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.loadbalancer; 018 019import java.util.ArrayList; 020import java.util.List; 021import java.util.concurrent.CopyOnWriteArrayList; 022 023import org.apache.camel.Exchange; 024import org.apache.camel.Navigate; 025import org.apache.camel.Processor; 026import org.apache.camel.spi.IdAware; 027import org.apache.camel.support.ServiceSupport; 028import org.apache.camel.util.AsyncProcessorHelper; 029import org.apache.camel.util.ServiceHelper; 030import org.slf4j.Logger; 031import org.slf4j.LoggerFactory; 032 033/** 034 * A default base class for a {@link LoadBalancer} implementation. 035 * <p/> 036 * This implementation is dedicated for asynchronous load balancers. 037 * <p/> 038 * Consider using the {@link SimpleLoadBalancerSupport} if your load balancer does not by nature 039 * support asynchronous routing. 040 * 041 * @version 042 */ 043public abstract class LoadBalancerSupport extends ServiceSupport implements LoadBalancer, Navigate<Processor>, IdAware { 044 045 protected final Logger log = LoggerFactory.getLogger(getClass()); 046 private final List<Processor> processors = new CopyOnWriteArrayList<>(); 047 private String id; 048 049 public void addProcessor(Processor processor) { 050 processors.add(processor); 051 } 052 053 public void removeProcessor(Processor processor) { 054 processors.remove(processor); 055 } 056 057 public List<Processor> getProcessors() { 058 return processors; 059 } 060 061 public List<Processor> next() { 062 if (!hasNext()) { 063 return null; 064 } 065 return new ArrayList<>(processors); 066 } 067 068 public boolean hasNext() { 069 return processors.size() > 0; 070 } 071 072 public String getId() { 073 return id; 074 } 075 076 public void setId(String id) { 077 this.id = id; 078 } 079 080 protected void doStart() throws Exception { 081 ServiceHelper.startServices(processors); 082 } 083 084 protected void doStop() throws Exception { 085 ServiceHelper.stopServices(processors); 086 } 087 088 @Override 089 protected void doShutdown() throws Exception { 090 ServiceHelper.stopAndShutdownServices(processors); 091 for (Processor processor : processors) { 092 removeProcessor(processor); 093 } 094 } 095 096 public void process(Exchange exchange) throws Exception { 097 AsyncProcessorHelper.process(this, exchange); 098 } 099}