Web Services - Components

Over the past few years, three primary technologies have emerged as worldwide standards that make up the core of today's web services technology. These technologies are discussed below.

XML-RPC

This is the simplest XML-based protocol for exchanging information between computers.

• XML-RPC is a simple protocol that uses XML messages to perform RPCs.
• Requests are encoded in XML and sent via HTTP POST.
• XML responses are embedded in the body of the HTTP response.
• XML-RPC is platform-independent.
• XML-RPC allows diverse applications to communicate.
• A Java client can speak XML-RPC to a Perl server.
• XML-RPC is the easiest way to get started with web services.

SOAP

SOAP is an XML-based protocol for exchanging information between computers.

• SOAP is a communication protocol.
• SOAP is for communication between applications.
• SOAP is a format for sending messages.
• SOAP is designed to communicate via Internet.
• SOAP is platform independent.
• SOAP is language independent.
• SOAP is simple and extensible.
• SOAP allows you to get around firewalls.
• SOAP will be developed as a W3C standard.

WSDL

WSDL is an XML-based language for describing web services and how to access them.

• WSDL stands for Web Services Description Language.
• WSDL was developed jointly by Microsoft and IBM.
• WSDL is an XML based protocol for information exchange in decentralized and distributed environments.
• WSDL is the standard format for describing a web service.
• WSDL definition describes how to access a web service and what operations it will perform.
• WSDL is a language for describing how to interface with XML-based services.
• WSDL is an integral part of UDDI, an XML-based worldwide business registry.
• WSDL is the language that UDDI uses.
• WSDL is pronounced as 'wiz-dull' and spelled out as 'W-S-D-L'.

UDDI

UDDI is an XML-based standard for describing, publishing, and finding web services.

• UDDI stands for Universal Description, Discovery, and Integration.
• UDDI is a specification for a distributed registry of web services.
• UDDI is platform independent, open framework.
• UDDI can communicate via SOAP, CORBA, and Java RMI Protocol.
• UDDI uses WSDL to describe interfaces to web services.
• UDDI is seen with SOAP and WSDL as one of the three foundation standards of web services.
• UDDI is an open industry initiative enabling businesses to discover each other and define how they interact over the Internet.