Spring开启方法异步执行详解编程语言

public @interface EnableAsync { Class ? extends Annotation annotation() default Annotation.class; boolean proxyTargetClass() default false; AdviceMode mode() default AdviceMode.PROXY; int order() default Ordered.LOWEST_PRECEDENCE; }

@EnableAsync注解即开启Spring对方法异步执行的能力，[email protected]

@Configuration 

@EnableAsync 

public class AppConfig { 

}

 

也可以自定义线程池

@Configuration 

@EnableAsync 

public class AppConfig implements AsyncConfigurer { 

 @Override 

 public Executor getAsyncExecutor() { 

 ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor(); 

 executor.setCorePoolSize(7); 

 executor.setMaxPoolSize(42); 

 executor.setQueueCapacity(11); 

 executor.setThreadNamePrefix("MyExecutor-"); 

 executor.initialize(); 

 return executor; 

 @Override 

 public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() { 

 return MyAsyncUncaughtExceptionHandler(); 

}

@Async

@Target({ElementType.METHOD, ElementType.TYPE}) 

@Retention(RetentionPolicy.RUNTIME) 

@Documented 

public @interface Async { 

 String value() default ""; 

}

 

[email protected]，下面是一个没有返回值，一个带有返回值的异步调用的示例。

@Component 

public class AsyncTask { 

 @Async 

 public void task1() { 

 try { 

 Thread.sleep(3000); 

 } catch (InterruptedException e) { 

 e.printStackTrace(); 

 @Async 

 public Future String task2() { 

 try { 

 Thread.sleep(3000); 

 } catch (InterruptedException e) { 

 e.printStackTrace(); 

 return new AsyncResult String ("javastack"); 

 }
 

}

 

测试代码

 

@RunWith(SpringRunner.class) 

@SpringBootTest 

public class AsyncTest { 

 private final static Logger log = LoggerFactory.getLogger(AsyncTest.class); 

 @Autowired 

 private AsyncTask asyncTask; 

 @Test 

 public void testTask1(){ 

 log.info("start"); 

 asyncTask.task1(); 

 log.info("finish"); 

 @Test 

 public void testTask2() { 

 log.info("start"); 

 Future String future = asyncTask.task2(); 

 while (true) { 

 if (future.isDone()) { 

 try { 

 log.info("result is " + future.get()); 

 } catch (Exception e) { 

 e.printStackTrace(); 

 break; 

 log.info("finish"); 

}

 

 

1、使用注意

@Async只能使用到被代理的对象方法上，即代理类的入口方法处，且方法必须是public的。

2、事务处理机制

[email protected]@Transaction事务注解在同一个方法上同时使用，不然事务注解将无效。

要使用事务，需要把事务注解提取到方法里面的子方法上。

原创文章，作者：Maggie-Hunter，如若转载，请注明出处：https://blog.ytso.com/16524.html

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