Research On Dynamic Updating Based On Classes And Objects Of Object-oriented Software

Both hardware and software for computers have been greatly improved since the fifties of the twentieth centhry. Application software’s scale has increased quickly and the architecture of application has been more and more complicated.Many applications have been a key role in some industries. Unfortunately, more and more defects and bugs were introduced into the software while the scale was increasing. We must be faced with such a situation that’The Perfect Software’ has never existed although software engineering has done its best to avoid that.Since every application may have defects and bugs more or less,a lot updating patches have been developed to eliminate defects, to fix bugs,or to improve the functions.This is called software updating.Every modern organization has software systems are critical to its mission and must operate continuously. Many applications also need to keep running continuously for24/7(24hours per day and7days per week) to improve quality of services. Such requirements are common in important sectors of the impact on the livelihood of national planning. These services may be provided by the software maintains a large number of data, it would bring the alarming loss if these services has been interrupted. A network provider, for example, loses both revenue and customer goodwill if its swithes or service controllers are temporarily unavailable. Dynamic update is a new software evolution technology, updates to the software modules aimed at stopping the machine conditions, it has become research hotspots.This article is based on object-oriented technology, software service does not stop when the calss update happened. The profile is divided into class already exists and the class does not exist in the system. Divided into four cases according to the difference between the new class and old class. Same Type, SuperType, SubType, and Unrelated Type, in which the SameType is differ from language, some languages do not support one type of two classes defined at the same time;SuperType is rarely, these four divided into the match type and unmatch type. Detailed analysis of the class dynamic update mechanism, this paper, the the centralized dynamic update mechanism, improve the separation of interface and implementation class update method developed an agent-based access to the class to achieve indirectly accessed through a proxy. We also researched the dependencies among objects during updated. A class of updates sometimes cause many classes of updates,I used a directed graph to slove this problem.I build a Java-based dynamic updates. The experiments show that the update overhead, experiment proves the correctness of updated.