| /** |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.activemq.thread; |
| |
| import java.util.HashMap; |
| import java.util.Timer; |
| import java.util.TimerTask; |
| import org.apache.activemq.util.ServiceStopper; |
| import org.apache.activemq.util.ServiceSupport; |
| |
| /** |
| * |
| */ |
| public final class Scheduler extends ServiceSupport { |
| private final String name; |
| private Timer timer; |
| private final HashMap<Runnable, TimerTask> timerTasks = new HashMap<Runnable, TimerTask>(); |
| |
| public Scheduler (String name) { |
| this.name = name; |
| } |
| |
| public void executePeriodically(final Runnable task, long period) { |
| TimerTask timerTask = new SchedulerTimerTask(task); |
| timer.scheduleAtFixedRate(timerTask, period, period); |
| timerTasks.put(task, timerTask); |
| } |
| |
| /* |
| * execute on rough schedual based on termination of last execution. There is no |
| * compensation (two runs in quick succession) for delays |
| */ |
| public synchronized void schedualPeriodically(final Runnable task, long period) { |
| TimerTask timerTask = new SchedulerTimerTask(task); |
| timer.schedule(timerTask, period, period); |
| timerTasks.put(task, timerTask); |
| } |
| |
| public synchronized void cancel(Runnable task) { |
| TimerTask ticket = timerTasks.remove(task); |
| if (ticket != null) { |
| ticket.cancel(); |
| timer.purge();//remove cancelled TimerTasks |
| } |
| } |
| |
| public synchronized void executeAfterDelay(final Runnable task, long redeliveryDelay) { |
| TimerTask timerTask = new SchedulerTimerTask(task); |
| timer.schedule(timerTask, redeliveryDelay); |
| } |
| |
| public void shutdown() { |
| timer.cancel(); |
| } |
| |
| @Override |
| protected synchronized void doStart() throws Exception { |
| this.timer = new Timer(name, true); |
| |
| } |
| |
| @Override |
| protected synchronized void doStop(ServiceStopper stopper) throws Exception { |
| if (this.timer != null) { |
| this.timer.cancel(); |
| } |
| |
| } |
| } |