Error(1,1)illegalcharacter '\ufeff' when compiling on android studio

Question

I got an Eclipse project source code(I was told that on Android Studio, maybe they just confused), and I start to migrating the code to android studio refers to

Answer 1

Above are great solutions. However, if none of them works, try this one:

Open the file in Notepad++; Copy everything; Create a new file with the same name; Paste everything; Save it.

Now it is gone.