Preview of some of the changes to Apex REST in version 24.0

UpdatedApexREST.java

@RestResource(urlMapping='/FieldCase/*')
global class ApexRESTUpdate {
  
//Note we no longer need to include RestRequest and RestResponse as incoming parameters
//The static RestContext has request and response properties instead
  @HttpGet
  global static List<Case> getOpenCases() {
    String companyName = RestContext.request.params.get('companyName');
    Account company = [ Select ID, Name, BillingState from Account where Name = :companyName];
    List<Case> cases = [SELECT Id, Subject, Status, OwnerId, Owner.Name from Case WHERE AccountId =: company.Id];
    return cases;
    
  }

//Here we are using CaseSummary as an incoming parameter, which is an Apex class not an SObject.
//Previously, you could not use user defined params
  @HttpPost 
  global static String createCase(CaseSummary cs) {
		Case c = new Case();
		c.Subject = cs.CaseExternalID + cs.CaseDescription;
		insert c;
		
		return c.Subject;
	}
}