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