Designing level 3 behavioral RESTful web service interfaces

Web service interfaces are considered as one of the critical components of a Service-Oriented Architecture (SOA) and they represent contracts between web service providers and clients (subscribers). These interfaces are frequently modified to meet new requirements. However, these changes in a web service interface typically affect the systems of its subscribers. Thus, it is important for subscribers to estimate the risk of using a specific service and to compare its evolution to other services offering the same features in order to reduce the effort of adapting their applications in the next releases. In addition, the prediction of interface changes may help web service providers to better manage available resources (e.g. programmers’ availability, hard deadlines, etc.) and efficiently schedule required maintenance activities to improve the quality. In this paper, we propose to use machine learning, based on Artificial Neuronal Networks, for the prediction of the evolution of Web services interface design. To this end, we collected training data from quality metrics of previous releases from 6 Web services. The validation of our prediction techniques shows that the predicted metrics value, such as number of operations, on the different releases of the 6 Web services were similar to the expected ones with a very low deviation rate. In addition, most of the quality issues of the studied Web service interfaces were accurately predicted, for the next releases, with an average precision and recall higher than 82 %. The survey conducted with active developers also shows the relevance of prediction technique for both service providers and subscribers.

Service Oriented Architecture (SOA) has been widely adopted by industries due to its ability to provide increased interoperability among heterogeneous systems. SOA is realized through web services which can be either based on the style of Remote Procedure call(RPC) and SOAP protocol or on the Representational State Transfer(REST) style and HTTP. RESTful web services are increasingly becoming popular in the industry because of their simplicity, uniform interface, statelessness and cacheability benefits. The ability to efficiently select and integrate appropriate heterogeneous services available on the web dynamically at runtime is essential in the development of the applications based on web services. Whenever a single web service cannot satisfy the functionality required by the user, there should be a possibility to combine several existing services together in order to fulfill the request. This need has triggered a considerable number of research efforts on the composition of web services. Although several works have focused on the composition of SOAP based web services, there has not been adequate effort towards the composition of RESTful services. However, due to the above- mentioned advantages offered by the RESTful web services, it will be beneficial to design an application as a composition of such RESTful services. Towards this objective, this paper investigates two different approaches for composing the REStful web services specifically designed for health care domain, one using the Jopera tool and another using hypermedia.

Source-code comprehension tasks supported by UML design models: Results from a controlled experiment and a differentiated replication

Internet is providing the platform for accessing different kinds of services in a distributed and heterogeneous environment. Software components are available on Internet in the form of Web Services. Service Oriented Architecture (SOA) possesses various characteristics by executing Web Services using Simple Object Access Protocol (SOAP). SOAP has certain limitations such as tightly coupled invocation, performance in terms of response data, non-uniform interface and no hyperlink support. These limitations can be resolved by implementing principles of Representational State Transformation (REST). REST is an architectural style implemented by resources known as RESTful Web Services. At present, light-weight RESTful services are dominating the development of services due to simplicity of RESTful architecture. Service access and invocation is simple in RESTful framework as it uses Uniform Resource Identifier (URIs) and Hyperlinks. In this paper, we explore the idea of RESTful Service Mashup by integrating individual Web Services which can satisfy end users' requirements. For this work, we propose a recursive algorithm. The implementation work is on Android 2.2 (froyo), API level 8 and above. It is supported on most of Android based mobile devices.

In today`s world of science & technology mobile device especially Smartphones plays the role of “"Jinn" who fulfill demand of the user. Smartphone through its Internet facility allows users to access various internet based web services ubiquitously to fulfill his/her demand. Web Services can be of two types SOAP or Restful services. Many researchers have mentioned that SOAP based services are heavy to consume on mobile device despite the fact that most of the companies still uses SOAP services but answer to this challenge is Restful Web Services. Restful services also surfers from many problems like processing of work or accessing services on device due to mobile phone`s small screen size, low processing power, less memory storage capacity etc. That`s why the heavy processing work is shifted on Cloud and only client part will be on mobile device, this integration is called as Mobile Cloud Computing (MCC). In MCC important point need to consider is to improve the performance of web services in terms of speed, memory usage and reducing latency. To resolve these issues, this paper has proposed MCC architecture. We have divided this paper is into two parts, in the first part; we did comparative analysis of Web Service consumption on mobile devices using cloud and various parameters used. In second part we have proposed architecture for mobile Web Services in Cloud which compress response data using Gzip and use of web caching to reduce overhead of repeated or previously accessed Web Service.

With the rapid development of Internet, Web Service technology is gradually applied to many areas of life. The security problems occurred in practical applications of Web Service has received more and more attention from the public. Aiming at the security problems existing in the application process of Web Service, a secure real-time internal and external network data exchange method based on Web Service protocol is proposed in this paper, it is agreed that the external network only allows data exchange with the internal network through the Web Service interface, that is, the internal network starts the Web Service service, the external network accesses the service, and then obtains the internal network data or informs the internal network for business processing. Web attack detection is put to the front end to ensure maximum security of Web Service system, which can meet the requirements of more secure and robust web applications while guaranteeing the business security of visitors.

We present a language for specifying web service interfaces. A web service interface puts three kinds of constraints on the users of the service. First, the interface specifies the methods that can be called by a client, together with types of input and output parameters; these are called signature constraints. Second, the interface may specify propositional constraints on method calls and output values that may occur in a web service conversation; these are called consistency constraints. Third, the interface may specify temporal constraints on the ordering of method calls; these are called protocol constraints. The interfaces can be used to check, first, if two or more web services are compatible, and second, if a web service A can be safely substituted for a web service B. The algorithm for compatibility checking verifies that two or more interfaces fulfill each others' constraints. The algorithm for substitutivity checking verifies that service A demands fewer and fulfills more constraints than service B.

It is common that multiple Web services coordinate to achieve a common goal. If two Web services happen to reside on the same runtime system, it is inefficient to communicate via Web services interface. This research proposes our short circuit switch (SCS), which is an intelligent Web services discovery and invocation engine that can be attached to deployed Web services. Our preliminary empirical experience shows that our short circuit switch engine exhibits high performance.

UML-based approaches provide abstraction to deal with the high complexity of embedded applications and when combined with Model-driven Engineering can also provide automation trough automatic code generation. This paper presents an approach to automatically generate structural and behavioral code from UML class and sequence diagrams.This approach is demonstrated through a case study and was validated by the implementation of a code generator.

SOA and Web Services allow to easily expose business functions to build larger distributed systems. However, legacy systems – mostly in COBOL – are left aside unless applying a migration approach. Main approaches are: direct and indirect migration. The former implies to wrap COBOL programs with a thin layer of a Web Service oriented language/platform. The latter needs reengineering COBOL functions to a modern language/platform. In a previous work, we presented an intermediate approach based on direct migration where developed Web Services are later refactored to improve their interfaces quality. Refactorings mainly capture good practices inherent to indirect migration. In this paper, we measure the complexity of Web Services’ interfaces generated by the three approaches. Both comprehension and interoperability can be affected according to the service interface complexity level. We apply a metric suite (by Baski & Misra) to measure complexity on services interfaces – i.e., WSDL documents. Migrations of two real COBOL systems upon the three approaches were compared on the complexity level of the generated WSDL documents.

Interface and interaction design take up most of the times in software creation. Human Computer Interaction (HCI) is mainly the best way to interact with a computer. During software development, class diagram is the only required step and process to design an information system according to UML notation. In addition, creating class diagram is a mandatory activity during the software creation process. The aim of this paper is to automatically generate the HCI mockup from class diagram to make easy and extremely fast software design. For example, the SEF (Schéma d'Enchaînement de Fenêtre), is an interface model allowing to create a new interface mockup. It offers more widgets to design the HCI. And MACAO (Méthode d'Analyse et de Conception d'Applications Orientées-objets) is one of the methods which helps computer scientist to easily create software. The model transformation is based on Model Driven Engineering (MDE). We use UML notation to design the class diagrams. We also adopt MDA architecture to create the model-based transformation process. Transformation rules are created using Atlas Transformation Language (ATL) to automatically generate a specific interface from the class diagram.

ABSTRACTUML class diagrams are used in order to demonstrate the model information systems. Most of the former systems were previously framed by applying UML class diagrams. Besides, the current trend has a growing demand of reusing data from older information systems, which is very beneficial for the implementation of semantic knowledge. The upgradation and conversion of UML class diagrams into ontology aim to reuse older systems; therefore, cost reduction is essential. There have been many studies for transformation from UML class diagrams into ontology; however, they have not fully proposed the transformation rules. This paper will suggest the addition of rules for transforming UML class diagrams to ontologies, such as attribute transformations which have data types as classes, the structured attributes, the association with association class, the recursive association, the aggregation with a qualification.

JSON (JavaScript Object Notation) is a lightweight data-interchange format for the Internet. JSON is built on two structures: (1) a collection of name/value pairs and (2) an ordered list of values (http://www.json.org/). Because of this simple approach, JSON is easy to use and it has the potential to be the data interchange format of choice for the Internet. Similar to XML, JSON schemas allow nested structures to model hierarchical data. As data interchange over the Internet increases exponentially due to cloud computing or otherwise, redundancy free JSON data are an attractive form of communication because they improve the quality of data communication through eliminating update anomaly. Nested Normal Form, a normal form for hierarchical data, is a precise characterization of redundancy. A nested table, or a hierarchical schema, is in Nested Normal Form if and only if it is free of redundancy caused by multivalued and functional dependencies. Using Nested Normal Form as a guide, this paper introduces a JSON schema design methodology that begins with UML use case diagrams, communication diagrams and class diagrams that model a system under study. Based on the use cases’ execution frequencies and the data passed between involved parties in the communication diagrams, the proposed methodology selects classes from the class diagrams to be the roots of JSON scheme trees and repeatedly adds classes from the class diagram to the scheme trees as long as the schemas satisfy Nested Normal Form. This process continues until all of the classes in the class diagram have been added to some JSON scheme trees.

MPI-based parallel applications including scientific applications are now widely executed on clusters and grids, and great benefits have been brought to scientific community. However, writing parallel applications would not be easy even for experienced programmers. In this paper, we propose the design and implementation of the MPI-SV middleware that connects gSOAP, the web service interface, and MPICH, the parallel software tool running on a Rocks cluster. With MPI-SV, users can automatically call parallel functions executed on a cluster as if they were regular functions. Hence, users do not have to write MPI-based parallel functions themselves.MPI-SV middleware is implemented on a Rocks cluster and complies with the SOAP standard specification so that it could interoperable with other web services. Three experiments based on numerical calculations are conducted, and the results show that the response time is increased when the data size increases. Even though sending data in MPI-SV via XML in SOAP incurs high communication overhead, our experimental results show that, for a parallel application requiring high computation, the overhead time would be low when compared with computation time. Thus, MPI-SV would give good performance for applications that the computation time dominates the communication time, and fortunately most scientific applications have high computation.

The number of web services available on the Internet has grown rapidly. Service consumers face a hard decision over which service to choose among the available ones. Security holds a key after various vulnerabilities have been exploited by attackers on number of notable web services. This paper carries out a survey on how security has been expressed and promised for web services, through both the Web Service Description Language and Service Level Agreements. It reviews existing technologies used for comparing individual web services, as well as for service compositions. Taking security into account further complicates the already difficult process of choosing the right service. The paper reveals that despite existing efforts, a quantitative solution needs to be established urgently in order to help service consumers to choose the most secure service for them to use.