Overriding rules in Java

• Should be same method name and argument list in base class and derived class
• Return type can be co-variant, meaning if super class return type is Map, subclass return type can be Hash Map.
• Access specifier in the derived class should be broader/bigger than that in the base class;
• ie; if base class method is protected, the derived class method can  be protected or public- but cannot be private or default
• Exception in the subclass  should be same or subclass of base class
• ie:-if base class exception is IOException, subclass can be FilenotFoundException-but cannot be Exception.