The REST based approach for communicating between Legacy systems and middleware layer.. Part 1
People generally tend to overlook old approaches, but these same approaches, in the past, have emerged as compelling technologies. This very same mindset has also been applied to the REST approach. The idea may be old but when realized, it becomes a technology that uses existing protocols of web to build robust web services.
It is not a set of tools but rather an architectural style in which the Web already works. When we re-construct what we already know about web and frame it into a set of principles, then what we get is the REST approach.
It is not a set of tools but rather an architectural style in which the Web already works. When we re-construct what we already know about web and frame it into a set of principles, then what we get is the REST approach.
In Service Oriented Architecture (SOA), we all are familiar with interacting with end applications by sending Simple Object Access Protocol (SOAP) messages. But, there are other systems such as the legacy systems that could be interested in communicating with the middle ware layer using HTTP requests rather than SOAP requests. In such a scenario, the end systems would not provide us with Web service Interface (WSDL) to invoke them, but would give the middle ware layer, HTTP URLs, on which they expect us to post xml messages. This process of communicating with external systems using HTTP requests rather than SOAP messages is REST BASED APPROACH for invoking services.
REST uses the existing web interfaces - GET, POST, PUT and DELETE - to communicate between web services. Unlike SOAP, there is no need for a new message format; REST uses simple XML for message communication.
REST is Representational State Transfer. In REST, every web service is treated as a Resource and can be identified by a URI/URL. In order to modify these resources, their representations are used. So, the next set of questions that arise are:
Q: What is a Representation of a web service?
A: The answer is the web page that a client requests for.
Q: What is State?
A: It is the application state or a session state.
Q: What is Transfer of state?
A: We can maintain an application/session state by transferring it from client to server and again back to client.
And with this, we come to the end of my brief introduction to the REST based approach. Stay tuned for my next blog on how REST works and what are its benefits!
REST uses the existing web interfaces - GET, POST, PUT and DELETE - to communicate between web services. Unlike SOAP, there is no need for a new message format; REST uses simple XML for message communication.
REST is Representational State Transfer. In REST, every web service is treated as a Resource and can be identified by a URI/URL. In order to modify these resources, their representations are used. So, the next set of questions that arise are:
Q: What is a Representation of a web service?
A: The answer is the web page that a client requests for.
Q: What is State?
A: It is the application state or a session state.
Q: What is Transfer of state?
A: We can maintain an application/session state by transferring it from client to server and again back to client.
And with this, we come to the end of my brief introduction to the REST based approach. Stay tuned for my next blog on how REST works and what are its benefits!
Do feel free to send in your comments..
