REST in Grails

How it works

Groovy includes some built-in support for XML, such as the XMLSlurper. Grails also includes converters for simply converting objects to XML or JSON or vice versa.

import grails.converters.JSON
import grails.converters.XML

class BookController {
   def getBooks = {
     render Book.list() as JSON
   }
   def getBooksXML = {
     render Book.list() as XML
   }
}

For REST services that service multiple formats, you can use the built-in withFormat in Grails. So the above would become the following:

def getBooks = {
     withFormat {
        json { render list as JSON }
        xml { render list as XML }
     }
}

Then Grails would decide which format to use based on numerous inputs; the simplest being the extension of the URL, such as .json or the request’s Accept header.

For using web-services in Grails, there’s a rest plugin available.