@Async的异常处理

方法一：配置AsyncUncaughtExceptionHandler（对于无返回值的方法）
通过AsyncConfigurer自定义线程池，以及异常处理。

@Configuration
@EnableAsync
public class SpringAsyncConfiguration implements AsyncConfigurer {
    private static final Logger logger = LoggerFactory.getLogger(getClass());
    @Bean
    @Override
    public Executor getAsyncExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(8);
        executor.setMaxPoolSize(16);
        executor.setQueueCapacity(64);
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        executor.setThreadNamePrefix("SpringAsyncThread-");

        return executor;
    }

    @Override
    public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
        return new SpringAsyncExceptionHandler();
    }

    class SpringAsyncExceptionHandler implements AsyncUncaughtExceptionHandler {
        @Override
        public void handleUncaughtException(Throwable throwable, Method method, Object... obj) {
            logger.error("Exception occurs in async method", throwable.getMessage());
        }
    }

}

方法二：通过AsyncResult捕获异常（对于有返回值的方法）
如果异步方法有返回值，那就应当返回AsyncResult类的对象，以便在调用处捕获异常。
因为AsyncResult是Future接口的子类，所以也可以通过future.get()获取返回值的时候捕获ExcecutionException。
异步方法：

@Service
public class AsyncService {

    @Async
    public AsyncResult<String> asyncMethodWithResult() {
        // do something（可能发生异常）

        return new AsyncResult("hello");
    }

}

public class Test {

    private Logger logger = LoggerFactory.getLogger(getClass());

    @Autowired
    AsyncService asyncService;

    public void test() {
        try {
            Future future = asyncService.asyncMethodWithResult();
            future.get();
        } catch (ExecutionException e) {
            logger.error("exception occurs", e);
        } catch (InterruptedException e) {
            logger.error("exception occurs", e);
        }
    }

}