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 */ 017 package org.apache.camel.component.direct; 018 019 import org.apache.camel.Endpoint; 020 import org.apache.camel.Processor; 021 import org.apache.camel.ShutdownRunningTask; 022 import org.apache.camel.SuspendableService; 023 import org.apache.camel.impl.DefaultConsumer; 024 import org.apache.camel.spi.ShutdownAware; 025 026 /** 027 * The direct consumer. 028 * 029 * @version 030 */ 031 public class DirectConsumer extends DefaultConsumer implements ShutdownAware, SuspendableService { 032 033 private DirectEndpoint endpoint; 034 035 public DirectConsumer(Endpoint endpoint, Processor processor) { 036 super(endpoint, processor); 037 this.endpoint = (DirectEndpoint) endpoint; 038 } 039 040 @Override 041 protected void doStart() throws Exception { 042 // add consumer to endpoint 043 boolean existing = this == endpoint.getConsumer(); 044 if (!existing && endpoint.hasConsumer(this)) { 045 throw new IllegalArgumentException("Cannot add a 2nd consumer to the same endpoint. Endpoint " + endpoint + " only allows one consumer."); 046 } 047 if (!existing) { 048 endpoint.addConsumer(this); 049 } 050 } 051 052 @Override 053 protected void doStop() throws Exception { 054 endpoint.removeConsumer(this); 055 } 056 057 @Override 058 protected void doSuspend() throws Exception { 059 endpoint.removeConsumer(this); 060 } 061 062 @Override 063 protected void doResume() throws Exception { 064 // resume by using the start logic 065 doStart(); 066 } 067 068 public boolean deferShutdown(ShutdownRunningTask shutdownRunningTask) { 069 // deny stopping on shutdown as we want direct consumers to run in case some other queues 070 // depend on this consumer to run, so it can complete its exchanges 071 return true; 072 } 073 074 public int getPendingExchangesSize() { 075 // return 0 as we do not have an internal memory queue with a variable size 076 // of inflight messages. 077 return 0; 078 } 079 080 public void prepareShutdown(boolean forced) { 081 // noop 082 } 083 }