如何中断正在执行IO的 Quartz 作业

Interrupt a Quartz job that doing IO

如果你想中断正在执行IO的 Quartz 作业，在你使用 InterruptibleChannel 时这是可行的。引用一下Oracle链接：实现了这个接口的通道，是可中断的：如果一个线程在一个中断通道阻塞I/O操作，另一个线程能调用阻塞的线程的中断方法。这将导致的通道被关闭，被阻塞的线程收到一个ClosedByInterruptException，设置被阻塞的线程的中断状态。因此，获得自己工作的执行线程的作业计划，能保存供以后使用。当Quartz调度中断作业，你可以再调用该线程的interrupt（）方法来停止读/写操作。这里有一个简单的例子：

package demo;

// import statements excluded for brevity

public class MyJob implements InterruptableJob {

private static Logger    LOG              = LoggerFactory.getLogger(MyJob.class);

private volatile boolean isJobInterrupted = false;

private JobKey           jobKey           = null;

private volatile Thread  thisThread;

public MyJob() {
}

public void execute(JobExecutionContext context) throws JobExecutionException {
thisThread = Thread.currentThread();
LOG.info("Thread name of the current job: " + thisThread.getName());

jobKey = context.getJobDetail().getKey();
LOG.info("Job " + jobKey + " executing at " + new Date());

try {
String fileUrl = "http://d2zwv9pap9ylyd.cloudfront.net/terracotta-3.6.1.tar.gz"; // 59 MB
String localFile = "terracotta-3.6.1.tar.gz";
download(fileUrl, localFile);
} catch (ClosedByInterruptException e) {
LOG.info("Caught ClosedByInterruptException... exiting job.");
} catch (IOException e) {
LOG.info("Caught IOException... exiting job.", e);
} finally {
if (isJobInterrupted) {
LOG.info("Job " + jobKey + " did not complete");
} else {
LOG.info("Job " + jobKey + " completed at " + new Date());
}
}
}

// this method is called by the scheduler
public void interrupt() throws UnableToInterruptJobException {
LOG.info("Job " + jobKey + "  -- INTERRUPTING --");
isJobInterrupted = true;
if (thisThread != null) {
// this called cause the ClosedByInterruptException to happen
thisThread.interrupt();
}
}

private void download(String address, String localFileName) throws ClosedByInterruptException, IOException {
URL url = new URL(address);
ReadableByteChannel src = Channels.newChannel(url.openStream());
WritableByteChannel dest = new FileOutputStream(new File(localFileName)).getChannel();
try {
System.out.println("Downloading " + address + " to " + new File(localFileName).getCanonicalPath());
int size = fastChannelCopy(src, dest);
System.out.println("Download completed! " + (size / 1024 / 1024) + " MB");
} finally {
src.close();
dest.close();
}
}

// Code copied from http://thomaswabner.wordpress.com/2007/10/09/fast-stream-copy-using-javanio-channels/ private static int fastChannelCopy(final ReadableByteChannel src, final WritableByteChannel dest) throws IOException {
final ByteBuffer buffer = ByteBuffer.allocateDirect(16 * 1024);
int count = 0;
int total = 0;
while ((count = src.read(buffer)) != -1) {
total += count;
// prepare the buffer to be drained
buffer.flip();
// write to the channel, may block
dest.write(buffer);
// If partial transfer, shift remainder down
// If buffer is empty, same as doing clear()
buffer.compact();
}
// EOF will leave buffer in fill state
buffer.flip();
// make sure the buffer is fully drained.
while (buffer.hasRemaining()) {
dest.write(buffer);
}
return total;
}
}

这是我的主类，创建Quartz Scheduler和模拟预期的中断。下载将需要大约40秒完成（59MB文件）。为了看到我们的作业确实是在下载过程中中断，我们启动调度然后休息5秒。注：如果您想看到的作业完成，休息了约40秒。

package demo;

import static org.quartz.DateBuilder.nextGivenSecondDate;
import static org.quartz.JobBuilder.newJob;
import static org.quartz.SimpleScheduleBuilder.simpleSchedule;
import static org.quartz.TriggerBuilder.newTrigger;

// other imports excluded for brevity

public class InterruptExample {

public void run() throws Exception {
final Logger log = LoggerFactory.getLogger(InterruptExample.class);

log.info("------- Initializing ----------------------");

// First we must get a reference to a scheduler
SchedulerFactory sf = new StdSchedulerFactory();
Scheduler sched = sf.getScheduler();

log.info("------- Initialization Complete -----------");

log.info("------- Scheduling Jobs -------------------");

// get a "nice round" time a few seconds in the future...
Date startTime = nextGivenSecondDate(null, 1);

JobDetail job = newJob(MyJob.class).withIdentity("myJob", "group1").build();

SimpleTrigger trigger = newTrigger().withIdentity("trigger1", "group1").startAt(startTime)
.withSchedule(simpleSchedule()).build();

sched.scheduleJob(job, trigger);

// start up the scheduler (jobs do not start to fire until
// the scheduler has been started)
sched.start();
log.info("Scheduler thread's name: " + Thread.currentThread().getName());
log.info("------- Started Scheduler -----------------");

try {
// if you want to see the job to finish successfully, sleep for about 40 seconds
Thread.sleep(5 * 1000L);
// tell the scheduler to interrupt our job
sched.interrupt(job.getKey());
Thread.sleep(3 * 1000L);
} catch (Exception e) {
e.printStackTrace();
}

log.info("------- Shutting Down ---------------------");

sched.shutdown(true);

log.info("------- Shutdown Complete -----------------");
}

public static void main(String[] args) throws Exception {
InterruptExample example = new InterruptExample();
example.run();
}
}

这是日志，说明我们的作业被intterupted提早退出

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

INFO [main] ------- Initializing ---------------------- INFO [main] Using default implementation for ThreadExecutor INFO [main] Job execution threads will use class loader of thread: main INFO [main] Initialized Scheduler Signaller of type: class org.quartz.core.SchedulerSignalerImpl INFO [main] Quartz Scheduler v.2.1.3 created. INFO [main] RAMJobStore initialized. INFO [main] Scheduler meta-data: Quartz Scheduler (v2.1.3) 'DefaultQuartzScheduler' with instanceId 'NON_CLUSTERED' Scheduler class: 'org.quartz.core.QuartzScheduler' - running locally. NOT STARTED. Currently in standby mode. Number of jobs executed: 0 Using thread pool 'org.quartz.simpl.SimpleThreadPool' - with 10 threads. Using job-store 'org.quartz.simpl.RAMJobStore' - which does not support persistence. and is not clustered. INFO [main] Quartz scheduler 'DefaultQuartzScheduler' initialized from default resource file in Quartz package: 'quartz.properties' INFO [main] Quartz scheduler version: 2.1.3 INFO [main] ------- Initialization Complete ----------- INFO [main] ------- Scheduling Jobs ------------------- INFO [main] Scheduler DefaultQuartzScheduler_$_NON_CLUSTERED started. INFO [main] Scheduler thread's name: main INFO [main] ------- Started Scheduler ----------------- INFO [DefaultQuartzScheduler_Worker-1] Thread name of the current job: DefaultQuartzScheduler_Worker-1 NFO [DefaultQuartzScheduler_Worker-1] Job group1.myJob executing at Mon Apr 16 16:24:40 PDT 2012 Downloading http://d2zwv9pap9ylyd.cloudfront.net/terracotta-3.6.1.tar.gz to S:\quartz-interrupt-demo\terracotta-3.6.1.tar.gz INFO [main] Job group1.myJob -- INTERRUPTING -- INFO [DefaultQuartzScheduler_Worker-1] Caught ClosedByInterruptException... exiting job. INFO [DefaultQuartzScheduler_Worker-1] Job group1.myJob did not complete ERROR [DefaultQuartzScheduler_Worker-1] Worker thread was interrupt()'ed. java.lang.InterruptedException at java.lang.Object.wait(Native Method) at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:552) INFO [main] ------- Shutting Down --------------------- INFO [main] Scheduler DefaultQuartzScheduler_$_NON_CLUSTERED shutting down. INFO [main] Scheduler DefaultQuartzScheduler_$_NON_CLUSTERED paused. INFO [main] Scheduler DefaultQuartzScheduler_$_NON_CLUSTERED shutdown complete. INFO [main] ------- Shutdown Complete -----------------

原文：http://itindex.net/blog/2012/04/23/1335149680608.html