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 org.apache.camel.Exchange; 020 import org.apache.camel.Processor; 021 import org.apache.camel.impl.ServiceSupport; 022 import org.apache.camel.util.ServiceHelper; 023 024 /** 025 * A Delegate pattern which delegates processing to a nested processor which can 026 * be useful for implementation inheritance when writing an {@link org.apache.camel.spi.Policy} 027 * 028 * @version $Revision: 751221 $ 029 */ 030 public class DelegateProcessor extends ServiceSupport implements Processor { 031 protected Processor processor; 032 033 public DelegateProcessor() { 034 } 035 036 public DelegateProcessor(Processor processor) { 037 if (processor == this) { 038 throw new IllegalArgumentException("Recursive DelegateProcessor!"); 039 } 040 this.processor = processor; 041 } 042 043 public void process(Exchange exchange) throws Exception { 044 processNext(exchange); 045 } 046 047 protected void processNext(Exchange exchange) throws Exception { 048 if (processor != null) { 049 processor.process(exchange); 050 } 051 } 052 053 @Override 054 public String toString() { 055 return "Delegate(" + processor + ")"; 056 } 057 058 public Processor getProcessor() { 059 return processor; 060 } 061 062 public void setProcessor(Processor processor) { 063 this.processor = processor; 064 } 065 066 protected void doStart() throws Exception { 067 ServiceHelper.startServices(processor); 068 } 069 070 protected void doStop() throws Exception { 071 ServiceHelper.stopServices(processor); 072 } 073 074 /** 075 * Proceed with the underlying delegated processor 076 */ 077 public void proceed(Exchange exchange) throws Exception { 078 processNext(exchange); 079 } 080 }