Static final public synchronized abstract

1.static final public synchronized can be mixed and unlimited in order

2.abstract can only be used with public or protected, cannot use default or private nor with any of the static final synchronized

Reason:

Abstract to inherit (polymorphic)

But the static is the compile-time binding, which rejects polymorphic

Synchronized no inheritance, the parent class lock subclass is not locked by default, so adding Synchtonizd is useless

Final itself is to prevent rewriting

Static final public synchronized abstract