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.impl; 018 019import java.util.concurrent.ScheduledExecutorService; 020 021import org.apache.camel.Endpoint; 022import org.apache.camel.Exchange; 023import org.apache.camel.PollingConsumer; 024import org.apache.camel.Processor; 025import org.apache.camel.util.ServiceHelper; 026 027/** 028 * A default implementation of an event driven {@link org.apache.camel.Consumer} which uses the 029 * {@link PollingConsumer} 030 * 031 * @version 032 */ 033public class DefaultScheduledPollConsumer extends ScheduledPollConsumer { 034 private PollingConsumer pollingConsumer; 035 private int timeout; 036 037 public DefaultScheduledPollConsumer(DefaultEndpoint defaultEndpoint, Processor processor) { 038 super(defaultEndpoint, processor); 039 } 040 041 public DefaultScheduledPollConsumer(Endpoint endpoint, Processor processor, ScheduledExecutorService executor) { 042 super(endpoint, processor, executor); 043 } 044 045 protected int poll() throws Exception { 046 int messagesPolled = 0; 047 048 while (isPollAllowed()) { 049 Exchange exchange; 050 if (timeout == 0) { 051 exchange = pollingConsumer.receiveNoWait(); 052 } else if (timeout < 0) { 053 exchange = pollingConsumer.receive(); 054 } else { 055 exchange = pollingConsumer.receive(timeout); 056 } 057 058 if (exchange == null) { 059 break; 060 } 061 062 messagesPolled++; 063 log.trace("Polled {} {}", messagesPolled, exchange); 064 065 // if the result of the polled exchange has output we should create a new exchange and 066 // use the output as input to the next processor 067 if (exchange.hasOut()) { 068 // lets create a new exchange 069 Exchange newExchange = getEndpoint().createExchange(); 070 newExchange.getIn().copyFrom(exchange.getOut()); 071 exchange = newExchange; 072 } 073 getProcessor().process(exchange); 074 } 075 076 return messagesPolled; 077 } 078 079 public int getTimeout() { 080 return timeout; 081 } 082 083 /** 084 * Sets a timeout to use with {@link PollingConsumer}. 085 * <br/> 086 * <br/>Use <tt>timeout < 0</tt> for {@link PollingConsumer#receive()}. 087 * <br/>Use <tt>timeout == 0</tt> for {@link PollingConsumer#receiveNoWait()}. 088 * <br/>Use <tt>timeout > 0</tt> for {@link PollingConsumer#receive(long)}}. 089 * <br/> The default timeout value is <tt>0</tt> 090 * 091 * @param timeout the timeout value 092 */ 093 public void setTimeout(int timeout) { 094 this.timeout = timeout; 095 } 096 097 @Override 098 protected void doStart() throws Exception { 099 pollingConsumer = getEndpoint().createPollingConsumer(); 100 ServiceHelper.startService(pollingConsumer); 101 super.doStart(); 102 } 103 104 @Override 105 protected void doStop() throws Exception { 106 ServiceHelper.stopService(pollingConsumer); 107 super.doStop(); 108 } 109}