Friday, April 9, 2010


This is coming from an article on InfoQ.
REST approach, which uses a standard URI (Uniform Resource Identifier) that makes a call to a web service like http| The approach is very simple to understand and can be executed on really any client or server that has HTTP/HTTPS support. The command can execute using the HTTP Get method. So developers that use this approach, cite the ease of development, use of the existing web infrastructure.
Using SOAP 1.2 has some additional overhead that is not found in the REST approach, but that overhead also has advantages. First, SOAP relies on XML (Extensible Markup Language) in three ways; the Envelope – that defines what is in the message and how to process it, a set of encoding rules for datatypes, and finally the layout of the procedure calls and responses gathered. This envelope is sent via a transport (HTTP/HTTPS), and an RPC (Remote Procedure Call) is executed and the envelope is returned with information in a XML formatted document.
It is important to note that one of the advantages of SOAP is the use of the “generic” transport. While REST today uses HTTP/HTTPS, SOAP can use almost any transport to send the request, using everything from the afore mentioned to SMTP (Simple Mail Transfer Protocol) and even JMS (Java Messaging Service). However, one perceived disadvantage is the use of XML because of the verboseness of it and the time it takes to parse.
REST works really well for are:
  • Limited bandwidth and resources; remember the return structure is really in any format (developer defined). Plus, any browser can be used because the REST approach uses the standard GET, PUT, POST, and DELETE verbs. Again, remember that REST can also use theXMLHttpRequest object that most modern browsers support today, which adds an extra bonus of AJAX.
  • Totally stateless operations; if an operation needs to be continued, then REST is not the best approach and SOAP may fit it better. However, if you need stateless CRUD (Create, Read, Update, and Delete) operations, then REST is it.
  • Caching situations; if the information can be cached because of the totally stateless operation of the REST approach, this is perfect.
That covers a lot of solutions in the above three. So why would I even consider SOAP? Again, SOAP is fairly mature and well-defined and does come with a complete specification. The REST approach is just that, an approach and is wide open for development, so if you have the following then SOAP is a great solution:
  • Asynchronous processing and invocation; if your application needs a guaranteed level of reliability and security then SOAP 1.2 offers additional standards to ensure this type of operation. Things like WSRM – WS-Reliable Messaging.
  • Formal contracts; if both sides (provider and consumer) have to agree on the exchange format then SOAP 1.2 gives the rigid specifications for this type of interaction.
  • Stateful operations; if the application needs contextual information and conversational state management then SOAP 1.2 has the additional specification in the WS* structure to support those things (Security, Transactions, Coordination, etc). Comparatively, the REST approach would make the developers build this custom plumbing.
The content below is from another article which explains the pros and cons of REST APIs.
REST APIs provide a great deal of flexibility, which is one of their key advantages. Data is not tied to resources or methods, so REST can handle multiple types of calls, return different data formats and even change structurally with the correct implementation of hypermedia. This allows developers to build APIs that can meet their own needs while also meeting the needs of multiple types of customers.
The disadvantage to RESTful APIs is that you can lose the ability to maintain state in REST. They can also be more difficult for newer developers to use.

No comments:

Post a Comment