Overview of Web Services

simple, flexible, text-based markup language. XML data is marked using tags enclosed in angled brackets. The tags contain the meaning of the data they mark. Such markup allows different systems to easily exchange data with each other.

A Document Type Definition (DTD) or XML Schema Definition (XSD) describes the structure of an XML document. It has information on the tags the corresponding XML document can have, the order of those tags, and so forth.

XSLT, which stands for eXtensible Stylesheet Language Transformation, is used for transforming XML documents from one format to another.

Web Services Standards

Simple Object Access Protocol (SOAP) provides a common messaging format for web services. SOAP enables objects not known to one another to exchange messages. SOAP uses an XML-based data encoding format and HTTP to transport messages. SOAP is independent of both the programming language and the operational platform, and it does not require any specific technology at its endpoints

Universal Description, Discovery, and Integration (UDDI) provides a standard way to register, de-register, and look up web services. Similar to a telephone system's yellow pages, a UDDI registry's enables providers to register their services and requestors to find services. Once a requestor finds a service, the registry has no more role to play between the requestor and the provider.

Web Services Description Language (WSDL) defines a standard way to specify the details of a web service. It is a general-purpose XML schema that can specifies details of web service interfaces, bindings, and other deployment details. By having such a standard way to specify details of a service, clients who have no prior knowledge of a web service can use it.

ebXML (Electronic Business using eXtensible Markup Language) is a set of specifications that enables enterprises to conduct business over the Internet. OASIS (Organization for the Advancement of Structured Information Standards) controls the ebXML specifications.

Java EE Web Service Standards

Java APIs for XML processing (JAXP) is a vendor-neutral set of lightweight APIs for parsing or processing XML documents. JAXP enables a web service to “plug in” any conforming XML parser. If no external parser is “plugged in,” then JAXP uses its own XML parser implementation.

Java API for XML-based remote procedure calls (JAX-RPC) uses an XML-based protocol for client-server remote procedure calls . JAX-RPC enables SOAP-based interoperable and portable web services. Developers use the JAX-RPC programming model to develop SOAP-based web

154

Sun GlassFish Enterprise Server 2.1 Administration Guide • December 2008

Page 154
Image 154
Sun Microsystems 820433510 manual Web Services Standards, Java EE Web Service Standards