Grails - Domain classes as REST resources

Description

You can create a RESTful API in Grails, the simple way to do this is by using a domain class as a REST resource. You should add grails.rest.Resource transformation to domain class as shown below snippet−

OrderDemo.groovy

import grails.rest.*

@Resource(uri='/api/orders', formats=['json', 'xml'])
class Orderdemo {
   Long id
   String stock
   String side
   Double price
   Long size

   static mapping = {
      version false
      table 'orders'
      id column: 'id', generator:'native', params:[sequence:'order_seq']
   }

   static constraints = {
      stock blank:false
      price blank:false
      quantity blank:false
   }
}

Your domain class will be available as a REST resource in either XML or JSON formats, by just adding the Resource transformation and specifying a URI. Registering the required RESTful URL mapping and creating a controller called OrderdemoController will be done with the help of transformation.

If you want to test, you can add sample data in BootStrap.groovy file as shown below−

BootStrap.groovy

import grails.rest.example.Orderdemo

class BootStrap {
   def init = { servletContext ->
      new Orderdemo(stock:"Nokia", price:20000, quantity:100).save()
      new Orderdemo(stock:"Samsung", price:30000, quantity:200).save()
	  new Orderdemo(stock:"HTC", price:15000, quantity:300).save()
   }
   def destroy = {
   }
}

The JSON response can be obtained by using the ACCEPT header or by using the file extension in the URI. The table below shows to obtain JSON response using the Unix curl tool−

curl -i -H "Accept: application/json" localhost:8080/api/orders

curl -i -X POST -H "Content-Type: application/json" -d 
'{"price": 200,"side": "S","size": 5000,"stock": "TWT"}' localhost:8080/api/orders

curl -i -X PUT -H "Content-Type: application/json" -d
'{"price": 210,"size": 500}' localhost:8080/api/orders/1

curl -i -X DELETE localhost:8080/api/orders/1