Spring Boot @Async 异步任务执行

内容预览:
  • 1、任务执行和调度 Spring用TaskExecutor和TaskScheduler接口提供了异步...~
  • SimpleThreadPoolTaskExecutor  这种实现实际上是Quartz的SimpleTh...~
  • In other words, the caller will return immediately upon invocation ...~

1、任务执行和调度

SpringTaskExecutorTaskScheduler接口提供了异步执行和调度任务的抽象。

SpringTaskExecutorjava.util.concurrent.Executor接口时一样的,这个接口只有一个方法execute(Runnable task)

1.1、TaskExecutor类型

Spring已经内置了许多TaskExecutor的实现,你没有必要自己去实现:

  • SimpleAsyncTaskExecutor  这种实现不会重用任何线程,每次调用都会创建一个新的线程。
  • SyncTaskExecutor  这种实现不会异步的执行
  • ConcurrentTaskExecutor  这种实现是java.util.concurrent.Executor的一个adapter
  • SimpleThreadPoolTaskExecutor  这种实现实际上是Quartz的SimpleThreadPool的一个子类,它监听Spring的声明周期回调。
  • ThreadPoolTaskExecutor  这是最常用最通用的一种实现。它包含了java.util.concurrent.ThreadPoolExecutor的属性,并且用TaskExecutor进行包装。

1.2、注解支持调度和异步执行

To enable support for @Scheduled and @Async annotations add @EnableScheduling and @EnableAsync to one of your @Configuration classes:

@Configuration
@EnableAsync
@EnableScheduling
public class AppConfig {
}

特别注意

The default advice mode for processing @Async annotations is “proxy” which allows for interception of calls through the proxy only; local calls within the same class cannot get intercepted that way. For a more advanced mode of interception, consider switching to “aspectj” mode in combination with compile-time or load-time weaving.

默认是用代理去处理@Async的,因此,相同类中的方法调用带@Async的方法是无法异步的,这种情况仍然是同步。

举个例子:下面这种,在外部直接调用sayHi()是可以异步执行的,而调用sayHello()时sayHi()仍然是同步执行

public class A {

public void sayHello() {
sayHi();
}

@Async
public void sayHi() {

}

}

1.3、@Async注解

在方法上加@Async注解表示这是一个异步调用。换句话说,方法的调用者会立即得到返回,并且实际的方法执行是想Spring的TaskExecutor提交了一个任务。

In other words, the caller will return immediately upon invocation and the actual execution of the method will occur in a task that has been submitted to a Spring TaskExecutor.

@Async
void doSomething() {
// this will be executed asynchronously
}

@Async
void doSomething(String s) {
// this will be executed asynchronously
}

@Async
Future
<String> returnSomething(int i) {
// this will be executed asynchronously
}

注意:

@Async methods may not only declare a regular java.util.concurrent.Future return type but also Spring’s org.springframework.util.concurrent.ListenableFuture or, as of Spring 4.2, JDK 8’s java.util.concurrent.CompletableFuture: for richer interaction with the asynchronous task and for immediate composition with further processing steps.

1.4、@Async限定Executor

默认情况下,当在方法上加@Async注解时,将会使用一个支持注解驱动的Executor。然而,@Async注解的value值可以指定一个别的Executor

@Async("otherExecutor")
void doSomething(String s) {
// this will be executed asynchronously by "otherExecutor"
}

这里,otherExecutor是Spring容器中任意Executor bean的名字。

1.5、@Async异常管理

当一个@Async方法有一个Future类型的返回值时,就很容易管理在调Future的get()方法获取任务的执行结果时抛出的异常。如果返回类型是void,那么异常是不会被捕获到的。

public class MyAsyncUncaughtExceptionHandler implements AsyncUncaughtExceptionHandler {

@Override
public void handleUncaughtException(Throwable ex, Method method, Object... params) {
// handle exception
}
}

 2、线程池配置

 1
3 import org.springframework.context.annotation.Bean;
4 import org.springframework.context.annotation.Configuration;
5 import org.springframework.scheduling.annotation.EnableAsync;
6 import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
7
8 @Configuration
9 @EnableAsync
10 public class TaskExecutorConfig {
11
12 private Integer corePoolSize = 30;
13
14 private Integer maxPoolSize = 50;
15
16 private Integer keepAliveSeconds = 300;
17
18 // private Integer queueCapacity = 2000;
19
20 @Bean("myThreadPoolTaskExecutor")
21 public ThreadPoolTaskExecutor myThreadPoolTaskExecutor() {
22 ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
23 executor.setCorePoolSize(corePoolSize);
24 executor.setMaxPoolSize(maxPoolSize);
25 executor.setKeepAliveSeconds(keepAliveSeconds);
26 // executor.setQueueCapacity(queueCapacity);
27 executor.setWaitForTasksToCompleteOnShutdown(true);
28 executor.initialize();
29 return executor;
30 }
31
32 }

调用

 1     @Async("myThreadPoolTaskExecutor")
2 @Override
3 public void present(CouponPresentLogEntity entity) {
4 try {
5 CouponBaseResponse rst = couponSendRpcService.send(entity.getUserId(), entity.getCouponBatchKey(), "1", entity.getVendorId());
6 if (null != rst && rst.isSuccess()) {
7 entity.setStatus(PresentStatusEnum.SUCCESS.getType());
8 }else {
9 String reason = (null == rst) ? "响应异常" : rst.getMsg();
10 entity.setFailureReason(reason);
11 entity.setStatus(PresentStatusEnum.FAILURE.getType());
12 }
13 }catch (Exception ex) {
14 log.error(ex.getMessage(), ex);
15 entity.setFailureReason(ex.getMessage());
16 entity.setStatus(PresentStatusEnum.FAILURE.getType());
17 }
18 couponPresentLogDao.update(entity);
19 }

结果

[INFO ] 2018-05-09 16:27:39.887 [myThreadPoolTaskExecutor-1] [com.ourhours.coupon.rpc.dubbo.ReceiveLogFilter] - receive method-name:send; arguments:[10046031,"4d7cc32f8f7e4b00bca56f6bf4b3b658","1",10001]
[INFO ]
2018-05-09 16:27:39.889 [myThreadPoolTaskExecutor-2] [com.ourhours.coupon.rpc.dubbo.ReceiveLogFilter] - receive method-name:send; arguments:[10046031,"4d7cc32f8f7e4b00bca56f6bf4b3b658","1",10001]

 

 

 参考:

Spring Framework Reference Documentation 4.3.17.RELEASE

 

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