Set an Exception Listener

All the APIs support the ability to set an exception listener on the connection that gets invoked when a connection breaks or experiences a fault-tolerant failover.

When the event is a disconnect, the exception handler can call various EMS methods without any problem. However, when the event is a fault-tolerant failover, the exception handler is not allowed to call any EMS method. To do so risks a deadlock. You can call the setExceptionOnFTSwitch method to receive an exception that contains the new server URL after a fault-tolerant failover has occurred.

The following examples demonstrate how to establish an exception listener for a connection.

• Java

  Implement an ExceptionListener.onException method, use the Connection object’s setExceptionListener method to register the exception listener, and call Tibjms.setExceptionOnFTSwitch to call the exception handler after a fault-tolerant failover:

  public class tibjmsMsgConsumer            
     implements ExceptionListener  
  {
  .....  
  public void onException(JMSException e)       
       {         
         /* Handle exception */       
       }
  .....  
  connection.setExceptionListener(this);  
  com.tibco.tibjms.Tibjms.setExceptionOnFTSwitch(true);
  .....  
  }

  See the tibjmsMsgConsumer.java sample client for a working example (without the setExceptionOnFTSwitch call).

• C

  Define an onException function to handle exceptions,
  use the tibemsConnection_SetExceptionListener function to call onException when an error is encountered, and call tibems_setExceptionOnFTSwitch to call the exception handler after a fault-tolerant failover:

  void onException(    
    tibemsConnection    conn,    
    tibems_status       reason,    
    void*               closure)  
   {     
     /* Handle exception */  
   }
   .....  
  status = tibemsConnection_SetExceptionListener(                                            
  					connection,                                            
  					onException,                                             
  					NULL);  
  tibems_setExceptionOnFTSwitch(TIBEMS_TRUE); 

  See the tibemsMsgConsumer.c sample client for a working example (without the setExceptionOnFTSwitch call).

• C#

  Implement an IExceptionListener.OnException method, set the Connection object’s ExceptionListener property to register the exception listener, and call Tibems.SetExceptionOnFTSwitch to call the exception handler after a fault-tolerant failover:

    public class csMsgConsumer : IExceptionListener  
    { 
  .....  
    public void OnException(EMSException e)       
        { 
       /* Handle exception */  
        } 
  .....  
    connection.ExceptionListener = this;  
    TIBCO.EMS.Tibems.SetExceptionOnFTSwitch(true);
  .....  
    }

  See the csMsgConsumer.cs sample client for a working example (without the setExceptionOnFTSwitch call).