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 public DirectEndpoint getEndpoint() { 042 return (DirectEndpoint) super.getEndpoint(); 043 } 044 045 @Override 046 protected void doStart() throws Exception { 047 // add consumer to endpoint 048 boolean existing = this == endpoint.getConsumer(); 049 if (!existing && endpoint.hasConsumer(this)) { 050 throw new IllegalArgumentException("Cannot add a 2nd consumer to the same endpoint. Endpoint " + endpoint + " only allows one consumer."); 051 } 052 if (!existing) { 053 endpoint.addConsumer(this); 054 } 055 } 056 057 @Override 058 protected void doStop() throws Exception { 059 endpoint.removeConsumer(this); 060 } 061 062 @Override 063 protected void doSuspend() throws Exception { 064 endpoint.removeConsumer(this); 065 } 066 067 @Override 068 protected void doResume() throws Exception { 069 // resume by using the start logic 070 doStart(); 071 } 072 073 public boolean deferShutdown(ShutdownRunningTask shutdownRunningTask) { 074 // deny stopping on shutdown as we want direct consumers to run in case some other queues 075 // depend on this consumer to run, so it can complete its exchanges 076 return true; 077 } 078 079 public int getPendingExchangesSize() { 080 // return 0 as we do not have an internal memory queue with a variable size 081 // of inflight messages. 082 return 0; 083 } 084 085 public void prepareShutdown(boolean forced) { 086 // noop 087 } 088 }