log4p

Since working with, or creating WebServices is something webdevelopers will probably do regularly (or stumble upon in the very near future) I decided to have a look at Grails' support for SOAP.

First thing I wanted to see was how to expose a Grails service via Soap. Due to the excellent documentation at the Grails website this proved to be really simple:

Setup

1. download the XFire plugin here
2. install the plugin by running "grails install-plugin /path/to/grails-XFire-x.x.x.zip" from the root of your project

Create a service

1. run "grails create-service Task" from the root of your project
2. Implement it and configure it for XFire remoting:
   PLAIN TEXT
   GROOVY:

   1. class TaskService {
   2.     static expose=['xfire'] // expose remotely using xfire
   3.    
   4.     boolean transactional = true
   5.    
   6.     def String[] findTasksBySubject(String s) {
   7.         def c = Task.createCriteria()
   8.         def results = c{
   9.             like("subject", "%${s}%")
   10.         }
   11.  
   12.         return results*.subject
   13.     }
   14. }
   • Notice the *. (spread-dot) operator? It collects results from call the consequent method on each item in the list, cool!
   • Notice the Hibernate Criteria Builder, more info here
   • Notice the 'transactional' propery, setting it to true results in all methods of a service are wrapped in a transaction.
3. Start your application, and point your browser to: http://localhost:8080/ptodo/services/task?wsdl
   which gives you the WSDL describing your service!
4. done!

Of course there is no point in having a WebService without a client... which is only 3 lines of Groovy away. From your favorite Groovy shell, run (after installing the SOAP libs):

Almost instant gratification!