You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
302 lines
12 KiB
302 lines
12 KiB
5 years ago
|
# Spring 定时任务
|
||
|
|
- Author: [HuiFer](https://github.com/huifer)
|
||
|
|
- 源码阅读仓库: [SourceHot-spring](https://github.com/SourceHot/spring-framework-read)
|
||
|
|
|
||
|
|
## EnableScheduling
|
||
|
|
- 首先关注的类为启动定时任务的注解`@EnableScheduling`
|
||
|
|
```java
|
||
|
|
@Target(ElementType.TYPE)
|
||
|
|
@Retention(RetentionPolicy.RUNTIME)
|
||
|
|
@Import(SchedulingConfiguration.class)
|
||
|
|
@Documented
|
||
|
|
public @interface EnableScheduling {
|
||
|
|
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
## SchedulingConfiguration
|
||
|
|
- 注册定时任务相关信息
|
||
|
|
```java
|
||
|
|
@Configuration
|
||
|
|
@Role(BeanDefinition.ROLE_INFRASTRUCTURE)
|
||
|
|
public class SchedulingConfiguration {
|
||
|
|
|
||
|
|
/**
|
||
|
|
* 开启定时任务
|
||
|
|
* @return
|
||
|
|
*/
|
||
|
|
@Bean(name = TaskManagementConfigUtils.SCHEDULED_ANNOTATION_PROCESSOR_BEAN_NAME)
|
||
|
|
@Role(BeanDefinition.ROLE_INFRASTRUCTURE)
|
||
|
|
public ScheduledAnnotationBeanPostProcessor scheduledAnnotationProcessor() {
|
||
|
|
// 注册 ScheduledAnnotationBeanPostProcessor
|
||
|
|
return new ScheduledAnnotationBeanPostProcessor();
|
||
|
|
}
|
||
|
|
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
## ScheduledAnnotationBeanPostProcessor
|
||
|
|
- 关注application事件,以及spring生命周期相关的接口实现
|
||
|
|
```java
|
||
|
|
/**
|
||
|
|
* application 事件
|
||
|
|
* @param event the event to respond to
|
||
|
|
*/
|
||
|
|
@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).
|
||
|
|
// 注册定时任务
|
||
|
|
finishRegistration();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
```java
|
||
|
|
@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;
|
||
|
|
}
|
||
|
|
|
||
|
|
// 当前类
|
||
|
|
Class<?> targetClass = AopProxyUtils.ultimateTargetClass(bean);
|
||
|
|
if (!this.nonAnnotatedClasses.contains(targetClass)) {
|
||
|
|
// 方法扫描,存在 Scheduled、Schedules 注解的全部扫描
|
||
|
|
Map<Method, Set<Scheduled>> annotatedMethods = MethodIntrospector.selectMethods(targetClass,
|
||
|
|
(MethodIntrospector.MetadataLookup<Set<Scheduled>>) method -> {
|
||
|
|
|
||
|
|
Set<Scheduled> scheduledMethods = AnnotatedElementUtils.getMergedRepeatableAnnotations(
|
||
|
|
method, Scheduled.class, Schedules.class);
|
||
|
|
return (!scheduledMethods.isEmpty() ? scheduledMethods : 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, scheduledMethods) ->
|
||
|
|
// 处理 scheduled 相关信息
|
||
|
|
scheduledMethods.forEach(scheduled -> processScheduled(scheduled, method, bean)));
|
||
|
|
if (logger.isTraceEnabled()) {
|
||
|
|
logger.trace(annotatedMethods.size() + " @Scheduled methods processed on bean '" + beanName +
|
||
|
|
"': " + annotatedMethods);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return bean;
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
- 处理定时任务注解
|
||
|
|
```java
|
||
|
|
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
|
||
|
|
// 是否延迟执行
|
||
|
|
long initialDelay = scheduled.initialDelay();
|
||
|
|
// 延迟执行时间
|
||
|
|
String initialDelayString = scheduled.initialDelayString();
|
||
|
|
// 是否有延迟执行的时间
|
||
|
|
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 = parseDelayAsLong(initialDelayString);
|
||
|
|
}
|
||
|
|
catch (RuntimeException ex) {
|
||
|
|
throw new IllegalArgumentException(
|
||
|
|
"Invalid initialDelayString value \"" + initialDelayString + "\" - cannot parse into long");
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Check cron expression
|
||
|
|
// 获取cron表达式
|
||
|
|
String cron = scheduled.cron();
|
||
|
|
// cron表达式是否存在
|
||
|
|
if (StringUtils.hasText(cron)) {
|
||
|
|
// 获取时区
|
||
|
|
String zone = scheduled.zone();
|
||
|
|
if (this.embeddedValueResolver != null) {
|
||
|
|
// 字符串转换
|
||
|
|
cron = this.embeddedValueResolver.resolveStringValue(cron);
|
||
|
|
zone = this.embeddedValueResolver.resolveStringValue(zone);
|
||
|
|
}
|
||
|
|
if (StringUtils.hasLength(cron)) {
|
||
|
|
// cron 是否延迟
|
||
|
|
Assert.isTrue(initialDelay == -1, "'initialDelay' not supported for cron triggers");
|
||
|
|
processedSchedule = true;
|
||
|
|
if (!Scheduled.CRON_DISABLED.equals(cron)) {
|
||
|
|
TimeZone timeZone;
|
||
|
|
if (StringUtils.hasText(zone)) {
|
||
|
|
// 时区解析
|
||
|
|
timeZone = StringUtils.parseTimeZoneString(zone);
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
// 默认时区获取
|
||
|
|
timeZone = TimeZone.getDefault();
|
||
|
|
}
|
||
|
|
// 创建任务
|
||
|
|
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
|
||
|
|
// 获取间隔调用时间
|
||
|
|
long fixedDelay = scheduled.fixedDelay();
|
||
|
|
// 间隔时间>0
|
||
|
|
if (fixedDelay >= 0) {
|
||
|
|
Assert.isTrue(!processedSchedule, errorMessage);
|
||
|
|
processedSchedule = true;
|
||
|
|
// 创建任务,间隔时间定时任务
|
||
|
|
tasks.add(this.registrar.scheduleFixedDelayTask(new FixedDelayTask(runnable, fixedDelay, initialDelay)));
|
||
|
|
}
|
||
|
|
// 延迟时间
|
||
|
|
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 = parseDelayAsLong(fixedDelayString);
|
||
|
|
}
|
||
|
|
catch (RuntimeException ex) {
|
||
|
|
throw new IllegalArgumentException(
|
||
|
|
"Invalid fixedDelayString value \"" + fixedDelayString + "\" - cannot parse into long");
|
||
|
|
}
|
||
|
|
// 创建延迟时间任务
|
||
|
|
tasks.add(this.registrar.scheduleFixedDelayTask(new FixedDelayTask(runnable, fixedDelay, initialDelay)));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Check fixed rate
|
||
|
|
// 获取调用频率
|
||
|
|
long fixedRate = scheduled.fixedRate();
|
||
|
|
if (fixedRate >= 0) {
|
||
|
|
Assert.isTrue(!processedSchedule, errorMessage);
|
||
|
|
processedSchedule = true;
|
||
|
|
// 创建调用频率的定时任务
|
||
|
|
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 = parseDelayAsLong(fixedRateString);
|
||
|
|
}
|
||
|
|
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) {
|
||
|
|
// 定时任务注册
|
||
|
|
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());
|
||
|
|
}
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
|
||
|
|
## 定时任务
|
||
|
|
- CronTask
|
||
|
|
- cron定时任务
|
||
|
|
- FixedDelayTask
|
||
|
|
- 间隔时间的定时任务
|
||
|
|
- FixedRateTask
|
||
|
|
- 调用频率的定时任务
|
||
|
|
- ScheduledTask
|
||
|
|
- 定时任务对象
|
||
|
|
### cron 表达式解析
|
||
|
|
- `org.springframework.scheduling.support.CronSequenceGenerator.doParse`
|
||
|
|
```java
|
||
|
|
private void doParse(String[] fields) {
|
||
|
|
setNumberHits(this.seconds, fields[0], 0, 60);
|
||
|
|
setNumberHits(this.minutes, fields[1], 0, 60);
|
||
|
|
setNumberHits(this.hours, fields[2], 0, 24);
|
||
|
|
setDaysOfMonth(this.daysOfMonth, fields[3]);
|
||
|
|
setMonths(this.months, fields[4]);
|
||
|
|
setDays(this.daysOfWeek, replaceOrdinals(fields[5], "SUN,MON,TUE,WED,THU,FRI,SAT"), 8);
|
||
|
|
|
||
|
|
if (this.daysOfWeek.get(7)) {
|
||
|
|
// Sunday can be represented as 0 or 7
|
||
|
|
this.daysOfWeek.set(0);
|
||
|
|
this.daysOfWeek.clear(7);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
```
|
||
|
|
|
||
|
|
### 执行定时任务
|
||
|
|
- 这里以 CronTask 任务进行分析,其他定时任务同理
|
||
|
|
- `org.springframework.scheduling.config.ScheduledTaskRegistrar.scheduleCronTask`
|
||
|
|
```java
|
||
|
|
@Nullable
|
||
|
|
public ScheduledTask scheduleCronTask(CronTask task) {
|
||
|
|
// 从未执行的任务列表中删除,并且获取这个任务
|
||
|
|
ScheduledTask scheduledTask = this.unresolvedTasks.remove(task);
|
||
|
|
boolean newTask = false;
|
||
|
|
// 没有这个任务
|
||
|
|
if (scheduledTask == null) {
|
||
|
|
scheduledTask = new ScheduledTask(task);
|
||
|
|
newTask = true;
|
||
|
|
}
|
||
|
|
// 任务调度器是否为空
|
||
|
|
if (this.taskScheduler != null) {
|
||
|
|
|
||
|
|
scheduledTask.future = this.taskScheduler.schedule(task.getRunnable(), task.getTrigger());
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
// 添加到cron任务列表
|
||
|
|
addCronTask(task);
|
||
|
|
// 保存到没有执行的任务中
|
||
|
|
this.unresolvedTasks.put(task, scheduledTask);
|
||
|
|
}
|
||
|
|
return (newTask ? scheduledTask : null);
|
||
|
|
}
|
||
|
|
|
||
|
|
```
|