org.springframework.amqp.rabbit.retry.NewMessageIdentifier Maven / Gradle / Ivy
/*
* Copyright 2002-2019 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.amqp.rabbit.retry;
import org.springframework.amqp.core.Message;
/**
* An optimization for stateful retry of message processing. If a message is known to be "new", i.e. never consumed
* before by this or any other client, then there are potential optimizations for managing the state associated with
* tracking the processing of a message (e.g. there is no need to check a cache for a hit).
*
* @author Dave Syer
* @author Gary Russell
*
*/
@FunctionalInterface
public interface NewMessageIdentifier {
/**
* Query a message to see if it has been seen before. Usually it is only possible to know if it has definitely not
* been seen before (e.g. through the redelivered flag, which would be used by default). Clients can customize the
* retry behaviour for failed messages by implementing this method.
*
* @param message the message to test
* @return true if the message is known to not have been consumed before
*/
boolean isNew(Message message);
}