/*
* Copyright 2002-2017 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
*
* http://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.integration.aggregator;
import org.springframework.integration.store.MessageGroup;
import org.springframework.messaging.Message;
/**
* A {@link ReleaseStrategy} that releases all messages if any of the following is true:
*
* <ul>
* <li>The sequence is complete (if there is one).</li>
* <li>There are more messages than a threshold set by the user.</li>
* <li>The time elapsed since the earliest message, according to their timestamps, exceeds a timeout set by the user.</li>
* </ul>
*
* @author Dave Syer
*
* @since 2.0
*/
public class TimeoutCountSequenceSizeReleaseStrategy implements ReleaseStrategy {
/**
* Default timeout is one minute.
*/
public static final long DEFAULT_TIMEOUT = 60 * 1000;
/**
* Default threshold is effectively infinite.
*/
public static final int DEFAULT_THRESHOLD = Integer.MAX_VALUE;
private final int threshold;
private final long timeout;
public TimeoutCountSequenceSizeReleaseStrategy() {
this(DEFAULT_THRESHOLD, DEFAULT_TIMEOUT);
}
/**
* @param threshold the number of messages to accept before releasing
* @param timeout the timeout for the release in milliseconds
*/
public TimeoutCountSequenceSizeReleaseStrategy(int threshold, long timeout) {
this.threshold = threshold;
this.timeout = timeout;
}
public boolean canRelease(MessageGroup messages) {
long elapsedTime = System.currentTimeMillis() - findEarliestTimestamp(messages);
return messages.isComplete() || messages.getMessages().size() >= this.threshold || elapsedTime > this.timeout;
}
/**
* @param messages the message group
* @return the earliest timestamp or Long.MAX_VALUE
*/
private long findEarliestTimestamp(MessageGroup messages) {
long result = Long.MAX_VALUE;
for (Message<?> message : messages.getMessages()) {
long timestamp = message.getHeaders().getTimestamp();
if (timestamp < result) {
result = timestamp;
}
}
return result;
}
}