Research On Dynamic Updating Based-on Object-Oriented Software

With the wider application of software in everyday life, how to keep software continuous running without breaking while upgrading becomes an important topic in software maintain and software design. To software user, they may regard the ability to provide uninterrupted service as guide line.This paper makes research to theory and implementation about software updating, and proposes some methods for object-oriented software updating. We also do research on Internet ware dynamic updating. An evolving method was proposed for service evolving based on OSGi. The major innovative work in this dissertation is as follows.1. In order to resolve type-safety problem while updating O-O software dynamically, an update calculus was formulated as an extension of a core calculus for FJ (Featherweight Java). The calculus presents a restriction T-UPDATABEL to make sure type-safety while updating class. At last, we proof the result formally.2. During updating, object/method transferring is difficult to implement. MCUFJ is formulated through extending FJ to multi-version classes. The extension makes software dynamic updating wider and deeper. The paper also presents what kind of changes can be made in this situation and proves it.3. There are many limitations on updating classes in most of the previous works. In this paper, the update transaction was put forward to conquer these limitations. We also proved type-safety property formally. On the base of updating transaction, we propose a program degisn method for Java. At the end, an experiment was done for verify its feasibility. 4. Propose a method for resolving dynamic service evolving based on OSGi. First, use indirect method for updating service definition. The method can make dynamic evolving transparent. Then, divide service definition into implementation and data, which make fields in service instance consistent and evolvable.