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 */ 017package org.apache.camel.processor; 018 019import java.util.ArrayList; 020import java.util.List; 021 022import org.apache.camel.Exchange; 023import org.apache.camel.Navigate; 024import org.apache.camel.Processor; 025import org.apache.camel.support.ServiceSupport; 026import org.apache.camel.util.ServiceHelper; 027 028/** 029 * A Delegate pattern which delegates processing to a nested {@link Processor} which can 030 * be useful for implementation inheritance when writing an {@link org.apache.camel.spi.Policy} 031 * <p/> 032 * <b>Important:</b> This implementation does <b>not</b> support the asynchronous routing engine. 033 * If you are implementing a EIP pattern please use the {@link org.apache.camel.processor.DelegateAsyncProcessor} 034 * instead. 035 * 036 * @version 037 * @see org.apache.camel.processor.DelegateAsyncProcessor 038 */ 039public class DelegateProcessor extends ServiceSupport implements org.apache.camel.DelegateProcessor, Processor, Navigate<Processor> { 040 protected Processor processor; 041 042 public DelegateProcessor() { 043 } 044 045 public DelegateProcessor(Processor processor) { 046 if (processor == this) { 047 throw new IllegalArgumentException("Recursive DelegateProcessor!"); 048 } 049 this.processor = processor; 050 } 051 052 public void process(Exchange exchange) throws Exception { 053 processNext(exchange); 054 } 055 056 protected void processNext(Exchange exchange) throws Exception { 057 if (processor != null) { 058 processor.process(exchange); 059 } 060 } 061 062 @Override 063 public String toString() { 064 return "Delegate[" + processor + "]"; 065 } 066 067 public Processor getProcessor() { 068 return processor; 069 } 070 071 public void setProcessor(Processor processor) { 072 this.processor = processor; 073 } 074 075 protected void doStart() throws Exception { 076 ServiceHelper.startServices(processor); 077 } 078 079 protected void doStop() throws Exception { 080 ServiceHelper.stopServices(processor); 081 } 082 083 public boolean hasNext() { 084 return processor != null; 085 } 086 087 public List<Processor> next() { 088 if (!hasNext()) { 089 return null; 090 } 091 List<Processor> answer = new ArrayList<>(1); 092 answer.add(processor); 093 return answer; 094 } 095}