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 }