Architecture-centric development addresses the increasing complexity and variability of software systems by focusing on architectural models, which are generally easier to understand and manipulate than source code. It requires a mechanism that can maintain architecture-implementation conformance during architectural development and evolution. The challenge is twofold. There is an abstraction gap between software architecture and implementation, and both may evolve. Existing approaches are deficient in support for both change mapping and product line architecture. This article presents a novel approach named 1.x-way mapping and its extension, 1.x-line mapping to support architecture-implementation mapping in single system development and in product line development, respectively. They specifically address mapping architecture changes to code, maintaining variability conformance between product line architecture and code, and tracing architectural implementation. We built software tools named xMapper and xLineMapper to realize the two approaches, and conducted case studies with two existing open-source systems to evaluate the approaches. The result shows that our approaches are applicable to the implementation of a real software system and are capable of maintaining architecture-implementation conformance during system evolution.

Existing software product line approaches often develop and evolve product line features, architecture, and source code independently, which makes it difficult to manage the relationship and conformance between these artifacts. This paper presents a novel approach using the architecture as a pivot to address this problem. It consists of a modeling mechanism that integrates features specification into an architectural model, and an architecture-implementation mapping mechanism that combines code generation with annotation processing. The approach can trace a product line feature to the architecture and source code, and automatically update the architecture and source code to maintain their conformance when feature changes occur. We implemented an Eclipse-based toolset to support the approach, and conducted a case study with the Apache Solr open-source system. The result shows that our approach is both applicable and capable to support the development and evolution of real-world variations of a software system.

It is essential to architecture-centric product line development that product line architecture can be used to drive activities specific to product line development, such as product derivation. This requires a mechanism that can automatically derive the architecture and code of a product instance from the customization of product line architecture. In this paper, we analyze the insufficiency of two existing solutions in this area and present an architecture-centric approach that meets the requirement. The approach can support product line differences in platforms and functions, and generate both product line code and product code. It is based on a product line implementation mechanism that combines a code generation and separation pattern with an architecture-based code annotation technique. We have implemented the approach, and finished a preliminary evaluation with a chat application.