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CORBA and Object Technologies

Christopher Browne

Table of Contents
1. SOAP - Simple Object Access Protocol

1. SOAP - Simple Object Access Protocol

I am coauthor of the book Professional Open Source Web Services on the subject...

1.1. Introduction to SOAP

SOAP: Simple Object Access Protocol defines an RPC mechanism using XML for client-server interaction across a network by using several mechanisms.

The name is somewhat misleading, as, over time, it is most definitely becoming less "Simple," and because it's not terribly much about Objects, as such. Objects are typically things that have identity, contain data, and on which one invokes methods. With SOAP, you typically don't have a 'thing with identity;' you're really just calling remote methods via an RPC scheme. Some common SOAP services such as stock quote services have nothing that would be identifiable from the protocol point of view as an object.

  • HTTP as the base transport

  • XML documents for encoding of invocation requests and responses

  • Web Service Definition Language (WSDL)

    WSDL is an XML format for describing network services as a set of endpoints operating on messages containing either document-oriented or procedure-oriented information. The operations and messages are described abstractly, and then bound to a concrete network protocol and message format to define an endpoint. Related concrete endpoints are combined into abstract endpoints (services). WSDL is extensible to allow description of endpoints and their messages regardless of what message formats or network protocols are used to communicate, however, the only bindings described in this document describe how to use WSDL in conjunction with SOAP 1.1, HTTP GET/POST, and MIME.

    It essentially corresponds to the CORBA IDL language, defining what methods are available, and what are the names and types of their arguments.

  • UDDI

    Universal Description, Discovery and Integration (UDDI) - (Essentially like CORBA Trading Service, but does data transfer using SOAP)

    See also UDDI: Specifications

  • Web Services Inspection Language (WS-Inspection) 1.0

    For retrieving service description documents, and is a key component of the overall Web services model. Service discovery is a very broad concept, which means that it is unlikely to have one solution that addresses all of its requirements. The Universal Description, Discovery and Integration (UDDI) specification addresses a subset of the overall requirements by using a centralized service discovery model. This article will provide an overview of the Web Services Inspection Language (WS-Inspection), which is another related


    Reliable HTTP Protocol

  • WSFL - Web Services Flow Language

    Rather like WorkFlow for IBM Web Services

  • WSUI- Web Service User Interface

    This document describes the syntax and semantics of Web Service User Interface (WSUI). WSUI is a component model for adding presentation and multistage interaction to XML and SOAP-based network services. WSUI is designed to be lightweight and easily implementable by using standard XML technologies such as XSLT, XPath, and XHTML.

  • SOAP Attachments


    A discussion of similarities and differences between CORBA and SOAP.

  • SoapWare.Org : A Busy Developer's Guide to SOAP 1.1

1.2. SOAP Implementations

1.3. More SOAP

1.5. Layered XML Security Standards

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