Unable to find class 'List' ] Cannot make a static reference to the non-static method getFileOld() from the type FileData Cannot make a static reference to the non-static method getFileNew() from the type FileData
From above statements in your question , it seems you are accessing nonstatic methods by FileData (I think its a class).If methods are nonstatic then you cant access your methods lisk this
Classname.nonstatic_method (not-allowed)
Classname.static_method (allowed)
Try your code by making your both methods static. OR make object of FileData and then access nonstatic methods