Research On Polymorphism Of Java Programs Based On Program Slicing

Program slicing is an effective program analysis technique, which can extract the required part to analyze from the source program according to the given slicing criteria, such as program debugging, testing, reconstruction analysis of procedures and so on. Program slicing technique in structured programming has been more widely used, but like Java, the object-oriented language such procedures, in the aspect of application and research there are still some issues to be resolved. As a typical object-oriented programming language, the slicing technique of Java program is very representative. In Java program, such as process parameter, polymorphism, exception handling, multi-threaded problems and so on, is the focus and difficult problems in current field of the research of program slice technology.Through the analysis of process characteristics of Java language, especially the analysis of inter-dependence, the paper uses a improve system dependence graph (ISDG) to research polymorphism of Java programs. First make the local system dependence graph (LSDG) to every rewritten or covered method aiming at the reliance relations of method between the son and parent class, and then make system dependence graph (SDG) without the reliance relations on inter-object, and then target the relationship between the structure-dependent non-object inter-dependencies of system dependence graph (SDG). Finally, aiming at the reliance relations with inter-object in the ISDG of previous step add a dependency side between the methods rely on the side, and get the improved system dependence graph (ISDG). Using ISDG successfully solved problem of polymorphism expression in Java program. At the same time, this paper uses a Java program slicing criteria, and gives its slicing algorithm based on the ISDG.In order to make ISDG more universal and practical, ISDG will be extended to a more complex polymorphism problem in the papers. And aiming at the phenomenon that there is a large number of duplication of partial ISDG in the complicated ISDG, the papers proposed solution:The repeated node was marked as reusable leaves node. The solution simplified the ISDG, reduced complexity and increased efficiency. Through comparison with OODSDG using the method of instrumentation, the papers further demonstrates the features and advantages of ISDG.