sipahi
Software Engineer.
City of Istanbul Turkey
s.sipahi@sahinlerholding.com.tr