why client cannot catch user-defined exception in AMI mode?

Comments

• marc FloridaAdministrators, ZeroC Staff Marc LaukienOrganization: ZeroC, Inc.Project: The Internet Communications Engine ZeroC Staff

  June 2007

  All exceptions are derived from Ice::Exception, including your own user exceptions. In your implementation of ice_exception(), you can down-cast the exception to your derived type to both check whether the exception that is raised is indeed your user exception, as well as to get the actual value of your exception. An alternative implementation is to re-throw the exception in ice_exception() with ex->ice_throw(), and then to use a catch() for your user exception.

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• marc FloridaAdministrators, ZeroC Staff Marc LaukienOrganization: ZeroC, Inc.Project: The Internet Communications Engine ZeroC Staff

  June 2007

  By the way, Ice 2.1.0 is quite old. I highly recommend to upgrade.

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• AaronIct Member wang yangOrganization: ICTProject: DBroker ✭

  June 2007

  ice_throw does not work
  

  marc wrote: »

  All exceptions are derived from Ice::Exception, including your own user exceptions. In your implementation of ice_exception(), you can down-cast the exception to your derived type to both check whether the exception that is raised is indeed your user exception, as well as to get the actual value of your exception. An alternative implementation is to re-throw the exception in ice_exception() with ex->ice_throw(), and then to use a catch() for your user exception.

  
  I re-throw the exception with ex->ice_throw.
  
  try{
  ex->ice_throw();
  }
  catch(myEx e)
  {
  //go to bed
  }
  catch(::Ice::Exception e)
  {
  //watch TV
  }
  
  I have never gone to bed ....
  
  can you give a sample code ?

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• benoit Rennes, FranceAdministrators, ZeroC Staff Benoit FoucherOrganization: ZeroC, Inc.Project: Ice ZeroC Staff

  June 2007

  Hi,
  
  This should work. Try for example to modify the client from the demo/Ice/async demo (available in Ice 3.2.0). Change the implementation of the AMI callback ice_exception method to:
  

      virtual void ice_exception(const Ice::Exception& ex)
      {
          try
          {
              ex.ice_throw();
          }
          catch(const RequestCanceledException&)
          {
              cerr << "request failed!" << endl;
          }
          catch(const Ice::Exception& ex)
          {
              cerr << "sayHello AMI call failed:\n" << ex << endl;
          }
      }
  

  
  Then run the client against the server and type "d" followed by "s" to shutdown server and get it to cancel the delayed request. You'll see that the exception is correctly catch by the client and the client will display "request failed!".
  
  Also, note that you should catch exceptions by reference not value, so your code should look like the following:

  try{
  ex.ice_throw();
  }
  catch(const myEx& e)
  {
  //go to bed
  }
  catch(const ::Ice::Exception& e)
  {
  //watch TV
  }
  

  
  Cheers,
  Benoit.

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