Using CORBA Request-Level Interceptors

RequestInterceptor::exception_occurred

Synopsis

Is called by the ORB to allow the interceptor to clean up any state that the interceptor might have been managing that is specific to a request.

C++ Binding

virtual void 
          exception_occurred( const ReplyContext & reply_context,
                              CORBA::Exception_ptr excep_val) = 0;

Parameters

reply_context

A reference to a ReplyContext that contains information about the context in which the reply is being performed.

excep_val

A pointer to the exception reported by the ORB or by another interceptor.

Exceptions

None.

Description

The exception_occurred operation is called on a request-level interceptor implementation in one of three cases:

Another interceptor sets an exception (rather than an exception being generated by the ORB or the method).

The ORB detects an operating system or communication-related problem.

A client deletes a Request object that was used to initiate a deferred synchronous DII. The exception_occurred method is called instead of the client_response or target_response method of that interceptor. The ORB calls the exception_occurred method to allow the interceptor implementation to clean up any state that it might have been managing that is specific to a request.

Return Values

None.

RequestLevelInterceptor::
ClientRequestInterceptor Interface

This is the base interface of all request-level interceptors. It inherits directly from the RequestLevelInterceptor::RequestInterceptor interface. The interface contains the set of operations and attributes that are supported by all client-side request-level interceptors.

Listing 8-5 OMG IDL Definition

//File: RequestLevelInterceptor.idl

#ifndef _REQUEST_LEVEL_INTERCEPTOR_IDL
#define _REQUEST_LEVEL_INTERCEPTOR_IDL

#include <orb.idl>
#include <Giop.idl>
#include <Interceptors.idl>

#pragma prefix "beasys.com"

module RequestLevelInterceptor
  {
  local ClientRequestInterceptor : RequestInterceptor
    {
    InvokeReturnStatus 
      client_invoke( 
             in    RequestContext           request_context,
             in    ServiceContextList       service_context,
             in    CORBA::DataInputStream   request_arg_stream,
             in    CORBA::DataOutputStream  reply_arg_stream,
             out   ExceptionValue           excep_val
                   );

    ResponseReturnStatus 
      client_response(
                    in    ReplyContext           reply_context,
                    in    ServiceContextList     service_context,
                    in    CORBA::DataInputStream arg_stream,
                    out   ExceptionValue         excep_val
                     );
    };
  };
#endif /* _REQUEST_LEVEL_INTERCEPTOR_IDL */

The implementation of the operations _duplicate, _narrow, and _nil are inherited indirectly from the implementation of the CORBA::LocalBase interface provided by the CORBA ORB in the BEA Tuxedo product.

Listing 8-6 C++ Declaration

#ifndef _RequestLevelInterceptor_h
#define _RequestLevelInterceptor_h

#include <CORBA.h>
#include <IOP.h>
#include <GIOP.h>
#include <Interceptors.h>

class OBBEXPDLL RequestLevelInterceptor
  {
  public:
    class   ClientRequestInterceptor;
    typedef ClientRequestInterceptor *  
               ClientRequestInterceptor_ptr;

    class OBBEXPDLL ClientRequestInterceptor : 
            public virtual  RequestInterceptor
      {
      public:
        static ClientRequestInterceptor_ptr 
          _duplicate(ClientRequestInterceptor_ptr obj);
        static ClientRequestInterceptor_ptr 
          _narrow(ClientRequestInterceptor_ptr obj);
        inline static ClientRequestInterceptor_ptr 
          _nil() { return 0; }

        virtual Interceptors::InvokeReturnStatus 
          client_invoke( 
              const RequestContext & request_context,
              ServiceContextList_ptr service_context,
              CORBA::DataInputStream_ptr request_arg_stream,
              CORBA::DataOutputStream_ptr reply_arg_stream,
              CORBA::Exception_ptr & excep_val ) = 0;

        virtual Interceptors::ResponseReturnStatus 
          client_response(
              const ReplyContext & reply_context,
              ServiceContextList_ptr service_context,
              CORBA::DataInputStream_ptr arg_stream,
              CORBA::Exception_ptr & excep_val ) = 0;

      protected:
        ClientRequestInterceptor(CORBA::LocalBase_ptr obj = 0) { }
        virtual ~ClientRequestInterceptor(){ }

      private:
        ClientRequestInterceptor( const ClientRequestInterceptor&) 
           { }
        void operator=(const ClientRequestInterceptor&) { }
      };  // class ClientRequestInterceptor
  };
#endif /* _RequestLevelInterceptor_h */