I have read in one book,that is Is empty source file a valid java source file?The answer they gave is yes.I could not get the right explanation. i don'y know what they mean.withot interface,class,package,import how can a file will be a valid source file? Its confusing me.
If you browse to JLS 7.3: Compilation Units, you will see that a compilation unit (i.e., a Java source file) is composed of three high level elements, called PackageDeclaration, ImportDeclarations, and TypeDeclarations. All of them are optional, which clearly means that an empty compulation unit is a valid java file. I hope this clears your doubts.