The Research Of Algorithm Visualization’s Representation And Implementation In Java Program Understanding

With the rapid development of software industry, the availability of legacy system (legacysystem) increased. These legacy software systems contain lots of useful information, includingrequirements analysis of the system, design patterns, business rules, system maintenance andrequirements changes used in the later period.But with the time growing, many documents anddesign information of the legacy system have been lost. This brings a lot of difficulties to thesoftware maintenance. If you can make the program understanding of the software fast,accurately, comprehensively is a key factor to judge your maintenance working successful.Therefore, the research on program understanding has a very important role for legacy softwaresystem’s development, maintenance and management.According to the requirements and the documents, the traditional software developmentprocess is to develop a program code. While the program understanding process is oppositive.First, we analyze program source codes, and then reconstruct the basic structure of software andalgorithm description documents. Last, we need perform them by graphics. These jobs can makeus to understand software system more conveniently. Based on the deep research studies of thedomestic and foreign references, this paper firstly discusses related research present situation, thebasic theory and technology of the program comprehension, Java virtual machine andvisualization technology. By studying of these basic theories, I design a program comprehensionsystem for Java, and make a research of the algorithm visualization.I draw these special images：class dependence graph、class hierarchy graph、function calling graph、control flow graph.Thepaper mainly includes the following aspects:.First of all is program information extraction. We need extract useful information. It is thebasic of program understanding and in order to display the program elements.Second, on the basis of the last working, we design the mapping relation–ship betweenJAVA language and UML according these two elements’s correspondence. And we save theclass, interface and function methods according to their categories. It is in order to displaydifferent components in different ways. The Third is the visualization of class dependency graph, class hierarchy graph, the methodcall graph and the method flow graph. We use the visualization technology to make acombination display of the elements from lexical analysis.