How to decompile java classes containing Synthetic classes?

Question

Java

Have a nice day everyone!
I want to understand the source code of some product written in Java6.
I have all the required .jar files for this application.
When decompiling them with the JD-GUI, some of the calls are decompiled as access$XXX. Although you can intuitively guess which method is being called, this is rather an exception to the rule.
When decompiling with Fernflower, those classes in which the JD-GUI displayed access$XXX do not contain anything at all (the file with the class name is empty).
Are there any automated methods for decompiling sythetic classes?
I would like to load all classes into the IDE (Eclipse or NetBeans) and be able to recompile individual classes (jar files).
PS. Perhaps I'm confused in terminology somewhere, I'm still new to this business =)
I would be grateful for any help!

Answer 1

Because when compiling sources into bytecode, information about the class is not completely saved.
Class names, methods, and class members are preserved, but local variables and method arguments are not. Such an access $XXX entry is similar to working with internal or nested classes, I assume the decompiler is unable to recover this information.