001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.camel.processor;
018
019 import java.util.Comparator;
020 import java.util.List;
021 import java.util.Set;
022 import java.util.TreeSet;
023
024 import org.apache.camel.Exchange;
025 import org.apache.camel.Expression;
026 import org.apache.camel.Processor;
027 import org.apache.camel.util.ExpressionComparator;
028 import org.apache.camel.util.ExpressionListComparator;
029
030 /**
031 * An implementation of the <a href="http://camel.apache.org/resequencer.html">Resequencer</a>
032 * which can reorder messages within a batch.
033 *
034 * @version $Revision: 738604 $
035 */
036 public class Resequencer extends BatchProcessor {
037 public Resequencer(Processor processor, Expression expression) {
038 this(processor, createSet(expression));
039 }
040
041 public Resequencer(Processor processor, List<Expression> expressions) {
042 this(processor, createSet(expressions));
043 }
044
045 public Resequencer(Processor processor, Set<Exchange> collection) {
046 super(processor, collection);
047 }
048
049 @Override
050 public String toString() {
051 return "Resequencer[to: " + getProcessor() + "]";
052 }
053
054 // Implementation methods
055 //-------------------------------------------------------------------------
056
057 protected static Set<Exchange> createSet(Expression expression) {
058 return createSet(new ExpressionComparator(expression));
059 }
060
061 protected static Set<Exchange> createSet(List<Expression> expressions) {
062 if (expressions.size() == 1) {
063 return createSet(expressions.get(0));
064 }
065 return createSet(new ExpressionListComparator(expressions));
066 }
067
068 protected static Set<Exchange> createSet(Comparator<? super Exchange> comparator) {
069 return new TreeSet<Exchange>(comparator);
070 }
071 }