Spring boot定时任务的原理及动态创建详解

}

@Configuration@Role(BeanDefinition.ROLE_INFRASTRUCTURE) public class SchedulingConfiguration {

@Bean(name = TaskManagementConfigUtils.SCHEDULED_ANNOTATION_PROCESSOR_BEAN_NAME)@Role(BeanDefinition.ROLE_INFRASTRUCTURE) public ScheduledAnnotationBeanPostProcessor scheduledAnnotationProcessor() {return new ScheduledAnnotationBeanPostProcessor();}

return bean;}

if (this.beanFactory instanceof ListableBeanFactory) {Map beans =((ListableBeanFactory) this.beanFactory).getBeansOfType(SchedulingConfigurer.class);List configurers = new ArrayList<>(beans.values());AnnotationAwareOrderComparator.sort(configurers);for (SchedulingConfigurer configurer : configurers) {configurer.configureTasks(this.registrar);}}

if (this.registrar.hasTasks() && this.registrar.getScheduler() == null) {Assert.state(this.beanFactory != null, "BeanFactory must be set to find scheduler by type");try {// Search for TaskScheduler bean...

this.registrar.setTaskScheduler(resolveSchedulerBean(this.beanFactory, TaskScheduler.class, false));}catch (NoUniqueBeanDefinitionException ex) {logger.trace("Could not find unique TaskScheduler bean", ex);try {this.registrar.setTaskScheduler(resolveSchedulerBean(this.beanFactory, TaskScheduler.class, true));}catch (NoSuchBeanDefinitionException ex2) {if (logger.isInfoEnabled()) {logger.info("More than one TaskScheduler bean exists within the context, and " +"none is named 'taskScheduler'. Mark one of them as primary or name it 'taskScheduler' " +"(possibly as an alias); or implement the SchedulingConfigurer interface and call " +"ScheduledTaskRegistrar#setScheduler explicitly within the configureTasks() callback: " +ex.getBeanNamesFound());}}}catch (NoSuchBeanDefinitionException ex) {logger.trace("Could not find default TaskScheduler bean", ex);// Search for ScheduledExecutorService bean next...

try {this.registrar.setScheduler(resolveSchedulerBean(this.beanFactory, ScheduledExecutorService.class, false));}catch (NoUniqueBeanDefinitionException ex2) {logger.trace("Could not find unique ScheduledExecutorService bean", ex2);try {this.registrar.setScheduler(resolveSchedulerBean(this.beanFactory, ScheduledExecutorService.class, true));}catch (NoSuchBeanDefinitionException ex3) {if (logger.isInfoEnabled()) {logger.info("More than one ScheduledExecutorService bean exists within the context, and " +"none is named 'taskScheduler'. Mark one of them as primary or name it 'taskScheduler' " +"(possibly as an alias); or implement the SchedulingConfigurer interface and call " +"ScheduledTaskRegistrar#setScheduler explicitly within the configureTasks() callback: " +ex2.getBeanNamesFound());}}}catch (NoSuchBeanDefinitionException ex2) {logger.trace("Could not find default ScheduledExecutorService bean", ex2);// Giving up -> falling back to default scheduler within the registrar...

logger.info("No TaskScheduler/ScheduledExecutorService bean found for scheduled processing");}}}

ConcurrentTaskScheduler.java@Override@Nullable public ScheduledFuture schedule(Runnable task, Trigger trigger) {try {if (this.enterpriseConcurrentScheduler) {return new EnterpriseConcurrentTriggerScheduler().schedule(decorateTask(task, true), trigger);}else {ErrorHandler errorHandler =(this.errorHandler != null ? this.errorHandler : TaskUtils.getDefaultErrorHandler(true));return new ReschedulingRunnable(task, trigger, this.scheduledExecutor, errorHandler).schedule();}}catch (RejectedExecutionException ex) {throw new TaskRejectedException("Executor [" + this.scheduledExecutor + "] did not accept task: " + task, ex);}}

ReschedulingRunnable.java@Nullable public ScheduledFuture schedule() {synchronized (this.triggerContextMonitor) {this.scheduledExecutionTime = this.trigger.nextExecutionTime(this.triggerContext);if (this.scheduledExecutionTime == null) {return null;}long initialDelay = this.scheduledExecutionTime.getTime() - System.currentTimeMillis();this.currentFuture = this.executor.schedule(this, initialDelay, TimeUnit.MILLISECONDS);return this;}}

private ScheduledFuture obtainCurrentFuture() {Assert.state(this.currentFuture != null, "No scheduled future");return this.currentFuture;}

* @param firstTask the first task (null if none)*/ Worker(Runnable firstTask) {setState(-1); // inhibit interrupts until runWorker this.firstTask = firstTask;this.thread = getThreadFactory().newThread(this);}

@Bean(name = ScheduledAnnotationBeanPostProcessor.DEFAULT_TASK_SCHEDULER_BEAN_NAME)@Role(BeanDefinition.ROLE_INFRASTRUCTURE) public ScheduledExecutorService scheduledAnnotationProcessor() {return Executors.newScheduledThreadPool(5, new DefaultThreadFactory());}

private static class DefaultThreadFactory implements ThreadFactory {private static final AtomicInteger poolNumber = new AtomicInteger(1);private final ThreadGroup group;private final AtomicInteger threadNumber = new AtomicInteger(1);private final String namePrefix;

DefaultThreadFactory() {SecurityManager s = System.getSecurityManager();group = (s != null) ? s.getThreadGroup() :Thread.currentThread().getThreadGroup();namePrefix = "pool-" +poolNumber.getAndIncrement() +"-schedule-";}

private static final ExecutorService es = new ThreadPoolExecutor(10, 20,0L, TimeUnit.MILLISECONDS,new LinkedBlockingQueue<>(10),new DynamicTaskConsumeThreadFactory());

private volatile ScheduledTaskRegistrar registrar;private final ConcurrentHashMap> scheduledFutures = new ConcurrentHashMap<>();private final ConcurrentHashMap cronTasks = new ConcurrentHashMap<>();

private volatile List taskConstants = Lists.newArrayList();

@Override public void configureTasks(ScheduledTaskRegistrar registrar) {this.registrar = registrar;this.registrar.addTriggerTask(() -> {if (!CollectionUtils.isEmpty(taskConstants)) {LOGGER.info("检测动态定时任务列表...");List tts = new ArrayList<>();taskConstants.forEach(taskConstant -> {TimingTask tt = new TimingTask();tt.setExpression(taskConstant.getCron());tt.setTaskId("dynamic-task-" + taskConstant.getTaskId());tts.add(tt);});this.refreshTasks(tts);}}, triggerContext -> new PeriodicTrigger(5L, TimeUnit.SECONDS).nextExecutionTime(triggerContext));}

public List getTaskConstants() {return taskConstants;}

private void refreshTasks(List tasks) {//取消已经删除的策略任务Set taskIds = scheduledFutures.keySet();for (String taskId : taskIds) {if (!exists(tasks, taskId)) {scheduledFutures.get(taskId).cancel(false);}}for (TimingTask tt : tasks) {String expression = tt.getExpression();if (StringUtils.isBlank(expression) || !CronSequenceGenerator.isValidExpression(expression)) {LOGGER.error("定时任务DynamicTask cron表达式不合法: " + expression);continue;}//如果配置一致，则不需要重新创建定时任务if (scheduledFutures.containsKey(tt.getTaskId())&& cronTasks.get(tt.getTaskId()).getExpression().equals(expression)) {continue;}//如果策略执行时间发生了变化，则取消当前策略的任务if (scheduledFutures.containsKey(tt.getTaskId())) {scheduledFutures.remove(tt.getTaskId()).cancel(false);cronTasks.remove(tt.getTaskId());}CronTask task = new CronTask(tt, expression);ScheduledFuture future = registrar.getScheduler().schedule(task.getRunnable(), task.getTrigger());cronTasks.put(tt.getTaskId(), task);scheduledFutures.put(tt.getTaskId(), future);}}

private boolean exists(List tasks, String taskId) {for (TimingTask task : tasks) {if (task.getTaskId().equals(taskId)) {return true;}}return false;}

@PreDestroy public void destroy() {this.registrar.destroy();}

public static class TaskConstant {private String cron;private String taskId;

public String getCron() {return cron;}

public void setCron(String cron) {this.cron = cron;}

public String getTaskId() {return taskId;}

public void setTaskId(String taskId) {this.taskId = taskId;}}

private class TimingTask implements Runnable {private String expression;

private String taskId;

public String getTaskId() {return taskId;}

public void setTaskId(String taskId) {this.taskId = taskId;}

@Override public void run() {//设置队列大小10 LOGGER.error("当前CronTask: " + this);DynamicBlockingQueue queue = new DynamicBlockingQueue(3);es.submit(() -> {while (!queue.isDone() || !queue.isEmpty()) {try {String content = queue.poll(500, TimeUnit.MILLISECONDS);if (StringUtils.isBlank(content)) {return;}LOGGER.info("DynamicBlockingQueue 消费：" + content);TimeUnit.MILLISECONDS.sleep(500);} catch (InterruptedException e) {e.printStackTrace();}}});

//队列放入数据for (int i = 0; i < 5; ++i) {try {queue.put(String.valueOf(i));LOGGER.info("DynamicBlockingQueue 生产：" + i);} catch (InterruptedException e) {e.printStackTrace();}}queue.setDone(true);}

public String getExpression() {return expression;}

public void setExpression(String expression) {this.expression = expression;}

@Override public String toString() {return ReflectionToStringBuilder.toString(this, ToStringStyle.JSON_STYLE, false, false, TimingTask.class);}

}

/*** 队列消费线程工厂类*/ private static class DynamicTaskConsumeThreadFactory implements ThreadFactory {private static final AtomicInteger poolNumber = new AtomicInteger(1);private final ThreadGroup group;private final AtomicInteger threadNumber = new AtomicInteger(1);private final String namePrefix;

DynamicTaskConsumeThreadFactory() {SecurityManager s = System.getSecurityManager();group = (s != null) ? s.getThreadGroup() :Thread.currentThread().getThreadGroup();namePrefix = "pool-" +poolNumber.getAndIncrement() +"-dynamic-task-";}

@Override public Thread newThread(Runnable r) {Thread t = new Thread(group, r,namePrefix + threadNumber.getAndIncrement(),0);if (t.isDaemon()) {t.setDaemon(false);}if (t.getPriority() != Thread.NORM_PRIORITY) {t.setPriority(Thread.NORM_PRIORITY);}return t;}}

private static class DynamicBlockingQueue extends LinkedBlockingQueue {DynamicBlockingQueue(int capacity) {super(capacity);}

private volatile boolean done = false;

public boolean isDone() {return done;}

@Autowired private DynamicTask dynamicTask;

@Test public void test() throws InterruptedException {List taskConstans = dynamicTask.getTaskConstants();DynamicTask.TaskConstant taskConstant = new DynamicTask.TaskConstant();taskConstant.setCron("0/5 * * * * ?");taskConstant.setTaskId("test1");taskConstans.add(taskConstant);

DynamicTask.TaskConstant taskConstant1 = new DynamicTask.TaskConstant();taskConstant1.setCron("0/5 * * * * ?");taskConstant1.setTaskId("test2");taskConstans.add(taskConstant1);

DynamicTask.TaskConstant taskConstant2 = new DynamicTask.TaskConstant();taskConstant2.setCron("0/5 * * * * ?");taskConstant2.setTaskId("test3");taskConstans.add(taskConstant2);