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.spi; 018 019import org.apache.camel.CamelContextAware; 020import org.apache.camel.Consumer; 021import org.apache.camel.ShutdownableService; 022 023/** 024 * A pluggable scheduler for {@link org.apache.camel.impl.ScheduledPollConsumer} consumers. 025 * <p/> 026 * The default implementation {@link org.apache.camel.impl.DefaultScheduledPollConsumerScheduler} is 027 * using the {@link java.util.concurrent.ScheduledExecutorService} from the JDK to schedule and run the poll task. 028 * <p/> 029 * An alternative implementation is in <tt>camel-quartz2</tt> component that allows to use CRON expression 030 * to define when the scheduler should run. 031 */ 032public interface ScheduledPollConsumerScheduler extends ShutdownableService, CamelContextAware { 033 034 /** 035 * Initializes this {@link ScheduledPollConsumerScheduler} with the associated {@link Consumer}. 036 * 037 * @param consumer the consumer. 038 */ 039 void onInit(Consumer consumer); 040 041 /** 042 * Schedules the task to run. 043 * 044 * @param task the task to run. 045 */ 046 void scheduleTask(Runnable task); 047 048 /** 049 * Attempts to unschedules the last task which was scheduled. 050 * <p/> 051 * An implementation may not implement this method. 052 */ 053 void unscheduleTask(); 054 055 /** 056 * Starts the scheduler. 057 * <p/> 058 * If the scheduler is already started, then this is a noop method call. 059 */ 060 void startScheduler(); 061 062 /** 063 * Whether the scheduler has been started. 064 * 065 * @return <tt>true</tt> if started, <tt>false</tt> otherwise. 066 */ 067 boolean isSchedulerStarted(); 068 069}