Research On The Theory And Technology Of Web Services Architecture Based On REST

Nowadays, with the expediting process of economic globalization and the development of enterprise informatization construction, the inter-regional and inter-industry IT collaborations are becoming more and more popular, in this case, it is urgent to achieve the integration of heterogeneous information in distributed systems. For its standardization and high interoperability, Web services are emerging as a mainstream technology for heterogeneous data integration. As the architecture of Web services, SOA(Service-Oriented Architecture)are more and more often used for the construction of information sharing systems. But SOA is a typical RPC-styled architecture. In SOA, services are made up of several discrete procedures, and the interoperation among systems is achieved only by invoking remote procedures. This RPC-styled way will meet some problems such as the lack of scalability, low performance and high cost in Web-scale distributed applications. Aiming to solve these problems, the correlation theory and technology of Web services architecture are researched in this dissertation.The main work of this dissertation can be summarized as follows:1. On the basis of researches on architecture and architectural style, the inheritance relationship among Web services architecture, software architecture and architecture is revealed. The important role of architectural style in architecture design is clarified.The architectural properties of Web architecture are analyzed, which make Web can become an ultra-large-scale information sharing platform. Then REST is introduced as an architectural style which brings these properties to Web.2. Based on REST, RESTful services-oriented architecture(RSOA) is proposed. The design principles and architectural elements in RSOA are expounded. Following that, though a comparative analysis between RSOA and SOA, the advantages of RSOA is pointed out.3. For the same requirement, the implementations of RESTful Web Services and RPC-styled Web Services are both given. By comparison, the difference between two kinds of Web services is presented. Thus, building on the basis of two concepts: workflow and finite state automaton(FSA), the definition and formalized description of RESTful Web services workflow are provided. Combined an actual business process the state transition process is described.4. By comparing with other commonly used presentation formats, it is proved that RDFa is a suitable semantic annotation specification for RSOA. The semantic representations with RDFa are provided. The problems concerned service description and discovery are discussed. The approach to service description based on URI templates and the service discovery method based on Yadis protocol are proposed.The innovations in the dissertation can be listed as bellow:1. The successful factors of human web are introduced into programmable Web. A new Web services architecture based REST is proposed.2. The concept of RESTful Web services workflow is defined. The workflow follows the design principles of RSOA. It takes hypermedia as an engine of application state. At the same time, the formalized description of RESTful Web services workflow is given out.3. The semantics is added into RESTful Web service presentation by utilizing RDFa. RFDa semantic annotation can improve the self-description of RESTful Web services.4. The methods of service description and service discovery conforming to REST are worked out based on URI templates and Yadis protocol. They make technology system of RSOA more complete.From the application of the research result of this dissertation in common basic information platform for railway, it can be indicated that the system adopted RSOA has good scalability, low cost and has not platform dependency. So RSOA can meet the application requirement in large-scale distributed applications. In design principles, semantic representation and service description and discovery, the design of RSOA comply fully with REST. This way makes programmable Web and human Web achieve consistency on the architecture design level, which lays the foundation for the unity of two kinds of Web.