IT Application Development with Web Services

Author(s):  
Christos Makris ◽  
Yannis Panagis ◽  
Evangelos Sakkopoulos ◽  
Athanasios Tsakalidis

The advent of Web Services (WS) has signaled a true revolution in the way service-oriented computing and remote procedure invocation over the Web are conducted. Web Services comprise of a set of loosely coupled specifications to coordinate process execution from distance, based on common and widely accepted Web protocols such as HTTP, FTP, and XML, and therefore, providing increased development flexibility. Since the WS Framework was built on top of those protocols, Web Services have been widely acclaimed by the Web development community and paradoxically; they have marked one of the few examples in the history of computer protocols where a global consensus has been reached. The Web Service framework consists of essentially three basic components: 1. The Web Service Description Language (WSDL), a language that allows formal functional characterization of the provided functionalities; 2. The Simple Object Access Protocol (simply SOAP from its version 1.2), a protocol that defines the format of the information interchange; and 3. The UDDI (Universal Description, Discovery and Integration) is a catalog of Web Service descriptions. All three of these components are specified using XML markup. The elegance of the WS architecture lies in the fact that every WS transaction is taking place over established Web protocols such as HTTP and FTP. As remarked in Ballinger (2003, p. 5): “A Web Service is an application logic that is accessible using Internet standards.” This very fact has accounted for the rapid and universal adoption of Web Services. This work is organized as follows: First, a review of underlying technologies and tools is presented. Consequently, existing techniques for design methodologies are described. Next, an overview of storage and retrieval techniques for Web Services is given followed by real-world applications of Web Services. We conclude with open issues and discussion.

Author(s):  
M.Kiran Kumar ◽  
VJST Anirudh

Service provided by one electronic device to the other electronic device or devices is generally called as a web service. It may be a block of code that can be remotely accessed and utilized. In the present IT industry web services are playing a vital role in application development by providing a facility of using the existing modules to make up an application without coding from the scratch. This improves the productivity and reduces the overall project development cost and time. This paper provides the basic information of the components that supports the usage of web service along with the web service architecture. The components that are required for the web service architecture such as SOAP: simple object access protocol: used for establishing connection between components, UDDI (Universal Description, Discovery, and Integration):a registry that stores all the web services and WSDL: web service description language.


2019 ◽  
Vol 54 (6) ◽  
Author(s):  
Sawsan Ali Hamid ◽  
Rana Alauldeen Abdalrahman ◽  
Inam Abdullah Lafta ◽  
Israa Al Barazanchi

Recently, web services have presented a new and evolving model for constructing the distributed system. The meteoric growth of the Web over the last few years proves the efficacy of using simple protocols over the Internet as the basis for a large number of web services and applications. Web service is a modern technology of web, which can be defined as software applications with a programmatic interface based on Internet protocol. Web services became common in the applications of the web by the help of Universal, Description, Discovery and Integration; Web Service Description Language and Simple Object Access Protocol. The architecture of web services refers to a collection of conceptual components in which common sets of standard can be defined among interoperating components. Nevertheless, the existing Web service's architecture is not impervious to some challenges, such as security problems, and the quality of services. Against this backdrop, the present study will provide an overview of these issues. Therefore, it aims to propose web services architecture model to support distributed system in terms of application and issues.


Author(s):  
Carlos Granell ◽  
Laura Díaz ◽  
Michael Gould

The development of geographic information systems (GISs) has been highly influenced by the overall progress of information technology (IT). These systems evolved from monolithic systems to become personal desktop GISs, with all or most data held locally, and then evolved to the Internet GIS paradigm in the form of Web services (Peng & Tsou, 2001). The highly distributed Web services model is such that geospatial data are loosely coupled with the underlying systems used to create and handle them, and geospatial processing functionalities are made available as remote, interoperable, discoverable geospatial services. In recent years the software industry has moved from tightly coupled application architectures such as CORBA (Common Object Request Broker Architecture?Vinoski, 1997) toward service-oriented architectures (SOAs) based on a network of interoperable, well-described services accessible via Web protocols. This has led to de facto standards for delivery of services such as Web Service Description Language (WSDL) to describe the functionality of a service, Simple Object Access Protocol (SOAP) to encapsulate Web service messages, and Universal Description, Discovery, and Integration (UDDI) to register and provide access to service offerings. Adoption of this Web services technology as an option to monolithic GISs is an emerging trend to provide distributed geospatial access, visualization, and processing. The GIS approach to SOA-based applications is perhaps best represented by the spatial data infrastructure (SDI) paradigm, in which standardized interfaces are the key to allowing geographic services to communicate with each other in an interoperable manner. This article focuses on standard interfaces and also on current implementations of geospatial data processing over the Web, commonly used in SDI environments. We also mention several challenges yet to be met, such as those concerned with semantics, discovery, and chaining of geospatial processing services and also with the extension of geospatial processing capabilities to the SOA world.


2013 ◽  
Vol 4 (1) ◽  
pp. 8-11
Author(s):  
Mrs. M. Akila Rani ◽  
Dr. D. Shanthi

Web mining is the application of data mining techniques to discover patterns from the Web. Web services defines set of standards like WSDL(Web Service Description Language), SOAP(Simple Object Access Protocol) and UDDI(Universal Description Discovery and Integration) to support service description, discovery and invocation in a uniform interchangeable format between heterogeneous applications. Due to huge number of Web services and short content of WSDL description, the identification of correct Web services becomes a time consuming process and retrieves a vast amount of irrelevant Web services. This emerges the need for the efficient Web service mining framework for Web service discovery. Discovery involves matching, assessment and selection. Various complex relationships may provide incompatibility in delivering and identifying efficient Web services. As a result the web service requester did not attain the exact useful services. A research has emerged to develop method to improve the accuracy of Web service discovery to match the best services. In the discovery of Web services there are two approaches are available namely Semantic based approach and Syntactic based approach. Semantic based approach gives high accuracy than Syntactic approach but it takes high processing time. Syntactic based approach has high flexibility. Thus, this paper presents a survey of semantic based and syntactic based approaches of Web service discovery system and it proposed a novel approach which has better accuracy and good flexibility than existing one. Finally, it compares the existing approaches in web service discovery.


2007 ◽  
pp. 244-267
Author(s):  
Bernd Aman ◽  
Salima Benbernou ◽  
Benjamin Nguyen

Unlike traditional applications, which depend upon a tight interconnection of all program elements, Web service applications are composed of loosely coupled, autonomous and independent services published on the Web. In this chapter, we first introduces the concept of service oriented computing (SOC) on the Web and the current standards enabling the definition and publication of Web services. This technology’s next evolution is to facilitate the creation and maintenance of Web applications. This can be achieved by exploiting the self-descriptive nature of Web services combined with more powerful models and languages for composing Web services. A second objective of this chapter is to illustrate the complexity of the Web service composition problem and to provide a representative overview of the existing approaches. The chapter concludes with a short presentation of two research projects exploiting and extending the Web service paradigm.


2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Chengai Sun ◽  
Liangyu Lv ◽  
Gang Tian ◽  
Qibo Wang ◽  
Xiaoning Zhang ◽  
...  

Information retrieval-based Web service discovery approach suffers from the semantic sparsity problem caused by lacking of statistical information when the Web services are described in short texts. To handle this problem, external information is often utilized to improve the discovery performance. Inspired by this, we propose a novel Web service discovery approach based on a neural topic model and leveraging Web service labels. More specifically, words in Web services are mapped into continuous embeddings, and labels are integrated by a neural topic model simultaneously for embodying external semantics of the Web service description. Based on the topic model, the services are interpreted into hierarchical models for building a service querying and ranking model. Extensive experiments on several datasets demonstrated that the proposed approach achieves improved performance in terms of F-measure. The results also suggest that leveraging external information is useful for semantic sparse Web service discovery.


Author(s):  
Houda el Bouhissi ◽  
Mimoun Malki ◽  
Mohamed Amine Sidi Ali Cherif

The growing number of the Web Services available on the Web without explicit associated semantic descriptions raises a new and challenging research problem: How to discover efficiently the relevant Web Services that fulfill the user expectations. However, many services that are relevant to a specific user service request may not be considered during the service discovery process. In this paper, the authors address the issue of the Web Service discovery given nonexplicit service description semantics that match a specific service request. Their approach is based on a captured user goal from an HTML form and the traceability and involves semantic-based service categorization, semantic discovery and selection of the best Web Service. Furthermore, the authors' proposal employs ontology matching algorithms to match a specific goal to an existing Web Service. An experimental test of the proposed framework related to the Medical Analysis domain is reported, showing the impact of the proposal in decreasing the time and the effort of the discovery process as a whole.


2010 ◽  
pp. 193-221 ◽  
Author(s):  
Enrico Pontelli ◽  
Tran Cao Son ◽  
Chitta Baral

This chapter presents a comprehensive logic programming framework designed to support intelligent composition of Web services. The underlying model relies on the modeling of Web services as actions, each described by a logic programming theory. This view allows the use of logic-based planning to address the Web service composition problem, taking advantage of the fact that logic-based planning enables the elegant introduction of a number of extensions and generalizations (e.g., dealing with incomplete knowledge and preferences). The theory describing each Web service is encoded as a logic programming module, and different semantics are allowed within different modules, thus better reflecting the practical use of different service description formalisms and ontologies.


Author(s):  
Radhika Jain ◽  
Balasubramaniam Ramesh

A Web service is an interface that describes a collection of operations that are network accessible through standardized XML (extensible markup language) messaging specifications such as SOAP, WSDL (Web service description language), and UDDI to provide open, XML-based mechanisms for application interoperability, service description, and service discovery (Kim & Jain, 2005). They are self-contained, modular units of application logic that provide business functionality to other applications via an Internet connection (Srivastava & Koehler, 2003). Although Web services are a relatively new concept, they provide a solution to the set of serious problems that have plagued enterprise systems using a service-oriented architecture (SOA). Web services address a similar set of problems that middleware technologies such as CORBA, RPC, COM, and RMI address by providing a tightly coupled and vendor-driven proprietary environment for implementing SOA.


2008 ◽  
pp. 138-161
Author(s):  
Rafae Bhatti ◽  
Daniel Sanz ◽  
Elisa Bertino ◽  
Arif Ghafoor

This chapter describes a policy-based authorization framework to apply fine-grained access control on Web services. The framework is designed as a profile of the well-known WS-Policy specification tailored to meet the access control requirements in Web services by integrating WS-Policy with an access control policy specification language, X-GTRBAC. The profile is aimed at bridging the gap between available policy standards for Web services and existing policy specification languages for access control. The profile supports the WS-Policy Attachment specification, which allows separate policies to be associated with multiple components of a Web service description, and one of our key contributions is an algorithm to compute the effective policy for the Web service given the multiple policy attachments. To allow Web service applications to use our solution, we have adopted a component-based design approach based on well-known UML notations. We have also prototyped our architecture in a loosely coupled Web services environment.


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