Raw SOAP XML response

Hello

I need to save the raw SOAP XML response from Axis2(I use axis 2 1.7.3).
When Axis2 call retusrns an error this code works: String response = 
sc.getLastOperationContext().getMessageContext("In").getEnvelope().toString();
But when I run a succesful Axis2 call the same code gives the following 
error: "java.lang.IllegalStateException: Can't process next node because 
caching is disabled"

I tryed to enable cache like this, but it didn't work:

                                 ServiceClient sc = 
(ServiceClient)method_getServiceClient.invoke(objectReflect);
                                 ServiceContext srv_context = 
sc.getServiceContext();
                                 
srv_context.setCachingOperationContext(true);
                                 OperationContext oc= new 
OperationContext();
                                 oc.setComplete(true);
                                 srv_context.setLastOperationContext(oc);

Thank you