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25-480: The Bath Profile is an international Z39.50 Specification for Library Applications and Resource Discovery. The Bath Profile is maintained by Library and Archives Canada . The syntax of Z39.50 is abstracted from the underlying database structure. For example, if the client specifies an author search using attribute 1003, the server must determine how to map that search to the indexes it contains. This allows Z39.50 queries to be formulated without knowing anything about

50-498: A network address over the Web with the service always-on as in the concept of utility computing. Many organizations use multiple software systems for management. Different software systems often need to exchange data with each other, and a Web service is a method of communication that allows two software systems to exchange this data over the Internet. The software system that requests data

75-449: A file called WSDL (Web Services Description Language), which has a .wsdl extension. (Proposals for Autonomous Web Services ( AWS ) seek to develop more flexible Web services that do not rely on strict rules. ) A directory called UDDI (Universal Description, Discovery, and Integration) defines which software system should be contacted for which type of data. So when one software system needs one particular report/data, it would go to

100-474: A message format and SOAP/HTTP in enveloping and transporting. Functional and non-functional testing of Web services is done with the help of WSDL parsing. Regression testing is performed by identifying the changes made to upgrade software. Web service regression testing needs can be categorized in three different ways, namely, changes in WSDL, changes in the code, and selective re-testing of operations. We can capture

125-433: A reduced test suite from the old test suite. Web services testing can also be automated using several test automation tools like SoapUI , Oracle Application Testing Suite (OATS), Unified Functional Testing, Selenium, etc. Work-related to the capture and visualization of changes made to a Web service. Visualization and computation of changes can be done in the form of intermediate artifacts (Subset WSDL). The insight on

150-412: A web service commonly provides an object-oriented web-based interface to a database server, utilized for example by another web server, or by a mobile app , that provides a user interface to the end-user. Many organizations that provide data in formatted HTML pages will also provide that data on their server as XML or JSON, often through a Web service to allow syndication . Another application offered to

175-518: Is a pre- Web technology, and various working groups are attempting to update it to fit better into the modern environment. These attempts fall under the designation ZING (Z39.50 International: Next Generation), and pursue various strategies. The successors to Z39.50 are the twin protocols SRU / SRW ( Search/Retrieve via URL / Search/Retrieve Web service ), which drop the Z39.50 communications protocol (replacing it with HTTP ) while still attempting to preserve

200-642: Is an architecture for well-behaved Web services that can function at Internet scale. In a 2004 document, the W3C sets following REST as a key distinguishing feature of Web services: We can identify two major classes of Web services: There are a number of Web services that use markup languages: A Web API is a development in Web services where emphasis has been moving to simpler representational state transfer (REST) based communications. Restful APIs do not require XML-based Web service protocols ( SOAP and WSDL) to support their interfaces. In relation to W3C Web services,

225-571: Is called a service requester , whereas the software system that would process the request and provide the data is called a service provider . Different software may use different programming languages, and hence there is a need for a method of data exchange that doesn't depend upon a particular programming language. Most types of software can, however, interpret XML tags. Thus, Web services can use XML files for data exchange. Rules for communication with different systems need to be defined, such as: All of these rules for communication are defined in

250-714: Is the Bath Profile . It was named after Bath , England, where the working group first met in 1999. The document rigidly specifies the search syntax for common bibliographic searches, and the expected response of Bath-compliant servers. Implementation of the Bath Profile has been slow but is gradually improving the Z39.50 landscape. Z39.50 Z39.50 is widely used in library environments, for interlibrary catalogue search and loan , often incorporated into integrated library systems and personal bibliographic reference software , and social media such as LibraryThing . Work on

275-608: The W3C defined a Web service as: A web service is a software system designed to support interoperable machine-to-machine interaction over a network. It has an interface described in a machine-processable format (specifically WSDL ). Other systems interact with the web service in a manner prescribed by its description using SOAP-messages, typically conveyed using HTTP with an XML serialization in conjunction with other web-related standards. W3C Web Services may use SOAP over HTTP protocol, allowing less costly (more efficient) interactions over

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300-468: The XML , SOAP, WSDL and UDDI open standards over an Internet Protocol backbone. XML is the data format used to contain the data and provide metadata around it, SOAP is used to transfer the data, WSDL is used for describing the services available and UDDI lists what services are available. A Web service is a method of communication between two electronic devices over a network. It is a software function provided at

325-511: The Internet than via proprietary solutions like EDI/B2B. Besides SOAP over HTTP, Web services can also be implemented on other reliable transport mechanisms like FTP . In a 2002 document, the Web Services Architecture Working Group defined a Web services architecture, requiring a standardized implementation of a "Web service." The term "Web service" describes a standardized way of integrating Web-based applications using

350-580: The SOAP protocol. Automated tools can aid in the creation of a Web service. For services using WSDL, it is possible to either automatically generate WSDL for existing classes (a bottom-up model) or to generate a class skeleton given existing WSDL (a top-down model). Critics of non-RESTful Web services often complain that they are too complex and based upon large software vendors or integrators, rather than typical open source implementations. There are also concerns about performance due to Web services' use of XML as

375-458: The UDDI and find out which other systems it can contact for receiving that data. Once the software system finds out which other systems it should contact, it would then contact that system using a special protocol called SOAP (Simple Object Access Protocol). The service provider system would first validate the data request by referring to the WSDL file, and then process the request and send the data under

400-470: The Z39.50 protocol began in the 1970s, and led to successive versions in 1988, 1992, 1995 and 2003. The Contextual Query Language (formerly called the Common Query Language) is based on Z39.50 semantics. The protocol supports search, retrieval, sort, and browse. Search queries contain attributes, typically from the bib-1 attribute set which defines six attributes to specify information searches on

425-513: The above three needs in three intermediate forms of Subset WSDL, namely, Difference WSDL (DWSDL), Unit WSDL (UWSDL), and Reduced WSDL (RWSDL), respectively. These three Subset WSDLs are then combined to form Combined WSDL (CWSDL) that is further used for regression testing of the Web service. This will help in Automated Web Service Change Management (AWSCM), by performing the selection of the relevant test cases to construct

450-487: The benefits of the query syntax. SRU is REST -based, and enables queries to be expressed in URL query strings; SRW uses SOAP . Both expect search results to be returned as XML . These projects have a much lower barrier to entry for developers than the original Z39.50 protocol, allowing the relatively small market for library software to benefit from the web service tools developed for much larger markets. Alternatives include

475-573: The computation of change impact is helpful in testing, top-down development and reduce regression testing. AWSCM is a tool that can identify subset operations in a WSDL file to construct a subset WSDL. While UDDI was intended to serve as a service directory and become the means to discovering web services, many vendors discontinued their UDDI solutions or repositories between 2005-2008, including Microsoft, SAP, IBM, among others. A key study published in WWW2008 Conference (Beijing, China) presented

500-533: The end-user may be a mashup , where a Web server consumes several Web services at different machines and compiles the content into one user interface. Asynchronous JavaScript and XML (AJAX) is a dominant technology for Web services. Developing from the combination of HTTP servers, JavaScript clients and Plain Old XML (as distinct from SOAP and W3C Web Services), now it is frequently used with JSON as well as, or instead of, XML. Representational State Transfer (REST)

525-490: The following. The registered network port number for Z39.50 is 210. Although the majority of servers use this port, there are dozens of other port numbers used worldwide by Z39.50 (e.g. 2100, 2200, 2210, 2213, 3520, or in one case, ports 2101 and higher for different databases). Web service A web service ( WS ) is either: In a web service, a web technology such as HTTP is used for transferring machine-readable file formats such as XML and JSON. In practice,

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550-436: The inconsistency is the Bath Profile (named after Bath , England, where the working group first met in 1999). This document rigidly specifies the search syntax to employ for common bibliographic searches, and the expected response of Bath-compliant servers. Implementation of the Bath Profile has been slow but is gradually improving the Z39.50 landscape . The Bath Profile is maintained by Library and Archives Canada . Z39.50

575-407: The server computer: use, relation, position, structure, truncation, completeness. The syntax of Z39.50 allows for very complex queries. In practice, the functional complexity is limited by the uneven implementations by developers and commercial vendors. The syntax of Z39.50 is abstracted from the underlying database structure. For example, if the client specifies an author search using attribute 1003,

600-535: The server must determine how to map that search to the indexes it contains. This allows Z39.50 queries to be formulated without knowing anything about the target database, but it also means that results for the same query can vary widely among different servers. One server may have an author index and another may use its index of personal names, whether they are authors or not. A third may have no name index and fall back on its keyword index, and yet another may have no suitable index and return an error. An attempt to remedy

625-402: The target database, but it also means that results for the same query can vary widely among different servers. One server may have an author index and another may use its index of personal names, whether they are authors or not. A third may have no name index and fall back on its keyword index, and yet another may have no suitable index and return an error. An attempt to remedy this inconsistency

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