Research of Abstract Class and Interface of Java

Two mechanisms of abstract class and interface are supported for the abstract class definition of Java language.Being of two mechanisms endow the powerful ability of OO.There have great similarities that two mechanisms of abstractclass and interface are support for the abstractclass definition,therefore,the choice is random.But the distinction of the two is great.The distinction was made from the two definitions,procedures editorial,design intentation in this article.So,it is the key that how to choose them to make the designed-intention right and reasonable when the system is designed.