Java Interface Overview
Interface: Interfaces can be used to implement the Inheritance relationship between the non-related classes that do not belongs to the same hierarchy, i.e. any Class and any where in hierarchy. Using Interface, you can specify what a class must do but not how it does.
- A class can implement more than one Interface.
- An Interface can extend one or more interfaces, by using the keyword extends.
- All the data members in the interface are public, static and Final by default.
- An Interface method can have only Public, default and Abstract modifiers.
- An Interface is loaded in memory only when it is needed for the first time.
- A Class, which implements an Interface, needs to provide the implementation of all the methods in that Interface.
- If the Implementation for all the methods declared in the Interface are not provided , the class itself has to declare abstract, other wise the Class will not compile.
- If a class Implements two interface and both the Intfs have identical method declaration, it is totally valid.
- If a class implements tow interfaces both have identical method name and argument list, but different return types, the code will not compile.
- An Interface can't be instantiated. Intf Are designed to support dynamic method resolution at run time.
- An interface can not be native, static, synchronize, final, protected or private.
- The Interface fields can't be Private or Protected.
- A Transient variables and Volatile variables can not be members ofInterface.
- The extends keyword should not used after the Implements keyword, the Extends must always come before the Implements keyword.
- A top level Interface can not be declared as static or final.
- If an Interface species an exception list for a method, then theclass implementing the interface need not declare the method withthe exception list.
- If an Interface can't specify an exception list for a method, the class can't throw an exception.
- If an Interface does not specify the exception list for a method, he class can not throw any exception list.
- Further information can be found at:
http://www.abapprogramming.net
AP - President-elect Barack Obama and his wife, Michelle, said their young daughters will still have to do chores in the White House and won't get out of doing homework just because they're the president's children. In an interview with Barbara Walters, the Obamas said Sasha, 7, and Malia, 10, will have lives as normal as possible. That means helping out around the house.
