spring-boot 方法異步調用，自定義線程池配置使用

一、在主類中添加@EnableAsync註解：

@SpringBootApplication
@EnableScheduling
@EnableAsync
public class MySpringBootApplication {
	private static Logger logger = LoggerFactory.getLogger(MySpringBootApplication.class);
	
	public static void main(String[] args) {
		SpringApplication.run(MySpringBootApplication.class, args);
		logger.info("My Spring Boot Application Started");
	}

二、建立一個AsyncTask類，在裏面添加兩個用@Async註解的task：

@Component
public class AsyncTask {
	protected final Logger logger = LoggerFactory.getLogger(this.getClass());
	
	@Async
	public Future<String> doTask1() throws InterruptedException{
		logger.info("Task1 started.");
		long start = System.currentTimeMillis();
        Thread.sleep(5000);
        long end = System.currentTimeMillis();
        
        logger.info("Task1 finished, time elapsed: {} ms.", end-start);
        
        return new AsyncResult<>("Task1 accomplished!");
	}
	
	@Async
	public Future<String> doTask2() throws InterruptedException{
		logger.info("Task2 started.");
		long start = System.currentTimeMillis();
        Thread.sleep(3000);
        long end = System.currentTimeMillis();
        
        logger.info("Task2 finished, time elapsed: {} ms.", end-start);
        
        return new AsyncResult<>("Task2 accomplished!");
	}
}

三、萬事俱備，開始測試：

public class TaskTests extends BasicUtClass{
	@Autowired
	private AsyncTask asyncTask;
	
	
	@Test
	public void AsyncTaskTest() throws InterruptedException, ExecutionException {
		Future<String> task1 = asyncTask.doTask1();
		Future<String> task2 = asyncTask.doTask2();
		
		while(true) {
			if(task1.isDone() && task2.isDone()) {
				logger.info("Task1 result: {}", task1.get());
				logger.info("Task2 result: {}", task2.get());
				break;
			}
			Thread.sleep(1000);
		}
		
		logger.info("All tasks finished.");
	}
}

測試結果：

2016-12-13 11:12:24,850:INFO main (AsyncExecutionAspectSupport.java:245) - No TaskExecutor bean found for async processing
2016-12-13 11:12:24,864:INFO SimpleAsyncTaskExecutor-1 (AsyncTask.java:22) - Task1 started.
2016-12-13 11:12:24,865:INFO SimpleAsyncTaskExecutor-2 (AsyncTask.java:34) - Task2 started.
2016-12-13 11:12:27,869:INFO SimpleAsyncTaskExecutor-2 (AsyncTask.java:39) - Task2 finished, time elapsed: 3001 ms.
2016-12-13 11:12:29,866:INFO SimpleAsyncTaskExecutor-1 (AsyncTask.java:27) - Task1 finished, time elapsed: 5001 ms.
2016-12-13 11:12:30,853:INFO main (TaskTests.java:23) - Task1 result: Task1 accomplished!
2016-12-13 11:12:30,853:INFO main (TaskTests.java:24) - Task2 result: Task2 accomplished!
2016-12-13 11:12:30,854:INFO main (TaskTests.java:30) - All tasks finished.

能夠看到，沒有自定義的Executor，因此使用缺省的TaskExecutor 。

 

前面是最簡單的使用方法。若是想使用自定義的Executor，能夠按照以下幾步來：

一、新建一個Executor配置類，順便把@EnableAsync註解搬到這裏來：

@Configuration
@EnableAsync
public class ExecutorConfig {

	/** Set the ThreadPoolExecutor's core pool size. */
	private int corePoolSize = 10;
	/** Set the ThreadPoolExecutor's maximum pool size. */
	private int maxPoolSize = 200;
	/** Set the capacity for the ThreadPoolExecutor's BlockingQueue. */
	private int queueCapacity = 10;

	@Bean
	public Executor mySimpleAsync() {
		ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
		executor.setCorePoolSize(corePoolSize);
		executor.setMaxPoolSize(maxPoolSize);
		executor.setQueueCapacity(queueCapacity);
		executor.setThreadNamePrefix("MySimpleExecutor-");
		executor.initialize();
		return executor;
	}
	
	@Bean
	public Executor myAsync() {
		ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
		executor.setCorePoolSize(corePoolSize);
		executor.setMaxPoolSize(maxPoolSize);
		executor.setQueueCapacity(queueCapacity);
		executor.setThreadNamePrefix("MyExecutor-");

		// rejection-policy：當pool已經達到max size的時候，如何處理新任務
		// CALLER_RUNS：不在新線程中執行任務，而是有調用者所在的線程來執行
		executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
		executor.initialize();
		return executor;
	}
}

這裏定義了兩個不一樣的Executor，第二個從新設置了pool已經達到max size時候的處理方法；同時指定了線程名字的前綴。

二、自定義Executor的使用：

@Component
public class AsyncTask {
	protected final Logger logger = LoggerFactory.getLogger(this.getClass());
	
	@Async("mySimpleAsync")
	public Future<String> doTask1() throws InterruptedException{
		logger.info("Task1 started.");
		long start = System.currentTimeMillis();
        Thread.sleep(5000);
        long end = System.currentTimeMillis();
        
        logger.info("Task1 finished, time elapsed: {} ms.", end-start);
        
        return new AsyncResult<>("Task1 accomplished!");
	}
	
	@Async("myAsync")
	public Future<String> doTask2() throws InterruptedException{
		logger.info("Task2 started.");
		long start = System.currentTimeMillis();
        Thread.sleep(3000);
        long end = System.currentTimeMillis();
        
        logger.info("Task2 finished, time elapsed: {} ms.", end-start);
        
        return new AsyncResult<>("Task2 accomplished!");
	}
}

就是把上面自定義Executor的類名，放進@Async註解中。

三、（測試用例不變）測試結果：

2016-12-13 10:57:11,998:INFO MySimpleExecutor-1 (AsyncTask.java:22) - Task1 started.
2016-12-13 10:57:12,001:INFO MyExecutor-1 (AsyncTask.java:34) - Task2 started.
2016-12-13 10:57:15,007:INFO MyExecutor-1 (AsyncTask.java:39) - Task2 finished, time elapsed: 3000 ms.
2016-12-13 10:57:16,999:INFO MySimpleExecutor-1 (AsyncTask.java:27) - Task1 finished, time elapsed: 5001 ms.
2016-12-13 10:57:17,994:INFO main (TaskTests.java:23) - Task1 result: Task1 accomplished!
2016-12-13 10:57:17,994:INFO main (TaskTests.java:24) - Task2 result: Task2 accomplished!
2016-12-13 10:57:17,994:INFO main (TaskTests.java:30) - All tasks finished.
2016-12-13 10:57:18,064 Thread-3 WARN Unable to register Log4j shutdown hook because JVM is shutting down. Using SimpleLogger

可見，線程名字的前綴變了，兩個task使用了不一樣的線程池了。

參考博客：http://blog.csdn.net/clementad/article/details/53607311