Software Architectural Refactoring Towards Architecture Pattern

Software inevitably undergoes continuous modifications to adapt to new changes which results in architectural decay and drift,and even software faults and failures.Architecture smell is a commonly used set of architectural design decisions that negatively impacts system quality such as understandability,testability,scalability and reusability.In this thesis,a pattern-oriented architecture refactoring method is proposed.According to different types of architecture smells requirements,appropriate architecture patterns are selected and applied to the current architecture to generate the refactoring scheme,eliminate the architecture smells and improve the quality of the software.To meet the architecture smell refactoring requirements of link overload,functionality overload and unnecessary dependency,we have apply five alternative architecture patterns,including layer pattern,plug-in pattern,whole and part pattern,orthogonal pattern and message-event pattern.The experimental results show that this method can apply appropriate architecture patterns into the architecture,eliminate the architecture smell and improve the quality of the software under the acceptable refactoring cost.And this method can be widely used in softwares.The main work of this thesis is as follows:(a)We conduct three architecture bad smells and propose a refactoring process for the removal of architecture smells;The concreate refactoring steps include architecture recovery,the generation of refactoring requirement,pattern respository,building decision tree(AP-RD-T),building,pattern selection,refactoring implementation and refactoring result evaluation.(b)For different types of architecture smells,we propose using architecture patterns as the elimination strategies for the architecture smells.(c)We formulate the architecture-layer refactoring scheme,which is organized by decision tree(AP-RD-T)and provide the specific mapping rules mapping the architecture-layer refactoring operations to the code-layer suggestions,so as to facilitate the analysis and implementation of the concreate refactoring.(d)Implement a pattern-oriented architecture refactoring tool.Architecture smell information as input,which is viewed as refactoring requirement,combined with user judgment,choose appropriate pattern to guide refactoring.Generate software architecture refactoring schemes in the form of decision tree(AP-RD-T).Execute pattern decision tree(AP-RD-T),generating architecture refactoring operations and a new architecture.And then generate corresponding code refactoring suggestions according to refactoring mapping rules,so as to facilitate the analysis and implementation of the concreate refactoring.(e)Through experiments,we verify that pattern-oriented architecture refactoring can eliminate the smells,at the same time,improve the software quality;We discuss that the cost of Pattern-Oriented architecture refactoring;At last,we verify that our method is extensive.