001 /**
002 *
003 * Licensed to the Apache Software Foundation (ASF) under one or more
004 * contributor license agreements. See the NOTICE file distributed with
005 * this work for additional information regarding copyright ownership.
006 * The ASF licenses this file to You under the Apache License, Version 2.0
007 * (the "License"); you may not use this file except in compliance with
008 * the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018 package org.apache.camel.processor;
019
020 import org.apache.camel.Processor;
021 import org.apache.camel.Exchange;
022 import org.apache.camel.spi.Policy;
023 import org.apache.camel.impl.ServiceSupport;
024 import org.apache.camel.util.ServiceHelper;
025
026 /**
027 * A Delegate pattern which delegates processing to a nested processor which can be useful for implementation inheritence
028 * when writing an {@link Policy}
029 *
030 * @version $Revision: 519941 $
031 */
032 public class DelegateProcessor extends ServiceSupport implements Processor {
033 protected Processor next;
034
035 public DelegateProcessor() {
036 }
037
038 public DelegateProcessor(Processor next) {
039 this.next = next;
040 }
041
042 public void process(Exchange exchange) throws Exception {
043 processNext(exchange);
044 }
045
046 protected void processNext(Exchange exchange) throws Exception {
047 if (next != null) {
048 next.process(exchange);
049 }
050 }
051
052 @Override
053 public String toString() {
054 return "delegate(" + next + ")";
055 }
056
057 public Processor getNext() {
058 return next;
059 }
060
061 public void setNext(Processor next) {
062 this.next = next;
063 }
064
065 protected void doStart() throws Exception {
066 ServiceHelper.startServices(next);
067 }
068
069 protected void doStop() throws Exception {
070 ServiceHelper.stopServices(next);
071 }
072 }