Java J2ee Planet

It is possible create an abstract class with all concrete methods. But this class can’t be instantiated. Since it is an abstract class.    We may have situations where we don’t want to instantiate a class which is the base class for all the classes in the system or application. This base class may have lot of methods used for different modules in the application and we do not want to instantiate the object of the base class and want to use only the reference of the class.   An abstract class without any abstract methods should be a rare thing and you should always question your application design if this case arises. Normally you should refactor to use a concrete super class in this scenario.   One specific case where abstract class may justifiably have no abstract methods is where it partially implements an interface, with the intention that its subclasses must complete the interface.