If this class is only a utility class, you should make the class final and define a private constructor:

public final class FilePathHelper {

   private FilePathHelper() {
      //not called
   }
}

This prevents the default parameter-less constructor from being used elsewhere in your code. Additionally, you can make the class final, so that it can't be extended in subclasses, which is a best practice for utility classes. Since you declared only a private constructor, other classes wouldn't be able to extend it anyway, but it is still a best practice to mark the class as final.