The Design And Implementation Of Android Based Nfc Service Framework

Currently, Near Field Communication technology is developing fast in the world wide. This technology is not only the enablers for ubiquitous computing but also provides secure communication between two computing devices. Google has integrated NFC into Android system, which has created an environment for developers to build different kinds of NFC applications. But for developers, when developing NFC applications, they have to own some indispensable knowledge of NFC technology or related protocols. For example, they shall know the NDEF data format to parse the actual data from NFC Forum tags. Moreover, Android provides no APIs to ensure integrity and confidentiality for data in NFC tags and all those works have to be done by developers themselves. And even worse, most of above works are repeated and trivial. In order to solve those problems, this paper proposes a framework, NFC Service Framework, to reuse the repeated works. Based on the framework, developers are able to build NFC applications rapidly and efficiently. The research of this paper can be summarized as follows:1) This paper gives an overview of basic NFC knowledge, three kinds of NFC operation mode and related typical use cases. Then this paper offers an introduction for developing NFC applications on Android platform.2) To solve problems described above in NFC application development, this paper proposes a layered framework based on Android for creating NFC services composed to NFC applications. The framework can be divided into two layers, the under layer, Data Access Layer, is responsible for handling NFC related content such as parsing NFC tag data. And the upper layer, Service Framework Layer, abstracts the business logic and UI form NFC applications. In other words, NFC related content will be transparent to NFC service developers. As a result, developer can build NFC applications rapidly since the reuse work in NFC Service Framework.3) This paper describes a design for Data Access Layer, the main content of which is about the use of design patterns and related developing technologies. For example, Data Access Layer is capable of parsing different NFC technology tags by applying decorator design pattern. And the integration of composite design pattern and XML makes parsing processes of NFC data configurable, extendable and reusable.4) On the design of Service Framework Layer, by offering lifecycle callback methods, this layer hides the NFC related content. Moreover the use of factory method design pattern and Java reflection realizes the automatic NFC data retrieval.5) Finally, this paper gives an introduction for developing methods based on NFC Service Framework, which includes the building of development environment, the role assignment of development team members and the test for NFC Service Framework with two application projects.