Service details in case of Java REST web services

Question

I am new to web services in Java.

In SOAP web services, we have wsdl that tells us about the services like the operations etc. but in REST, we don't get wsdl .

So, my question is if someone wants to know the service details, then how that can be found in case of REST web services.

Answer 1

With REST there is no single established way to achieve this yet, however there are couple of options emerging:

• Swagger http://swagger.wordnik.com/ - Inspects annotations in your source code (supports web frameworks JAX-RS annotations, Spring annotatins, Play2) and generates a JSON document describing your APIs. This JSON document can be displayed as an interactive web page as end user documentation using swagger-ui .
• Json Home http://tools.ietf.org/html/draft-nottingham-json-home-02 - Specification for a JSON document that describes your RESTful APIs
• WADL http://en.wikipedia.org/wiki/Web_Application_Description_Language

Answer 2

SOAP introduced WSDL to describe services, which can automatically be discovered and integrated with a mechanisms like UDDI. In reality SOAP is used just as hardcoded RPCs. If you use REST, many details like exceptionhandling, operation types, idempotency are handled using well known HTTP mechanisms. The only thing you need to know is the payload encoding. If you use XML, you may use XSDs to describe the services, if you use JSON you need to handle this on your own (its a lot simpler). The structure of your URLs should be designed so its intuitive enough, to be described in a one paged readme file. To cut a long answer short: WebServices were so complicated you need a lot of boilerplating, REST services should be so simple, that a developr does not have to redefine and redocument the basics.