1. Introduction Problem Statement Research Goals Conclusion Contact / More Information { shimin, ltahvild }@swen.uwaterloo.ca Componentizing legacy system is essential for the maintenance and the reuse. However, the major problem against the widespread introduction of componentization is the lack of cost-effectively identifying and extracting reusable components from legacy systems. Research Focus Java Legacy System Componentization Figure 1 – Overview of Java Legacy System Componentization Target System Class … … Java Legacy System Class … … … … … Class or Interface Reusable Component Dependency Java Legacy system (S) = { C, I, R CI, F, F AI } Java Legacy system (S) = { C, I, R CI, F, F AI }  C – the set of all classes of the legacy system.  I – the set of all interfaces of the legacy system.  R CI – the static structure relationship set among classes and interfaces. It is modeled as a Class and Interface Dependency Graph (CIDG).  F – the set of functional features provided by the system.  F AI – the set of abstract implementation of features. It is modeled as a Feature Abstract Implementation Model (FAIM).  Proposed a framework for extracting reusable components from a Java legacy system and migrating from the legacy system to a component-based system in a cost-effectively manner by analyzing the static system structure and identifying and encapsulating the functional features.  Developed an integrated componentization environment to perform information retrieving, system modeling, component extracting, and system migrating. Integrated Componentization Environment Legacy Systems (.java files) Parser System Models (XML Doc) Modeler Decomposer Decomposition Rule (XML Doc) Raw Data (XML Doc) Meta-models (XML Schema) CIDG meta-model FAIM meta-model CIDG, FAIM Decomposition Algorithm Reusable Components Component-Based System  An Eclipse Rich Client Platform (RCP) application  Provide three perspectives:   Parser  Modeler   Decomposer  Easily extensible to other perspectives such as:  Evaluation  Integration Java Legacy System Model Componentization Algorithm Class and Interface Dependency Graph (CIDG) Feature Abstract Implementation Model (FAIM) Class Class or Interface DI (Dependency Indicator) = (IH, RZ, AS, AG, CO, US) If Inheritance relationship presents, IH = 1; otherwise IH = 0 If Realization relationship presents, RZ = 1; otherwise RZ = 0 If Association relationship presents, AS = 1; otherwise AS = 0 If Aggregation relationship presents, AG = 1; otherwise AG = 0 If Composition relationship presents, CO = 1; otherwise CO = 0 If Usage relationship presents, US = 1; otherwise US = 0 Class … DI Class … M1M1 N D H Class … M2M2 N D H Class … MnMn N D H … FAIM = { M 1, M 2, …, M n } M i = { N, D, H }, 1 ≤ i ≤ n N – name of the feature D – description of the feature H – host class/interface set of the feature  Input  A  A Java legacy system  The  The Class and Interface Dependency Graph (CIDG)  The Feature Abstract Implementation Model (FAIM)  Output   Target system (Component-based system)   It is a set of classes, interfaces, and reusable components.   Each component in the set does not have any dependency upon the artifacts which are outside of the component. Hence the component can be reused individually.   A list of reusable components  Each component provides a well-defined interface as the entry into the component from outside.   Each component can be packaged into a Java Archive (JAR) file. Abstract  Design and develop a methodology for migrating from a Java legacy system into a component-based system and extracting all reusable components from the system by  retrieving static structure of the legacy system  extracting functional features that are scattered across multiple methods and classes classes  encapsulating the extracted features to change into reusable components  Minimize the componentization cost by  retrieving automatically the system static structure  identifying and encapsulating the feature as automatically as possible  performing the reengineering process with a low level of source code modification which may be done automatically  Design a modeling paradigm to identify static structures of a legacy system.  Design a modeling paradigm to identify the features of a legacy systems based on some user requirements.  Develop a componentization algorithm to migrate from a legacy system to a component-based system and extract all reusable components using the above modeling paradigms.  Design and develop an integrated componentization environment to perform information retrieval, system modeling, component extracting, and system migrating. Evolving over a number of years, object-oriented legacy systems embody substantial corporate knowledge, including requirements, design decisions, and business rules. In order to reuse these assets in a cost-effective manner, it is important to develop a systematic strategy for reengineering the object-oriented legacy system. This research proposes a framework for extracting reusable components from a Java legacy system and migrating them to a component-based system by encapsulating reusable features. Such features may be used as reusable components in a cost-effective way. An integrated experimental environment for performing the extraction and migration processes has been designed and developed as an Eclipse RCP application. Figure 2 – Overview of Integrated Componentization Environment Figure 3 – A Screenshot of the Integrated Componentization Environment Decomposing Java Legacy Systems into Components Shimin Li and Ladan Tahvildari