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.component.directvm; 018 019import org.apache.camel.AsyncCallback; 020import org.apache.camel.Exchange; 021import org.apache.camel.impl.DefaultAsyncProducer; 022import org.apache.camel.util.StopWatch; 023import org.slf4j.Logger; 024import org.slf4j.LoggerFactory; 025 026/** 027 * The direct producer. 028 * <p/> 029 * If blocking is enabled ({@code DirectEndpoint#isBlock}) then the 030 * DirectEndpoint will create an instance of this class instead of 031 * {@code DirectProducer}. This producers {@code process} method will block for 032 * the configured duration ({@code DirectEndpoint#getTimeout}, default to 30 033 * seconds). After which if a consumer is still unavailable a 034 * DirectConsumerNotAvailableException will be thrown. 035 * <p/> 036 * Implementation note: Concurrent Producers will block for the duration it 037 * takes to determine if a consumer is available, but actual consumer execution 038 * will happen concurrently. 039 */ 040public class DirectVmBlockingProducer extends DefaultAsyncProducer { 041 private static final Logger LOG = LoggerFactory.getLogger(DirectVmBlockingProducer.class); 042 private final DirectVmEndpoint endpoint; 043 044 public DirectVmBlockingProducer(DirectVmEndpoint endpoint) { 045 super(endpoint); 046 this.endpoint = endpoint; 047 } 048 049 public void process(Exchange exchange) throws Exception { 050 getConsumer(exchange).getProcessor().process(exchange); 051 } 052 053 public boolean process(Exchange exchange, AsyncCallback callback) { 054 try { 055 return getConsumer(exchange).getAsyncProcessor().process(exchange, callback); 056 } catch (Exception e) { 057 exchange.setException(e); 058 callback.done(true); 059 return true; 060 } 061 } 062 063 protected DirectVmConsumer getConsumer(Exchange exchange) throws Exception { 064 DirectVmConsumer answer = endpoint.getConsumer(); 065 if (answer == null) { 066 // okay then await until we have a consumer or we timed out 067 if (endpoint.isFailIfNoConsumers()) { 068 throw new DirectVmConsumerNotAvailableException("No consumers available on endpoint: " + endpoint, exchange); 069 } else { 070 answer = awaitConsumer(); 071 if (answer == null) { 072 throw new DirectVmConsumerNotAvailableException("No consumers available on endpoint: " + endpoint, exchange); 073 } 074 } 075 } 076 077 return answer; 078 } 079 080 private DirectVmConsumer awaitConsumer() throws InterruptedException { 081 DirectVmConsumer answer = null; 082 083 StopWatch watch = new StopWatch(); 084 boolean done = false; 085 while (!done) { 086 // sleep a bit to give chance for the consumer to be ready 087 Thread.sleep(500); 088 if (LOG.isDebugEnabled()) { 089 LOG.debug("Waited {} for consumer to be ready", watch.taken()); 090 } 091 092 answer = endpoint.getConsumer(); 093 if (answer != null) { 094 return answer; 095 } 096 // we are done if we hit the timeout 097 done = watch.taken() >= endpoint.getTimeout(); 098 } 099 return answer; 100 } 101 102}