This version is still in development and is not considered stable yet. For the latest stable version, please use Spring AMQP 3.2.1! |
Handling Exceptions
By default, if an annotated listener method throws an exception, it is thrown to the container and the message are requeued and redelivered, discarded, or routed to a dead letter exchange, depending on the container and broker configuration. Nothing is returned to the sender.
Starting with version 2.0, the @RabbitListener
annotation has two new attributes: errorHandler
and returnExceptions
.
These are not configured by default.
You can use the errorHandler
to provide the bean name of a RabbitListenerErrorHandler
implementation.
This functional interface has one method, as follows:
@FunctionalInterface
public interface RabbitListenerErrorHandler {
Object handleError(Message amqpMessage, org.springframework.messaging.Message<?> message,
ListenerExecutionFailedException exception) throws Exception;
}
As you can see, you have access to the raw message received from the container, the spring-messaging Message<?>
object produced by the message converter, and the exception that was thrown by the listener (wrapped in a ListenerExecutionFailedException
).
The error handler can either return some result (which is sent as the reply) or throw the original or a new exception (which is thrown to the container or returned to the sender, depending on the returnExceptions
setting).
The returnExceptions
attribute, when true
, causes exceptions to be returned to the sender.
The exception is wrapped in a RemoteInvocationResult
object.
On the sender side, there is an available RemoteInvocationAwareMessageConverterAdapter
, which, if configured into the RabbitTemplate
, re-throws the server-side exception, wrapped in an AmqpRemoteException
.
The stack trace of the server exception is synthesized by merging the server and client stack traces.
This mechanism generally works only with the default SimpleMessageConverter , which uses Java serialization.
Exceptions are generally not “Jackson-friendly” and cannot be serialized to JSON.
If you use JSON, consider using an errorHandler to return some other Jackson-friendly Error object when an exception is thrown.
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In version 2.1, this interface moved from package o.s.amqp.rabbit.listener to o.s.amqp.rabbit.listener.api .
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Starting with version 2.1.7, the Channel
is available in a messaging message header; this allows you to ack or nack the failed message when using AcknowledgeMode.MANUAL
:
public Object handleError(Message amqpMessage, org.springframework.messaging.Message<?> message,
ListenerExecutionFailedException exception) {
...
message.getHeaders().get(AmqpHeaders.CHANNEL, Channel.class)
.basicReject(message.getHeaders().get(AmqpHeaders.DELIVERY_TAG, Long.class),
true);
}
Starting with version 2.2.18, if a message conversion exception is thrown, the error handler will be called, with null
in the message
argument.
This allows the application to send some result to the caller, indicating that a badly-formed message was received.
Previously, such errors were thrown and handled by the container.