Question

@Override
@Async
public void asyncExceptionTest() {
    int i=1/0;
}

How can I log this using Spring Async framework without having to put try catch around every async method? It doesn’t seem to pass to the DefaultUncaughtExceptionHandler like normal.

Answer 1

@Async methods can be configured with a custom Executor to log any thrown exceptions.

The following code implements this pattern. Any method tagged with @Async will use the Executor returned by the method public Executor getAsyncExecutor(). This returns the HandlingExecutor which takes care of all logging (in this case it just prints the word “CAUGHT!” but you can replace with logging.

@Configuration
@EnableAsync
public class ExampleConfig implements AsyncConfigurer {
    @Bean
    public Runnable testExec() {
        return new TestExec();
    }

    @Override
    public Executor getAsyncExecutor() {
        final ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(7);
        executor.setMaxPoolSize(42);
        executor.setQueueCapacity(11);
        executor.setThreadNamePrefix("MyExecutor-");
        executor.initialize();
        return new HandlingExecutor(executor);
    }
}

public class HandlingExecutor implements AsyncTaskExecutor {
    private AsyncTaskExecutor executor;

    public HandlingExecutor(AsyncTaskExecutor executor) {
        this.executor = executor;
    }

    @Override
    public void execute(Runnable task) {
        executor.execute(task);
    }

    @Override
    public void execute(Runnable task, long startTimeout) {
        executor.execute(createWrappedRunnable(task), startTimeout);
    }

    @Override
    public Future<?> submit(Runnable task) {
        return executor.submit(createWrappedRunnable(task));
    }

    @Override
    public <T> Future<T> submit(final Callable<T> task) {
        return executor.submit(createCallable(task));
    }

    private <T> Callable<T> createCallable(final Callable<T> task) {
        return new Callable<T>() {
            @Override
            public T call() throws Exception {
                try {
                    return task.call();
                } catch (Exception e) {
                    handle(e);
                    throw e;
                }
            }
        };
    }

    private Runnable createWrappedRunnable(final Runnable task) {
        return new Runnable() {
            @Override
            public void run() {
                try {
                    task.run();
                } catch (Exception e) {
                    handle(e);
                }
            }
        };
    }

    private void handle(Exception e) {
        System.out.println("CAUGHT!");
    }
}