I think java “abstract” keyword evolved from c++ pure virtual…
abstract AND synchronized @@ no idea. I think [[ java precisely ]] covers this.
abstract AND private @@ No. http://java.sun.com/docs/books/jls/second_edition/html/classes.doc.html#11244
abstract AND final @@ no. can’t be implemented
— abstract AND static @@ —
No. “It is a compile-time error for a static method to be declared abstract.” http://java.sun.com/docs/books/jls/second_edition/html/classes.doc.html#11246 It all boils down to runtime^compile-time binding. First, you need to really understand that static calls are resolved at compile time — based on the declared type.
In general, given any static method s() in any baseclass B redefined in any subclass C, then C.s() can never step in to help B.s(). This holds whether B.s() is abstract or concrete.
Therefore, an abstract static method is an unfillable dental /cavity/, an /unrecoverable liability/. Such a construct makes no sense.