What is SOAP?SOAP : Simple Object Oriented Protocol
1. It is a stateless, platform independent, XML based generic lightweight protocol that uses HTTP as its transport medium and can be used for developing distributed complex computing environments.
2. Application can communicate directly with each other over the internet using SOAP.
3. It allows exchange of data between heterogeneous web applications.
SOAP supports RPC like the DCOM or CORBA but it uses the XML Open Standard for the purpose of data exchange between homogenous or heterogeneous distributed applications.
4. Because of its platform independence, language independence and the usage og message communication, the SOAP protocol is robust and standardized mechanism over homogenous or heterogeneous networks.
5. In the Remote Procedure Call of SOAP, the client sends a request message to the server. The server in turn sends the response message to the client.
6. XML is the foundation of the SOAP activities. All SOAP messages are transmitted in XML format and is a standard for the representation and interchange of data in structured form across systems.
Why is SOAP required?- The protocols like DCOM, RPC, IIOP are limited to a homogenous network. However, distributed applications comprise of a heterogeneous network components which necessitates the information to be transferred in common data format across the platforms.
- Simple Object Oriented Protocol (SOAP) is an Open Standard protocol and used XMl which has already been accepted as a standard form of information transfer which makes the usage of SOAP a solution to the complexity.
Advantages of SOAPThe following are some of the many advantages that SOAP provides.
1. Language neutrality :SOAP can be developed using any language.
2. Interoperability and Platform Independence : SOAP can be implemented in any language and can be executed in any platform.
3. Simplicity : SOAP messages are in very simple XML format.
4. Scalability : SOAP uses HTTP protocol for transport due to which it becomes scalable.
Disadvantages of SOAP.The following are the disadvantages of SOAP.
1. Slow : SOAP uses the XML format which needs to be parsed and is lengthier too which makes SOAP slower than CORBA, RMI or IIOP.
2. WSDL Dependence : It depends on WSDL and does not have any standardized mechanism for dynamic discovery of the services.
Composition of SOAP.As per the SOAP specification, SOAP is typically composed of the following three parts:
1. A framework : It describes the way for the construction and processing of the messages.
2. A set of encoding rules : These are used for exchanging the data types.
3. A convention and a procedure for representing the Remote Procedure Calls.