/*
* Copyright 2002-2008 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 java.util.Comparator;
import org.springframework.integration.IntegrationMessageHeaderAccessor;
import org.springframework.messaging.Message;
/**
* A {@link Comparator} implementation based on the 'sequence number'
* property of a {@link Message Message's} header.
*
* @author Mark Fisher
*/
public class MessageSequenceComparator implements Comparator<Message<?>> {
public int compare(Message<?> message1, Message<?> message2) {
Integer s1 = new IntegrationMessageHeaderAccessor(message1).getSequenceNumber();
Integer s2 = new IntegrationMessageHeaderAccessor(message2).getSequenceNumber();
if (s1 == null) {
s1 = 0;
}
if (s2 == null) {
s2 = 0;
}
return s1.compareTo(s2);
}
}