Web Services Stack Research Articles

A Java Based Web Service Model for Library Information Discovery

Library information discovery is a vital aspect of education development and management. Nowadays, many libraries offer the information regarding to facilities, resources and services to users through their website. The existing library information systems discover only their information and do not integrate the related information from other libraries. Therefore, web service technology has been developed, which is uses a standard interface to enable the consumer-to-business (C2B) or business-to-business (B2B) easily interact over the website. Currently, there is no standard model is developed to facilitate the users to discover and integrate the information of facilities, resources and services that published in the libraries website. This article discussed the development of a web service model that can discover and integrate the information in the various libraries website to the users by using Java Technology application program interface and tools provided by the integrated Web Services Stack. In the modelling process, the library websites are converted into Extensive Markup Language format (XML) for examining the Simple Object Access Protocol (SOAP) of each website. The converted XML files are stored as the application data source, which lies as the core of the web service model. By using an XML parser, the XML files are parsed into XMLDOM format for manipulating its contents. XML request object hypertext protocol is used to receive or reload the data from the client to the server. Finally, HTML and cascading style sheet (CSS) are used to reload the information to the client and display it. The results show that the proposed model is able to achieve over 90% of information discovery average precision performance regarding to user’s query on facilities, resources and services provided in the library websites. The developed model can benefit library’s users to extract the resources, facilities and services provided by the library intelligently.

Сервисные средства интернет для решения бизнес-задач

Different types of global information network services, used in the modern distributed software systems are described. Several approaches to service description and to service interaction are shown. Description of wide-spread and inculcated approaches to creation of distributed object interaction is given in the wide practice of the systems with spectrum of system and functional services. Web-service international standards stack (SOAP protocol, WSDL language, UDDI interface and service, XML, BPEL and BPMN notations, CORBA object broker and services, JEE application server) is briefly described. Models of web services, service-oriented approach (SOA), service-component architectures (SCA), and Windows Communication Foundation (WCF) service support application systems are considered for presentation of the business systems by the services ready to the decision of business-tasks. Features that support interoperability and multilanguage interaction are underlined. Principles of distributed software design (service composition, component engineering, interoperability, variance) that are of special care in SOA are listed. Some examples of presenting information using standard notations are given. An additional example of calculator service with functions of the data processing in ITK service-environment (WCF-based system) and the concept of web service implementation are presented.

A QoS Perspective on Exception Diagnosis in Service-Oriented Computing

Unlike object-oriented applications it is difficult to address exceptions in multi-agent systems due to their highly dynamic and autonomous nature. Our previous work has examined exception diagnosis in multi-agent systems based on a heuristic classification method. In this paper, we extend our work by applying an exception diagnosis method to web services (WS) by proposing a unified framework for dealing with exceptions occurring in multi-agent systems as well as in web services. Importantly, we relate the impact of exceptions to Quality of Service (QoS), as exceptions normally degrade the quality of service offered to a service consumer. Our framework consists of a QoS monitoring agent that monitors all interactions taking place between service consumers and service providers. The monitoring agent encodes the knowledge of exceptions, their causes and applies the heuristic classification method for reasoning in order to diagnose underlying causes of monitored exceptions. In this paper, we categorize exceptions into three levels in multi-agent systems: Environment Level Exception; Knowledge Level Exception and Social Level Exception. This paper also discusses different classes of exceptions in web services based on the web service stack.

Are our homes ready for services? A domotic infrastructure based on the Web service stack

The increase in computational power and the networking abilities of home appliances are revolutionizing the way we interact with our homes. This trend is growing stronger and opening a number of technological challenges. From the point of view of distributed systems, there is a need to design architectures for enhancing the comfort and safety of the home, which deals with issues of heterogeneity, scalability and openness. By considering the evolution of domotic research and projects, we advocate a role for Web services in the domestic network. We ground our claim by proposing a concrete architecture for a home in which the health of an elder is monitored. The architecture is implemented on a heterogeneous set of devices, which allows us to evaluate it and draw conclusions on the feasibility of using service-oriented approaches in ubiquitous computing.

Candidate interoperability standards: An ontological overlap analysis

A web service choreography standard enables a standardized description of business processes that allows not only a clear specification of the control flow, but also forms the basis for the actual process execution. Such standards are part of the web services stack and facilitate enterprise systems interoperability. A simple indication of the rapid growth of this area is the number of new and existing standards. However, while the list of standards is expanding, there is an obvious lack of sound theoretical evaluation and comparison of these standards. To provide a basis for this theoretical evaluation and comparison, we use the well-established Bunge–Wand–Weber (BWW) models, in particular the representation model. We, and other researchers, have shown the usefulness of the BWW representation model for analyzing, evaluating, and engineering techniques in the areas of traditional and structured systems analysis, object-oriented modeling, and process modeling. In this paper, we present the BWW ontological analysis of four dominating candidate interoperability standards; ebXML Business Process Specification Schema BPSS (v1.01), the Business Process Modeling Language BPML (v1.0), the Business Process Execution Language for Web Services BPEL4WS (v1.1) and the Web Service Choreography Interface WSCI (v.1.0). The application of the BWW representation model and the overlap analysis across the four standards has resulted in several interesting findings. First, we have identified a set of ontological constructs for which representations are missing in each of the standards. This situation has allowed us to generate a number of propositions as to the potential weaknesses of the standards in general. Second, the analysis has shown that ebXML BPSS is a “clear winner” with respect to the ontological expressiveness and the maturity of the specification. Furthermore, the analysis has also allowed us to identify two sets of standards viz. ebXML BPSS and BPEL4WS, ebXML BPSS and WSCI, that, when used together, provide the user with the largest available set of meaningful constructs required to implement systems interoperability. Finally, the analysis explains which standards are complementary to each other and which standards are in fact competing standards.

Business processes for Web Services: Principles and applications

The Business Process Execution Language for Web Services (BPEL4WS or BPEL for short) is an XML-based language for defining business processes that provides an interoperable, portable language for both abstract and executable processes and that was designed from the beginning to operate in the heterogeneity and dynamism that is commonplace in information technology today. BPEL builds on the layers of flexibility provided by the Web Services stack, and especially by XML. In this paper, we provide a brief introduction to BPEL with emphasis on architectural drivers and basic concepts. Then we survey ongoing BPEL work in several application areas: adding quality of service to BPEL, extending BPEL to activities involving humans, BPEL for grid computing, and BPEL for autonomic computing.

Putting Web Services in Context

When considering the full range of Web service-related activities, it becomes clear that dealing with context is a major challenge, requiring greater expressiveness, reasoning capabilities, and architectural components than are provided by the current widely accepted building blocks of the Web services stack. This paper presents an informal overview of concepts, requirements and challenges for handling contextual knowledge in connection with Web services, and briefly discusses several interesting projects in this area of research.

STRUCTURAL AND SEMANTIC MATCHING FOR ASSESSING WEB-SERVICE SIMILARITY

The web-services stack of standards is designed to support the reuse and interoperation of software components on the web. A critical step in the process of developing applications based on web services is service discovery, i.e. the identification of existing web services that can potentially be used in the context of a new web application. Discovery through catalog-style browsing (such as supported currently by web-service registries) is clearly insufficient. To support programmatic service discovery, we have developed a suite of methods that assess the similarity between two WSDL (Web Service Description Language) specifications based on the structure of their data types and operations and the semantics of their natural language descriptions and identifiers. Given only a textual description of the desired service, a semantic information-retrieval method can be used to identify and order the most relevant WSDL specifications based on the similarity of the element descriptions of the available specifications with the query. If a (potentially partial) specification of the desired service behavior is also available, this set of likely candidates can be further refined by a semantic structure-matching step, assessing the structural similarity of the desired vs the retrieved services and the semantic similarity of their identifiers. In this paper, we describe and experimentally evaluate our suite of service-similarity assessment methods.

Colombo: Lightweight middleware for service-oriented computing

Colombo is a lightweight platform for developing, deploying, and executing service-oriented applications. It provides optimized, native runtime support for the service-oriented-computing model, as opposed to the approach of layering service-oriented applications on a legacy runtime. This approach allows Colombo to provide high runtime performance, a small footprint, and simplified application development and deployment models. The Colombo runtime natively supports the full Web Services (WS) stack, providing transactional, reliable, and secure interactions among services. It defines a multilanguage service programming model that supports, among others, JavaTM and Business Process Execution Language for Web Services (BPEL4WS) service composition, and offers a deployment and discovery model fully based on declarative service descriptions (Web Service Description Language [WSDL] and WS-Policy). In this paper we describe these and other aspects of the architecture, design principles, and capabilities of the Colombo platform.

Critics Say Web Services Need a REST

A vocal group of developers critical of the orthodox Web Services stack is touting the use of a technology called REST, or Representational State Transfer Web Services. REST advocates a more streamlined (and familiar) XML-over-HTTP approach for exposing software functionality. Here are some of the issues being debated.