IMessageHandler (Azure SDK for Java Reference Documentation)

```
public interface IMessageHandler
```
Defines the contract for registering the callback QueueClient.registerMessageHandler(IMessageHandler) and SubscriptionClient.registerMessageHandler(IMessageHandler) for QueueClient and SubscriptionClient.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`notifyException(Throwable exception, ExceptionPhase phase)`	Receiving the exceptions that passed by pump during message processing.
`CompletableFuture<Void>`	`onMessageAsync(IMessage message)`	The callback for message pump to pass received `Message`s.

- Method Detail
  - onMessageAsync
```
CompletableFuture<Void> onMessageAsync(IMessage message)
```
    The callback for message pump to pass received Messages.
    
    Parameters:
    
    message - The received Message.
    
    Returns:
    
    CompletableFuture for the message handler.
  - notifyException
```
void notifyException(Throwable exception,
                     ExceptionPhase phase)
```
    Receiving the exceptions that passed by pump during message processing.
    
    Parameters:
    
    exception - Exception received in pump.
    
    phase - Exception phase.