| /* |
| * 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.servicemix.components.util; |
| |
| import java.util.Date; |
| |
| import javax.jbi.JBIException; |
| import javax.resource.spi.work.Work; |
| |
| import org.apache.servicemix.components.varscheduler.ScheduleIterator; |
| import org.apache.servicemix.components.varscheduler.Scheduler; |
| import org.apache.servicemix.components.varscheduler.SchedulerTask; |
| import org.apache.servicemix.executors.Executor; |
| import org.apache.servicemix.executors.ExecutorFactory; |
| import org.apache.servicemix.jbi.framework.ComponentContextImpl; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * An implementation inheritence class for a component which polls some resource |
| * at periodic intervals to decide if there is an event to process. |
| * |
| * @version $Revision$ |
| */ |
| public abstract class PollingComponentSupport extends ComponentSupport implements Work { |
| |
| private static final Logger LOGGER = LoggerFactory.getLogger(PollingComponentSupport.class); |
| |
| private Executor executor; |
| private Scheduler scheduler; |
| private Date firstTime; |
| private long period = 5000; |
| private long delay; |
| private SchedulerTask schedulerTask; |
| private ScheduleIterator scheduleIterator; |
| private boolean started; |
| private boolean scheduleExecutedFlag; |
| |
| /** |
| * Polls the underlying resource to see if some event is required |
| * |
| * @throws JBIException |
| */ |
| public abstract void poll() throws Exception; |
| |
| public void release() { |
| } |
| |
| public void run() { |
| try { |
| poll(); |
| } catch (Exception e) { |
| LOGGER.error("Caught exception while polling: {}", e.getMessage(), e); |
| } |
| } |
| |
| // Properties |
| // ------------------------------------------------------------------------- |
| public Executor getExecutor() { |
| return executor; |
| } |
| |
| public long getDelay() { |
| return delay; |
| } |
| |
| public void setDelay(long delay) { |
| this.delay = delay; |
| } |
| |
| public Date getFirstTime() { |
| return firstTime; |
| } |
| |
| public void setFirstTime(Date firstTime) { |
| this.firstTime = firstTime; |
| } |
| |
| public long getPeriod() { |
| return period; |
| } |
| |
| public void setPeriod(long period) { |
| this.period = period; |
| } |
| |
| public Scheduler getScheduler() { |
| return scheduler; |
| } |
| |
| public void setScheduler(Scheduler scheduler) { |
| this.scheduler = scheduler; |
| } |
| |
| public synchronized void start() throws JBIException { |
| if (!started) { |
| started = true; |
| if (schedulerTask != null) { |
| schedulerTask.cancel(); |
| } |
| schedulerTask = new PollSchedulerTask(); |
| this.scheduler.schedule(schedulerTask, scheduleIterator); |
| } |
| super.start(); |
| } |
| |
| public synchronized void stop() throws JBIException { |
| if (schedulerTask != null) { |
| schedulerTask.cancel(); |
| schedulerTask = null; |
| } |
| scheduleExecutedFlag = false; |
| started = false; |
| super.stop(); |
| } |
| |
| public synchronized void shutDown() throws JBIException { |
| stop(); |
| scheduler.cancel(); |
| executor.shutdown(); |
| scheduler = null; |
| scheduleIterator = null; |
| executor = null; |
| super.shutDown(); |
| } |
| |
| // Implementation methods |
| // ------------------------------------------------------------------------- |
| protected void init() throws JBIException { |
| if (scheduler == null) { |
| scheduler = new Scheduler(true); |
| } |
| if (scheduleIterator == null) { |
| scheduleIterator = new PollScheduleIterator(); |
| } |
| if (executor == null) { |
| ComponentContextImpl context = (ComponentContextImpl) getContext(); |
| ExecutorFactory factory = context.getContainer() |
| .getExecutorFactory(); |
| executor = factory.createExecutor("component." |
| + context.getComponentName()); |
| } |
| super.init(); |
| |
| } |
| |
| private class PollSchedulerTask extends SchedulerTask { |
| public void run() { |
| try { |
| // lets run the work inside the JCA worker pools to ensure |
| // the threads are setup correctly when we actually do stuff |
| getExecutor().execute(PollingComponentSupport.this); |
| } catch (Throwable e) { |
| LOGGER.error("Failed to schedule work: {}", e.getMessage(), e); |
| } |
| } |
| } |
| |
| private class PollScheduleIterator implements ScheduleIterator { |
| public Date nextExecution() { |
| long nextTime = System.currentTimeMillis(); |
| if (scheduleExecutedFlag) { |
| nextTime += period; |
| } else { |
| if (firstTime != null) { |
| nextTime = firstTime.getTime(); |
| } |
| nextTime += delay; |
| scheduleExecutedFlag = true; |
| } |
| return started ? new Date(nextTime) : null; |
| } |
| } |
| |
| } |