Research And Implementation Of A Context-Oriented Context-awareness Programming Framework

With emergence of the Internet and the quick development of mobile information technology, the execution environment of the software has been changed from closed static to open and dynamic. It is obvious that environment context has more and more impact on the applications, especially in mobile computing field. With the growing popularity of mobile computing devices, a large number of applications that are related to environmental factors have emerged, such as location-based applications. Mobile devices have obvious advantages in terms of mobility, portability, real-time communication. With the enhancement of processing power and the increase of sensor applications, the mobile devices can collect contextual information in anytime and anywhere. Contextual information is used in mobile devices such as smart cellphone, PDA and tablet computer, but there’re still a lot of problems in developing context-aware applications. Traditionally there’s no explicit expression of context. The contextual information and context-related functions are often scattered by using branch statements and tightly coupled to application’s business logic. By the traditional modeling and programming way, context-aware applications are difficult to react to the open and dynamic contexts when more and more environmental factors appear and their complex relationship change. Therefore, a new paradigm of context-awareness programming comes up by treating context as an explicit programming element. The program can dynamically access to contextual information around at run-time, and make a reasonable reaction based on such dynamically changing context information. The main contributions of this paper include:1) We compare the popular definitions of context as well as their solutions and prototype implementation, and summarize the common modules and design patterns required by the context-aware application development.2) A novel context-aware application programming framework was proposed based on the above patterns. It can support context definition, fusion and publication. And application behaviors can be driven and constrained by adaptation rules in a context-aware manner. With this framework, legacy applications can be easily extended and their context-awareness can be enhanced in a non-intrusive way. In this framework a solution is also proposed to solve the collision of the application’s adaptation rules.3) We implement the proposed context-awareness programming framework based on Java. And the execution platform is also implemented for context-aware applications running on PC and Android platform.An indoor intelligent application is developed to show the feasibility, practicality and portability of the programming framework. Moreover, an Eclipse plug-in for the proposed framework is implemented to facilitate context and context-aware rules development.