初认识
基本使用
1、添加基本依赖
2、
@EnableScheduling 注解开启定时任务
@Scheduled 注释标注定时任务方法
通过注册ScheduledAnnotationBeanPostProcessor来执行@Scheduled注释的处理。这可以手动完成，或者更方便地通过task:annotation-driven/XML元素或@EnableScheduling annotation来完成。
三种触发器
实际运行一下
import lombok.extern.slf4j.Slf4j;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
/**
* @author xiyan
* @date 2023/7/5 14:36
*/
@Slf4j
@EnableScheduling
@Component
public class DemoScheduledTest {
/**
* 固定延迟时间
* 间隔 5s ，执行 3s、实际间隔8s
* 2023-07-06 17:36:05.068
* 2023-07-06 17:36:13.091
* 2023-07-06 17:36:21.109
* 2023-07-06 17:36:29.134
* 2023-07-06 17:36:37.149
* <p>
* 间隔 5s ，执行 5s、实际间隔10s
* 2023-07-05 14:38:46.182
* 2023-07-05 14:38:56.196
* 2023-07-05 14:39:06.210
* 2023-07-05 14:39:16.235
* 2023-07-05 14:39:26.244
* <p>
* 间隔 5s ，执行 7s、实际间隔12s
* 2023-07-05 14:45:02.764
* 2023-07-05 14:45:14.775
* 2023-07-05 14:45:26.796
* 2023-07-05 14:45:38.814
* 2023-07-05 14:45:50.830
* <p>
* 下次执行时间=上次执行时间+(fixedDelay时间+执行耗时)
*/
@Scheduled(fixedDelay = 5000)
public void test1() {
try {
log.info("test1方法执行=====>>>>");
Thread.sleep(3000);
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
/**
* 固定间隔时间
* 间隔5s、执行3s、实际间隔5s
* 2023-07-06 18:00:11.362
* 2023-07-06 18:00:16.352
* 2023-07-06 18:00:21.358
* 2023-07-06 18:00:26.355
* 2023-07-06 18:00:31.364
* <p>
* 间隔 5s ，执行 5s、实际间隔5s
* 2023-07-05 14:40:39.180
* 2023-07-05 14:40:44.185
* 2023-07-05 14:40:49.200
* 2023-07-05 14:40:54.212
* 2023-07-05 14:40:59.226
* <p>
* 间隔5s，执行7s、实际间隔7s
* 2023-07-05 14:41:45.559
* 2023-07-05 14:41:52.567
* 2023-07-05 14:41:59.581
* 2023-07-05 14:42:06.588
* 2023-07-05 14:42:13.593
* <p>
* 下次执行时间=上次执行时间+ max(fixedRate, 执行耗时)
*/
@Scheduled(fixedRate = 5000)
public void test2() {
try {
log.info("test2方法执行=====>>>>");
Thread.sleep(3000);
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
/**
* cron表达式
* <p>
* 间隔5s、执行3s、实际间隔5s
* 2023-07-06 17:55:10.015
* 2023-07-06 17:55:15.001
* 2023-07-06 17:55:20.014
* 2023-07-06 17:55:25.007
* 2023-07-06 17:55:30.008
* <p>
* 间隔 5s ，执行 5s、实际间隔10s
* 2023-07-06 17:49:55.008
* 2023-07-06 17:50:05.014
* 2023-07-06 17:50:15.000
* 2023-07-06 17:50:25.004
* 2023-07-06 17:50:35.005
* <p>
* 间隔5s，执行7s、实际间隔10s
* 2023-07-06 17:51:55.016
* 2023-07-06 17:52:05.008
* 2023-07-06 17:52:15.001
* 2023-07-06 17:52:25.010
* 2023-07-06 17:52:35.014
* <p>
* 下次执行时间=如果到达定时时间，上一个任务已完成，将会执行，否则会跳过
*/
@Scheduled(cron = "0/5 * * * * ?")
public void test3() {
try {
log.info("test3方法执行=====>>>>");
Thread.sleep(5000);
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
}
为什么会这样
运行原理
/**
Bean后处理器，注册用@Scheduled注释的方法，以便由TaskScheduler根据通过注释提供的“fixedRate”、“fixedDelay”或“cron”表达式调用。
这个后处理器由Spring的<task:annotation-driven>XML元素以及@EnableScheduling注释自动注册。
自动检测容器中的任何SchedulingConfigurer实例，允许自定义要使用的计划程序或对任务注册进行细粒度控制（例如，注册触发器任务）。
*/
org.springframework.scheduling.annotation.ScheduledAnnotationBeanPostProcessor
关键类
/**
* Bean post-processor that registers methods annotated with
* {@link Scheduled @Scheduled} to be invoked by a
* {@link org.springframework.scheduling.TaskScheduler} according to the
* "fixedRate", "fixedDelay", or "cron" expression provided via the annotation.
*
* <p>This post-processor is automatically registered by Spring's
* {@code <task:annotation-driven>} XML element, and also by the
* {@link EnableScheduling @EnableScheduling} annotation.
*
* <p>Autodetects any {@link SchedulingConfigurer} instances in the container,
* allowing for customization of the scheduler to be used or for fine-grained
* control over task registration (e.g. registration of {@link Trigger} tasks).
* See the {@link EnableScheduling @EnableScheduling} javadocs for complete usage
* details.
*
* @author Mark Fisher
* @author Juergen Hoeller
* @author Chris Beams
* @author Elizabeth Chatman
* @author Victor Brown
* @author Sam Brannen
* @since 3.0
* @see Scheduled
* @see EnableScheduling
* @see SchedulingConfigurer
* @see org.springframework.scheduling.TaskScheduler
* @see org.springframework.scheduling.config.ScheduledTaskRegistrar
* @see AsyncAnnotationBeanPostProcessor
*/
public class ScheduledAnnotationBeanPostProcessor
implements ScheduledTaskHolder, MergedBeanDefinitionPostProcessor, DestructionAwareBeanPostProcessor,
Ordered, EmbeddedValueResolverAware, BeanNameAware, BeanFactoryAware, ApplicationContextAware,
SmartInitializingSingleton, ApplicationListener<ContextRefreshedEvent>, DisposableBean {
/**
* The default name of the {@link TaskScheduler} bean to pick up: {@value}.
* <p>Note that the initial lookup happens by type; this is just the fallback
* in case of multiple scheduler beans found in the context.
* @since 4.2
*/
public static final String DEFAULT_TASK_SCHEDULER_BEAN_NAME = "taskScheduler";
protected final Log logger = LogFactory.getLog(getClass());
private final ScheduledTaskRegistrar registrar;
@Nullable
private Object scheduler;
@Nullable
private StringValueResolver embeddedValueResolver;
@Nullable
private String beanName;
@Nullable
private BeanFactory beanFactory;
@Nullable
private ApplicationContext applicationContext;
private final Set<Class<?>> nonAnnotatedClasses = Collections.newSetFromMap(new ConcurrentHashMap<>(64));
private final Map<Object, Set<ScheduledTask>> scheduledTasks = new IdentityHashMap<>(16);
/**
* Create a default {@code ScheduledAnnotationBeanPostProcessor}.
*/
public ScheduledAnnotationBeanPostProcessor() {
this.registrar = new ScheduledTaskRegistrar();
}
/**
* Create a {@code ScheduledAnnotationBeanPostProcessor} delegating to the
* specified {@link ScheduledTaskRegistrar}.
* @param registrar the ScheduledTaskRegistrar to register {@code @Scheduled}
* tasks on
* @since 5.1
*/
public ScheduledAnnotationBeanPostProcessor(ScheduledTaskRegistrar registrar) {
Assert.notNull(registrar, "ScheduledTaskRegistrar is required");
this.registrar = registrar;
}
@Override
public int getOrder() {
return LOWEST_PRECEDENCE;
}
/**
* Set the {@link org.springframework.scheduling.TaskScheduler} that will invoke
* the scheduled methods, or a {@link java.util.concurrent.ScheduledExecutorService}
* to be wrapped as a TaskScheduler.
* <p>If not specified, default scheduler resolution will apply: searching for a
* unique {@link TaskScheduler} bean in the context, or for a {@link TaskScheduler}
* bean named "taskScheduler" otherwise; the same lookup will also be performed for
* a {@link ScheduledExecutorService} bean. If neither of the two is resolvable,
* a local single-threaded default scheduler will be created within the registrar.
* @see #DEFAULT_TASK_SCHEDULER_BEAN_NAME
*/
public void setScheduler(Object scheduler) {
this.scheduler = scheduler;
}
@Override
public void setEmbeddedValueResolver(StringValueResolver resolver) {
this.embeddedValueResolver = resolver;
}
@Override
public void setBeanName(String beanName) {
this.beanName = beanName;
}
/**
* Making a {@link BeanFactory} available is optional; if not set,
* {@link SchedulingConfigurer} beans won't get autodetected and
* a {@link #setScheduler scheduler} has to be explicitly configured.
*/
@Override
public void setBeanFactory(BeanFactory beanFactory) {
this.beanFactory = beanFactory;
}
/**
* Setting an {@link ApplicationContext} is optional: If set, registered
* tasks will be activated in the {@link ContextRefreshedEvent} phase;
* if not set, it will happen at {@link #afterSingletonsInstantiated} time.
*/
@Override
public void setApplicationContext(ApplicationContext applicationContext) {
this.applicationContext = applicationContext;
if (this.beanFactory == null) {
this.beanFactory = applicationContext;
}
}
@Override
public void afterSingletonsInstantiated() {
// Remove resolved singleton classes from cache
this.nonAnnotatedClasses.clear();
if (this.applicationContext == null) {
// Not running in an ApplicationContext -> register tasks early...
finishRegistration();
}
}
@Override
public void onApplicationEvent(ContextRefreshedEvent event) {
if (event.getApplicationContext() == this.applicationContext) {
// Running in an ApplicationContext -> register tasks this late...
// giving other ContextRefreshedEvent listeners a chance to perform
// their work at the same time (e.g. Spring Batch's job registration).
finishRegistration();
}
}
/**
* 关键的注册逻辑
*/
private void finishRegistration() {
if (this.scheduler != null) {
this.registrar.setScheduler(this.scheduler);
}
// 解析实现了 SchedulingConfigurer 接口的注册类，编程式任务注册
if (this.beanFactory instanceof ListableBeanFactory) {
Map<String, SchedulingConfigurer> beans =
((ListableBeanFactory) this.beanFactory).getBeansOfType(SchedulingConfigurer.class);
List<SchedulingConfigurer> configurers = new ArrayList<>(beans.values());
AnnotationAwareOrderComparator.sort(configurers);
for (SchedulingConfigurer configurer : configurers) {
configurer.configureTasks(this.registrar);
}
}
// 如果注册器中有任务，则注册任务
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) {
if (logger.isTraceEnabled()) {
logger.trace("Could not find unique TaskScheduler bean - attempting to resolve by name: " +
ex.getMessage());
}
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) {
if (logger.isTraceEnabled()) {
logger.trace("Could not find default TaskScheduler bean - attempting to find ScheduledExecutorService: " +
ex.getMessage());
}
// Search for ScheduledExecutorService bean next...
try {
this.registrar.setScheduler(resolveSchedulerBean(this.beanFactory, ScheduledExecutorService.class, false));
}
catch (NoUniqueBeanDefinitionException ex2) {
if (logger.isTraceEnabled()) {
logger.trace("Could not find unique ScheduledExecutorService bean - attempting to resolve by name: " +
ex2.getMessage());
}
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) {
if (logger.isTraceEnabled()) {
logger.trace("Could not find default ScheduledExecutorService bean - falling back to default: " +
ex2.getMessage());
}
// Giving up -> falling back to default scheduler within the registrar...
logger.info("No TaskScheduler/ScheduledExecutorService bean found for scheduled processing");
}
}
}
this.registrar.afterPropertiesSet();
}
private <T> T resolveSchedulerBean(BeanFactory beanFactory, Class<T> schedulerType, boolean byName) {
if (byName) {
T scheduler = beanFactory.getBean(DEFAULT_TASK_SCHEDULER_BEAN_NAME, schedulerType);
if (this.beanName != null && this.beanFactory instanceof ConfigurableBeanFactory) {
((ConfigurableBeanFactory) this.beanFactory).registerDependentBean(
DEFAULT_TASK_SCHEDULER_BEAN_NAME, this.beanName);
}
return scheduler;
}
else if (beanFactory instanceof AutowireCapableBeanFactory) {
NamedBeanHolder<T> holder = ((AutowireCapableBeanFactory) beanFactory).resolveNamedBean(schedulerType);
if (this.beanName != null && beanFactory instanceof ConfigurableBeanFactory) {
((ConfigurableBeanFactory) beanFactory).registerDependentBean(holder.getBeanName(), this.beanName);
}
return holder.getBeanInstance();
}
else {
return beanFactory.getBean(schedulerType);
}
}
@Override
public void postProcessMergedBeanDefinition(RootBeanDefinition beanDefinition, Class<?> beanType, String beanName) {
}
@Override
public Object postProcessBeforeInitialization(Object bean, String beanName) {
return bean;
}
@Override
public Object postProcessAfterInitialization(Object bean, String beanName) {
if (bean instanceof AopInfrastructureBean || bean instanceof TaskScheduler ||
bean instanceof ScheduledExecutorService) {
// Ignore AOP infrastructure such as scoped proxies.
return bean;
}
Class<?> targetClass = AopProxyUtils.ultimateTargetClass(bean);
if (!this.nonAnnotatedClasses.contains(targetClass) &&
AnnotationUtils.isCandidateClass(targetClass, Arrays.asList(Scheduled.class, Schedules.class))) {
Map<Method, Set<Scheduled>> annotatedMethods = MethodIntrospector.selectMethods(targetClass,
(MethodIntrospector.MetadataLookup<Set<Scheduled>>) method -> {
Set<Scheduled> scheduledAnnotations = AnnotatedElementUtils.getMergedRepeatableAnnotations(
method, Scheduled.class, Schedules.class);
return (!scheduledAnnotations.isEmpty() ? scheduledAnnotations : null);
});
if (annotatedMethods.isEmpty()) {
this.nonAnnotatedClasses.add(targetClass);
if (logger.isTraceEnabled()) {
logger.trace("No @Scheduled annotations found on bean class: " + targetClass);
}
}
else {
// Non-empty set of methods
annotatedMethods.forEach((method, scheduledAnnotations) ->
scheduledAnnotations.forEach(scheduled -> processScheduled(scheduled, method, bean)));
if (logger.isTraceEnabled()) {
logger.trace(annotatedMethods.size() + " @Scheduled methods processed on bean '" + beanName +
"': " + annotatedMethods);
}
}
}
return bean;
}
/**
* Process the given {@code @Scheduled} method declaration on the given bean.
* @param scheduled the {@code @Scheduled} annotation
* @param method the method that the annotation has been declared on
* @param bean the target bean instance
* @see #createRunnable(Object, Method)
*/
protected void processScheduled(Scheduled scheduled, Method method, Object bean) {
try {
Runnable runnable = createRunnable(bean, method);
boolean processedSchedule = false;
String errorMessage =
"Exactly one of the 'cron', 'fixedDelay(String)', or 'fixedRate(String)' attributes is required";
Set<ScheduledTask> tasks = new LinkedHashSet<>(4);
// Determine initial delay
long initialDelay = convertToMillis(scheduled.initialDelay(), scheduled.timeUnit());
String initialDelayString = scheduled.initialDelayString();
if (StringUtils.hasText(initialDelayString)) {
Assert.isTrue(initialDelay < 0, "Specify 'initialDelay' or 'initialDelayString', not both");
if (this.embeddedValueResolver != null) {
initialDelayString = this.embeddedValueResolver.resolveStringValue(initialDelayString);
}
if (StringUtils.hasLength(initialDelayString)) {
try {
initialDelay = convertToMillis(initialDelayString, scheduled.timeUnit());
}
catch (RuntimeException ex) {
throw new IllegalArgumentException(
"Invalid initialDelayString value \"" + initialDelayString + "\" - cannot parse into long");
}
}
}
// Check cron expression
String cron = scheduled.cron();
if (StringUtils.hasText(cron)) {
String zone = scheduled.zone();
if (this.embeddedValueResolver != null) {
cron = this.embeddedValueResolver.resolveStringValue(cron);
zone = this.embeddedValueResolver.resolveStringValue(zone);
}
if (StringUtils.hasLength(cron)) {
Assert.isTrue(initialDelay == -1, "'initialDelay' not supported for cron triggers");
processedSchedule = true;
if (!Scheduled.CRON_DISABLED.equals(cron)) {
TimeZone timeZone;
if (StringUtils.hasText(zone)) {
timeZone = StringUtils.parseTimeZoneString(zone);
}
else {
timeZone = TimeZone.getDefault();
}
tasks.add(this.registrar.scheduleCronTask(new CronTask(runnable, new CronTrigger(cron, timeZone))));
}
}
}
// At this point we don't need to differentiate between initial delay set or not anymore
if (initialDelay < 0) {
initialDelay = 0;
}
// Check fixed delay
long fixedDelay = convertToMillis(scheduled.fixedDelay(), scheduled.timeUnit());
if (fixedDelay >= 0) {
Assert.isTrue(!processedSchedule, errorMessage);
processedSchedule = true;
tasks.add(this.registrar.scheduleFixedDelayTask(new FixedDelayTask(runnable, fixedDelay, initialDelay)));
}
String fixedDelayString = scheduled.fixedDelayString();
if (StringUtils.hasText(fixedDelayString)) {
if (this.embeddedValueResolver != null) {
fixedDelayString = this.embeddedValueResolver.resolveStringValue(fixedDelayString);
}
if (StringUtils.hasLength(fixedDelayString)) {
Assert.isTrue(!processedSchedule, errorMessage);
processedSchedule = true;
try {
fixedDelay = convertToMillis(fixedDelayString, scheduled.timeUnit());
}
catch (RuntimeException ex) {
throw new IllegalArgumentException(
"Invalid fixedDelayString value \"" + fixedDelayString + "\" - cannot parse into long");
}
tasks.add(this.registrar.scheduleFixedDelayTask(new FixedDelayTask(runnable, fixedDelay, initialDelay)));
}
}
// Check fixed rate
long fixedRate = convertToMillis(scheduled.fixedRate(), scheduled.timeUnit());
if (fixedRate >= 0) {
Assert.isTrue(!processedSchedule, errorMessage);
processedSchedule = true;
tasks.add(this.registrar.scheduleFixedRateTask(new FixedRateTask(runnable, fixedRate, initialDelay)));
}
String fixedRateString = scheduled.fixedRateString();
if (StringUtils.hasText(fixedRateString)) {
if (this.embeddedValueResolver != null) {
fixedRateString = this.embeddedValueResolver.resolveStringValue(fixedRateString);
}
if (StringUtils.hasLength(fixedRateString)) {
Assert.isTrue(!processedSchedule, errorMessage);
processedSchedule = true;
try {
fixedRate = convertToMillis(fixedRateString, scheduled.timeUnit());
}
catch (RuntimeException ex) {
throw new IllegalArgumentException(
"Invalid fixedRateString value \"" + fixedRateString + "\" - cannot parse into long");
}
tasks.add(this.registrar.scheduleFixedRateTask(new FixedRateTask(runnable, fixedRate, initialDelay)));
}
}
// Check whether we had any attribute set
Assert.isTrue(processedSchedule, errorMessage);
// Finally register the scheduled tasks
synchronized (this.scheduledTasks) {
Set<ScheduledTask> regTasks = this.scheduledTasks.computeIfAbsent(bean, key -> new LinkedHashSet<>(4));
regTasks.addAll(tasks);
}
}
catch (IllegalArgumentException ex) {
throw new IllegalStateException(
"Encountered invalid @Scheduled method '" + method.getName() + "': " + ex.getMessage());
}
}
/**
* Create a {@link Runnable} for the given bean instance,
* calling the specified scheduled method.
* <p>The default implementation creates a {@link ScheduledMethodRunnable}.
* @param target the target bean instance
* @param method the scheduled method to call
* @since 5.1
* @see ScheduledMethodRunnable#ScheduledMethodRunnable(Object, Method)
*/
protected Runnable createRunnable(Object target, Method method) {
Assert.isTrue(method.getParameterCount() == 0, "Only no-arg methods may be annotated with @Scheduled");
Method invocableMethod = AopUtils.selectInvocableMethod(method, target.getClass());
return new ScheduledMethodRunnable(target, invocableMethod);
}
private static long convertToMillis(long value, TimeUnit timeUnit) {
return TimeUnit.MILLISECONDS.convert(value, timeUnit);
}
private static long convertToMillis(String value, TimeUnit timeUnit) {
if (isDurationString(value)) {
return Duration.parse(value).toMillis();
}
return convertToMillis(Long.parseLong(value), timeUnit);
}
private static boolean isDurationString(String value) {
return (value.length() > 1 && (isP(value.charAt(0)) || isP(value.charAt(1))));
}
private static boolean isP(char ch) {
return (ch == 'P' || ch == 'p');
}
/**
* Return all currently scheduled tasks, from {@link Scheduled} methods
* as well as from programmatic {@link SchedulingConfigurer} interaction.
* @since 5.0.2
*/
@Override
public Set<ScheduledTask> getScheduledTasks() {
Set<ScheduledTask> result = new LinkedHashSet<>();
synchronized (this.scheduledTasks) {
Collection<Set<ScheduledTask>> allTasks = this.scheduledTasks.values();
for (Set<ScheduledTask> tasks : allTasks) {
result.addAll(tasks);
}
}
result.addAll(this.registrar.getScheduledTasks());
return result;
}
@Override
public void postProcessBeforeDestruction(Object bean, String beanName) {
Set<ScheduledTask> tasks;
synchronized (this.scheduledTasks) {
tasks = this.scheduledTasks.remove(bean);
}
if (tasks != null) {
for (ScheduledTask task : tasks) {
task.cancel();
}
}
}
@Override
public boolean requiresDestruction(Object bean) {
synchronized (this.scheduledTasks) {
return this.scheduledTasks.containsKey(bean);
}
}
@Override
public void destroy() {
synchronized (this.scheduledTasks) {
Collection<Set<ScheduledTask>> allTasks = this.scheduledTasks.values();
for (Set<ScheduledTask> tasks : allTasks) {
for (ScheduledTask task : tasks) {
task.cancel();
}
}
this.scheduledTasks.clear();
}
this.registrar.destroy();
}
}
第二个关键类
/**
* Helper bean for registering tasks with a {@link TaskScheduler}, typically using cron
* expressions.
*
* <p>As of Spring 3.1, {@code ScheduledTaskRegistrar} has a more prominent user-facing
* role when used in conjunction with the {@link
* org.springframework.scheduling.annotation.EnableAsync @EnableAsync} annotation and its
* {@link org.springframework.scheduling.annotation.SchedulingConfigurer
* SchedulingConfigurer} callback interface.
*
* @author Juergen Hoeller
* @author Chris Beams
* @author Tobias Montagna-Hay
* @author Sam Brannen
* @since 3.0
* @see org.springframework.scheduling.annotation.EnableAsync
* @see org.springframework.scheduling.annotation.SchedulingConfigurer
*/
public class ScheduledTaskRegistrar implements ScheduledTaskHolder, InitializingBean, DisposableBean {
/**
* A special cron expression value that indicates a disabled trigger: {@value}.
* <p>This is primarily meant for use with {@link #addCronTask(Runnable, String)}
* when the value for the supplied {@code expression} is retrieved from an
* external source — for example, from a property in the
* {@link org.springframework.core.env.Environment Environment}.
* @since 5.2
* @see org.springframework.scheduling.annotation.Scheduled#CRON_DISABLED
*/
public static final String CRON_DISABLED = "-";
@Nullable
private TaskScheduler taskScheduler;
@Nullable
private ScheduledExecutorService localExecutor;
@Nullable
private List<TriggerTask> triggerTasks;
@Nullable
private List<CronTask> cronTasks;
@Nullable
private List<IntervalTask> fixedRateTasks;
@Nullable
private List<IntervalTask> fixedDelayTasks;
private final Map<Task, ScheduledTask> unresolvedTasks = new HashMap<>(16);
private final Set<ScheduledTask> scheduledTasks = new LinkedHashSet<>(16);
/**
* Set the {@link TaskScheduler} to register scheduled tasks with.
*/
public void setTaskScheduler(TaskScheduler taskScheduler) {
Assert.notNull(taskScheduler, "TaskScheduler must not be null");
this.taskScheduler = taskScheduler;
}
/**
* Set the {@link TaskScheduler} to register scheduled tasks with, or a
* {@link java.util.concurrent.ScheduledExecutorService} to be wrapped as a
* {@code TaskScheduler}.
*/
public void setScheduler(@Nullable Object scheduler) {
if (scheduler == null) {
this.taskScheduler = null;
}
else if (scheduler instanceof TaskScheduler) {
this.taskScheduler = (TaskScheduler) scheduler;
}
else if (scheduler instanceof ScheduledExecutorService) {
this.taskScheduler = new ConcurrentTaskScheduler(((ScheduledExecutorService) scheduler));
}
else {
throw new IllegalArgumentException("Unsupported scheduler type: " + scheduler.getClass());
}
}
/**
* Return the {@link TaskScheduler} instance for this registrar (may be {@code null}).
*/
@Nullable
public TaskScheduler getScheduler() {
return this.taskScheduler;
}
/**
* Specify triggered tasks as a Map of Runnables (the tasks) and Trigger objects
* (typically custom implementations of the {@link Trigger} interface).
*/
public void setTriggerTasks(Map<Runnable, Trigger> triggerTasks) {
this.triggerTasks = new ArrayList<>();
triggerTasks.forEach((task, trigger) -> addTriggerTask(new TriggerTask(task, trigger)));
}
/**
* Specify triggered tasks as a list of {@link TriggerTask} objects. Primarily used
* by {@code <task:*>} namespace parsing.
* @since 3.2
* @see ScheduledTasksBeanDefinitionParser
*/
public void setTriggerTasksList(List<TriggerTask> triggerTasks) {
this.triggerTasks = triggerTasks;
}
/**
* Get the trigger tasks as an unmodifiable list of {@link TriggerTask} objects.
* @return the list of tasks (never {@code null})
* @since 4.2
*/
public List<TriggerTask> getTriggerTaskList() {
return (this.triggerTasks != null? Collections.unmodifiableList(this.triggerTasks) :
Collections.emptyList());
}
/**
* Specify triggered tasks as a Map of Runnables (the tasks) and cron expressions.
* @see CronTrigger
*/
public void setCronTasks(Map<Runnable, String> cronTasks) {
this.cronTasks = new ArrayList<>();
cronTasks.forEach(this::addCronTask);
}
/**
* Specify triggered tasks as a list of {@link CronTask} objects. Primarily used by
* {@code <task:*>} namespace parsing.
* @since 3.2
* @see ScheduledTasksBeanDefinitionParser
*/
public void setCronTasksList(List<CronTask> cronTasks) {
this.cronTasks = cronTasks;
}
/**
* Get the cron tasks as an unmodifiable list of {@link CronTask} objects.
* @return the list of tasks (never {@code null})
* @since 4.2
*/
public List<CronTask> getCronTaskList() {
return (this.cronTasks != null ? Collections.unmodifiableList(this.cronTasks) :
Collections.emptyList());
}
/**
* Specify triggered tasks as a Map of Runnables (the tasks) and fixed-rate values.
* @see TaskScheduler#scheduleAtFixedRate(Runnable, long)
*/
public void setFixedRateTasks(Map<Runnable, Long> fixedRateTasks) {
this.fixedRateTasks = new ArrayList<>();
fixedRateTasks.forEach(this::addFixedRateTask);
}
/**
* Specify fixed-rate tasks as a list of {@link IntervalTask} objects. Primarily used
* by {@code <task:*>} namespace parsing.
* @since 3.2
* @see ScheduledTasksBeanDefinitionParser
*/
public void setFixedRateTasksList(List<IntervalTask> fixedRateTasks) {
this.fixedRateTasks = fixedRateTasks;
}
/**
* Get the fixed-rate tasks as an unmodifiable list of {@link IntervalTask} objects.
* @return the list of tasks (never {@code null})
* @since 4.2
*/
public List<IntervalTask> getFixedRateTaskList() {
return (this.fixedRateTasks != null ? Collections.unmodifiableList(this.fixedRateTasks) :
Collections.emptyList());
}
/**
* Specify triggered tasks as a Map of Runnables (the tasks) and fixed-delay values.
* @see TaskScheduler#scheduleWithFixedDelay(Runnable, long)
*/
public void setFixedDelayTasks(Map<Runnable, Long> fixedDelayTasks) {
this.fixedDelayTasks = new ArrayList<>();
fixedDelayTasks.forEach(this::addFixedDelayTask);
}
/**
* Specify fixed-delay tasks as a list of {@link IntervalTask} objects. Primarily used
* by {@code <task:*>} namespace parsing.
* @since 3.2
* @see ScheduledTasksBeanDefinitionParser
*/
public void setFixedDelayTasksList(List<IntervalTask> fixedDelayTasks) {
this.fixedDelayTasks = fixedDelayTasks;
}
/**
* Get the fixed-delay tasks as an unmodifiable list of {@link IntervalTask} objects.
* @return the list of tasks (never {@code null})
* @since 4.2
*/
public List<IntervalTask> getFixedDelayTaskList() {
return (this.fixedDelayTasks != null ? Collections.unmodifiableList(this.fixedDelayTasks) :
Collections.emptyList());
}
/**
* Add a Runnable task to be triggered per the given {@link Trigger}.
* @see TaskScheduler#scheduleAtFixedRate(Runnable, long)
*/
public void addTriggerTask(Runnable task, Trigger trigger) {
addTriggerTask(new TriggerTask(task, trigger));
}
/**
* Add a {@code TriggerTask}.
* @since 3.2
* @see TaskScheduler#scheduleAtFixedRate(Runnable, long)
*/
public void addTriggerTask(TriggerTask task) {
if (this.triggerTasks == null) {
this.triggerTasks = new ArrayList<>();
}
this.triggerTasks.add(task);
}
/**
* Add a {@link Runnable} task to be triggered per the given cron {@code expression}.
* <p>As of Spring Framework 5.2, this method will not register the task if the
* {@code expression} is equal to {@link #CRON_DISABLED}.
*/
public void addCronTask(Runnable task, String expression) {
if (!CRON_DISABLED.equals(expression)) {
addCronTask(new CronTask(task, expression));
}
}
/**
* Add a {@link CronTask}.
* @since 3.2
*/
public void addCronTask(CronTask task) {
if (this.cronTasks == null) {
this.cronTasks = new ArrayList<>();
}
this.cronTasks.add(task);
}
/**
* Add a {@code Runnable} task to be triggered at the given fixed-rate interval.
* @see TaskScheduler#scheduleAtFixedRate(Runnable, long)
*/
public void addFixedRateTask(Runnable task, long interval) {
addFixedRateTask(new IntervalTask(task, interval, 0));
}
/**
* Add a fixed-rate {@link IntervalTask}.
* @since 3.2
* @see TaskScheduler#scheduleAtFixedRate(Runnable, long)
*/
public void addFixedRateTask(IntervalTask task) {
if (this.fixedRateTasks == null) {
this.fixedRateTasks = new ArrayList<>();
}
this.fixedRateTasks.add(task);
}
/**
* Add a Runnable task to be triggered with the given fixed delay.
* @see TaskScheduler#scheduleWithFixedDelay(Runnable, long)
*/
public void addFixedDelayTask(Runnable task, long delay) {
addFixedDelayTask(new IntervalTask(task, delay, 0));
}
/**
* Add a fixed-delay {@link IntervalTask}.
* @since 3.2
* @see TaskScheduler#scheduleWithFixedDelay(Runnable, long)
*/
public void addFixedDelayTask(IntervalTask task) {
if (this.fixedDelayTasks == null) {
this.fixedDelayTasks = new ArrayList<>();
}
this.fixedDelayTasks.add(task);
}
/**
* Return whether this {@code ScheduledTaskRegistrar} has any tasks registered.
* @since 3.2
*/
public boolean hasTasks() {
return (!CollectionUtils.isEmpty(this.triggerTasks) ||
!CollectionUtils.isEmpty(this.cronTasks) ||
!CollectionUtils.isEmpty(this.fixedRateTasks) ||
!CollectionUtils.isEmpty(this.fixedDelayTasks));
}
/**
* Calls {@link #scheduleTasks()} at bean construction time.
*/
@Override
public void afterPropertiesSet() {
scheduleTasks();
}
/**
* Schedule all registered tasks against the underlying
* {@linkplain #setTaskScheduler(TaskScheduler) task scheduler}.
*/
@SuppressWarnings("deprecation")
protected void scheduleTasks() {
if (this.taskScheduler == null) {
this.localExecutor = Executors.newSingleThreadScheduledExecutor();
this.taskScheduler = new ConcurrentTaskScheduler(this.localExecutor);
}
if (this.triggerTasks != null) {
for (TriggerTask task : this.triggerTasks) {
addScheduledTask(scheduleTriggerTask(task));
}
}
if (this.cronTasks != null) {
for (CronTask task : this.cronTasks) {
addScheduledTask(scheduleCronTask(task));
}
}
if (this.fixedRateTasks != null) {
for (IntervalTask task : this.fixedRateTasks) {
addScheduledTask(scheduleFixedRateTask(task));
}
}
if (this.fixedDelayTasks != null) {
for (IntervalTask task : this.fixedDelayTasks) {
addScheduledTask(scheduleFixedDelayTask(task));
}
}
}
private void addScheduledTask(@Nullable ScheduledTask task) {
if (task != null) {
this.scheduledTasks.add(task);
}
}
/**
* Schedule the specified trigger task, either right away if possible
* or on initialization of the scheduler.
* @return a handle to the scheduled task, allowing to cancel it
* @since 4.3
*/
@Nullable
public ScheduledTask scheduleTriggerTask(TriggerTask task) {
ScheduledTask scheduledTask = this.unresolvedTasks.remove(task);
boolean newTask = false;
if (scheduledTask == null) {
scheduledTask = new ScheduledTask(task);
newTask = true;
}
if (this.taskScheduler != null) {
scheduledTask.future = this.taskScheduler.schedule(task.getRunnable(), task.getTrigger());
}
else {
addTriggerTask(task);
this.unresolvedTasks.put(task, scheduledTask);
}
return (newTask ? scheduledTask : null);
}
/**
* Schedule the specified cron task, either right away if possible
* or on initialization of the scheduler.
* @return a handle to the scheduled task, allowing to cancel it
* (or {@code null} if processing a previously registered task)
* @since 4.3
*/
@Nullable
public ScheduledTask scheduleCronTask(CronTask task) {
ScheduledTask scheduledTask = this.unresolvedTasks.remove(task);
boolean newTask = false;
if (scheduledTask == null) {
scheduledTask = new ScheduledTask(task);
newTask = true;
}
if (this.taskScheduler != null) {
scheduledTask.future = this.taskScheduler.schedule(task.getRunnable(), task.getTrigger());
}
else {
addCronTask(task);
this.unresolvedTasks.put(task, scheduledTask);
}
return (newTask ? scheduledTask : null);
}
/**
* Schedule the specified fixed-rate task, either right away if possible
* or on initialization of the scheduler.
* @return a handle to the scheduled task, allowing to cancel it
* (or {@code null} if processing a previously registered task)
* @since 4.3
* @deprecated as of 5.0.2, in favor of {@link #scheduleFixedRateTask(FixedRateTask)}
*/
@Deprecated
@Nullable
public ScheduledTask scheduleFixedRateTask(IntervalTask task) {
FixedRateTask taskToUse = (task instanceof FixedRateTask ? (FixedRateTask) task :
new FixedRateTask(task.getRunnable(), task.getInterval(), task.getInitialDelay()));
return scheduleFixedRateTask(taskToUse);
}
/**
* Schedule the specified fixed-rate task, either right away if possible
* or on initialization of the scheduler.
* @return a handle to the scheduled task, allowing to cancel it
* (or {@code null} if processing a previously registered task)
* @since 5.0.2
*/
@Nullable
public ScheduledTask scheduleFixedRateTask(FixedRateTask task) {
ScheduledTask scheduledTask = this.unresolvedTasks.remove(task);
boolean newTask = false;
if (scheduledTask == null) {
scheduledTask = new ScheduledTask(task);
newTask = true;
}
if (this.taskScheduler != null) {
if (task.getInitialDelay() > 0) {
Date startTime = new Date(this.taskScheduler.getClock().millis() + task.getInitialDelay());
scheduledTask.future =
this.taskScheduler.scheduleAtFixedRate(task.getRunnable(), startTime, task.getInterval());
}
else {
scheduledTask.future =
this.taskScheduler.scheduleAtFixedRate(task.getRunnable(), task.getInterval());
}
}
else {
addFixedRateTask(task);
this.unresolvedTasks.put(task, scheduledTask);
}
return (newTask ? scheduledTask : null);
}
/**
* Schedule the specified fixed-delay task, either right away if possible
* or on initialization of the scheduler.
* @return a handle to the scheduled task, allowing to cancel it
* (or {@code null} if processing a previously registered task)
* @since 4.3
* @deprecated as of 5.0.2, in favor of {@link #scheduleFixedDelayTask(FixedDelayTask)}
*/
@Deprecated
@Nullable
public ScheduledTask scheduleFixedDelayTask(IntervalTask task) {
FixedDelayTask taskToUse = (task instanceof FixedDelayTask ? (FixedDelayTask) task :
new FixedDelayTask(task.getRunnable(), task.getInterval(), task.getInitialDelay()));
return scheduleFixedDelayTask(taskToUse);
}
/**
* Schedule the specified fixed-delay task, either right away if possible
* or on initialization of the scheduler.
* @return a handle to the scheduled task, allowing to cancel it
* (or {@code null} if processing a previously registered task)
* @since 5.0.2
*/
@Nullable
public ScheduledTask scheduleFixedDelayTask(FixedDelayTask task) {
ScheduledTask scheduledTask = this.unresolvedTasks.remove(task);
boolean newTask = false;
if (scheduledTask == null) {
scheduledTask = new ScheduledTask(task);
newTask = true;
}
if (this.taskScheduler != null) {
if (task.getInitialDelay() > 0) {
Date startTime = new Date(this.taskScheduler.getClock().millis() + task.getInitialDelay());
scheduledTask.future =
this.taskScheduler.scheduleWithFixedDelay(task.getRunnable(), startTime, task.getInterval());
}
else {
scheduledTask.future =
this.taskScheduler.scheduleWithFixedDelay(task.getRunnable(), task.getInterval());
}
}
else {
addFixedDelayTask(task);
this.unresolvedTasks.put(task, scheduledTask);
}
return (newTask ? scheduledTask : null);
}
/**
* Return all locally registered tasks that have been scheduled by this registrar.
* @since 5.0.2
* @see #addTriggerTask
* @see #addCronTask
* @see #addFixedRateTask
* @see #addFixedDelayTask
*/
@Override
public Set<ScheduledTask> getScheduledTasks() {
return Collections.unmodifiableSet(this.scheduledTasks);
}
@Override
public void destroy() {
for (ScheduledTask task : this.scheduledTasks) {
task.cancel();
}
if (this.localExecutor != null) {
this.localExecutor.shutdownNow();
}
}
}