10-04-2017, 09:17 PM
Abstract:
According to the W3C a Web service] is a software system designed to support interoperable machine-to-machine interaction over a network. It has an interface that is described in a machine-processible format such as WSDL. Other systems interact with the Web service in a manner prescribed by its interface using messages, which may be enclosed in a SOAP envelope, or follow a RESTful approach. These messages are typically conveyed using HTTP, and normally comprise XML in conjunction with other Web-related standards. Software applications written in various programming languages and running on various platforms can use web services to exchange data over computer networks like the Internet in a manner similar to inter-process communication on a single computer. This interoperability (for example, between Java and Python, or Microsoft Windows and Linux applications) is due to the use of open standards. OASIS and the W3C are the primary committees responsible for the architecture and standardization of web services. To improve interoperability between web service implementations, the WS-I organization has been developing a series of profiles to further define the standards involved.
[attachment=1860]
ABSTRACT
According to the W3C a Web service] is a software system designed to support interoperable machine-to-machine interaction over a network. It has an interface that is described in a machine-processible format such as WSDL. Other systems interact with the Web service in a manner prescribed by its interface using messages, which may be enclosed in a SOAP envelope, or follow a RESTful approach. These messages are typically conveyed using HTTP, and normally comprise XML in conjunction with other Web-related standards. Software applications written in various programming languages and running on various platforms can use web services to exchange data over computer networks like the Internet in a manner similar to inter-process communication on a single computer. This interoperability (for example, between Java and Python, or Microsoft Windows and Linux applications) is due to the use of open standards. OASIS and the W3C are the primary committees responsible for the architecture and standardization of web services. To improve interoperability between web service implementations, the WS-I organization has been developing a series of profiles to further define the standards involved.
Motivation
INTRODUCTION
The ability to program the Web Example: Consider an Excel spreadsheet that summarizes your Whole financial picture : stocks, bank accounts, loans, etc. If some of this information is available through XML Web services, Excel can update it and present the update information to the user Web services evolved from previous technologies that served the same purpose such as RPC, ORPC (DCOM, CORBA and JAVA Web Services were intended to. solve three main problems: lnteroperability Firewall traversal
Advantages of Web Services
Web services provide interoperability between various software applications running on disparate platforms/operating systems. Web services use open standards and protocols. Protocols and data I: formats are text-based where possible, making it easy for developers to comprehend. By utilizing HTTP, web services can work through many common firewall security measures without requiring changes to the firewall filtering rules. Other forms of RPC may more often be blocked. Web services allow software and services from different companies and locations to be combined easily to provide an integrated service. Web services allow the reuse of services and components within an infrastructure. = Web services are loosely coupled thereby facilitating a distributed I approach to application integration.
Disadvantages of Web Services
Web services standards features such as transactions are currently nonexistent or still in their infancy compared to more mature distributed computing open standards such as CORBA. This is likely to be a temporary disadvantage as most vendors have committed to the OASIS standsrds to implement the Quality of Service aspects of Web services may suffer from poor performance compared to other distributed computing approaches such as RMI, CORBA, or DCOM. This is a common trade-off when choosing text-based formats. XML explicitly does not count among its design goals either conciseness of encoding or efficiency of parsing. This could change with the XML lnfoset standard, which describes XML-based languages in terms of abstractions (elements, attributes, logical nesting). The traditional angle-bracket representation is now seen as an ASCII (or Unicode) serialisation of XML, not XML itself. In this model, binary serialisation is an equally valid alternative. Binary representations such as SOAP MTOM promise to improve the wire efficiency of XML messaging: