spring boot 异步执行（@EnableAsync，@Async）

过去使用spring3.x，很可能这样写一段代码执行一个异步的任务：

@Autowired ThreadPoolTaskExecutor executor; public void dosomething() { executor.execute(new Runnable() { @Override public void run() { } }); }

现在看看spring boot中是如何处理的： 1. 首先通过@EnableAsync开启异步执行的功能，这可以放在springboot主类上，或者放在我们的配置类上。 2. 配置自定义的线程池（如果不自定义的话，springboot会提供默认的）。 我这边是把@EnableAsync放在了自定义线程池的配置上。

@Configuration @EnableAsync public class ExecutorConfig { @Bean public Executor firstExecutor() { ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor(); executor.setCorePoolSize(10); executor.setMaxPoolSize(20); executor.setQueueCapacity(10); executor.setThreadNamePrefix("firstExecutor-"); executor.initialize(); return executor; } @Bean public Executor secondExecutor() { ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor(); executor.setCorePoolSize(20); executor.setMaxPoolSize(100); executor.setQueueCapacity(20); executor.setThreadNamePrefix("secondExecutor-"); executor.initialize(); return executor; } }

这边配置了两个线程池，后面会知道如何指定使用的线程池。 注：一般生产中线程池参数往往会从配置文件中获取，获取方式可以看这篇文章： spring boot 通过@Value，@ConfigurationProperties获取配置 3. 配置执行类

@Component public class Task { @Async("firstExecutor") public Future<String> exec1() throws InterruptedException { System.out.println(Thread.currentThread().getName() + " exec1 开始:" + new Date()); Thread.sleep(2000L); System.out.println(Thread.currentThread().getName() + " exec1 结束:" + new Date()); return new AsyncResult<>("exec1"); } @Async("secondExecutor") public Future<String> exec2() throws InterruptedException { System.out.println(Thread.currentThread().getName() + " exec2 开始:" + new Date()); Thread.sleep(4000L); System.out.println(Thread.currentThread().getName() + " exec2 结束:" + new Date()); return new AsyncResult<>("exec2"); } @Async("secondExecutor") public Future<String> exec3() throws InterruptedException { System.out.println(Thread.currentThread().getName() + " exec3 开始:" + new Date()); Thread.sleep(4000L); System.out.println(Thread.currentThread().getName() + " exec3 结束:" + new Date()); return new AsyncResult<>("exec3"); } }

@Async: 注解的方法表示为异步执行的方法，值为指定的线程池，当只有一个自定义的线程池或使用默认线程池时，值可以省略。 4. 测试类

@RunWith(SpringRunner.class) @SpringBootTest public class ExecutorMynotesApplicationTests { @Autowired private Task task; @Test public void contextLoads() throws InterruptedException, ExecutionException { Future<String> future1 = task.exec1(); Future<String> future2 = task.exec2(); Future<String> future3 = task.exec3(); future1.get(); future2.get(); future3.get(); } }

执行结果：

secondExecutor-1 exec2 开始:Fri Sep 01 10:02:37 CST 2017 firstExecutor-1 exec1 开始:Fri Sep 01 10:02:37 CST 2017 secondExecutor-2 exec3 开始:Fri Sep 01 10:02:37 CST 2017 firstExecutor-1 exec1 结束:Fri Sep 01 10:02:39 CST 2017 secondExecutor-2 exec3 结束:Fri Sep 01 10:02:41 CST 2017 secondExecutor-1 exec2 结束:Fri Sep 01 10:02:41 CST 2017

代码