【正文】 ith the realization of the way, produce professional Demo can have only static cannot be modified data members, all the members of the methods is abstract. In a sense, with a special kind of abstract class. From programming, from the perspective of abstract scaleup and with can be used to achieve cancel thoughts make themselves. But in the specific use top still have some difference. First, abstract class in Java language suggests is a kind of inheriting relationship, a class can be used only once inheritance relationship (because Java do not support more inheritance ZhuanZhu). However, a class but can implement multiple with. Maybe it is Java language designers in considering Java for multiple inheritance support of a promise to consider it. Secondly, in the definition of abstract scaleup, we may give methods of default behavior. But in with the definition of method cannot have the default behavior, to bypass this limits, must use entrust, but it will add some plexity, sometimes can cause a lot of trouble. In class abstraction cannot define the default behavior is there another serious problem that may cause on the maintenance of trouble. Because if later want to modify the interface (usually by such abstract scaleup or with to represent) to adapt to the new situation (., adding new methods or to have already used the method to add new parameters), will be very troublesome, might spend a lot of time (for a derived class many situation, especially). But if the interface is through scaleup abstract to realize, then may just need to modify defined in the abstract scaleup default behavior is ok. Similarly, if not in abstract class defined in the default behavior, can lead to the same method to appear in the abstract class every a derived class, violated aone rule, principle, causing aone place, the same code duplication against future maintenance. Therefore, in the abstract scaleup and with a choice between should be careful. From the design concept with abstract class and interface It mainly from grammar definition and programming perspective, this paper discusses the area with abstract class and don39。t, these levels difference is relatively low levels of, the essence. This section will from another level: abstract class and with reflected design concept, analyst the difference. The author thinks that from this level analysis to understand the essence of both concepts. As already mentioned, abstract class in Java language reveals a kind of inheriting relationship, want to make reasonable, the inheritance relationship between parent class and derived class must exist is a relations, namely the super class and derived class in concept in essence should be the same. For with criterion otherwise, it does not require with of implementers and with defined in concept is essentially a consistent, only is realized with defined a contract is just. In order to facilitate understandings. Consider such a example, suppose in our problem field has a about filled the abstract concepts, this filled with executive two movements open and close, then we can through scaleup or abstract with to define a said the abstract concept of type, define each pattern . Other concrete filled type can use extends the abstract class defined or filled with defined using implements the filled. Look like using abstract class and with no much difference. If