SOAP
- SOAP (Simple Object Access Protocol) is a protocol specification for exchanging structured information in the implementation of Web Services in computer networks. It relies on Extensible Markup Language (XML) as its message format, and usually relies on other Application Layer protocols (RPC and HTTP) for message negotiation and transmission.
- SOAP can form the foundation layer of a web services protocol stack, providing a basic messaging framework upon which web services can be built.
- SOAP makes use of an internet application layer protocol as a transport protocol.
- A SOAP message could be sent to a web service enabled web site (for example, a house price database) with the parameters needed for a search. The site would then return an XML-formatted document with the resulting data (prices, location, features, etc). Because the data is returned in a standardized machine-parseable format, it could then be integrated directly into a third-party site.
Advantages of SOAP
- SOAP is versatile enough to allow for the use of different transport protocols. The standard stacks use HTTP as a transport protocol, but other protocols are also usable (e.g., SMTP).
- SOAP is platform independent.
- SOAP is language independent.
Disadvantages of SOAP
- Because of the verbose XML format, SOAP can be considerably slower than competing middleware technologies such as CORBA. This may not be an issue when only small messages are sent.
- When relying on HTTP as a transport protocol, the roles of the interacting parties are fixed. Only one party (the client) can use the services of the other. Developers must use polling instead of notification in these common cases.
