Question

将异步方法的Spring配置类设置为：

@Configuration
@EnableAsync(proxyTargetClass = true)
@EnableScheduling
public class AsyncConfiguration {

@Autowired
private ApplicationContext applicationContext;

@Bean
public ActivityMessageListener activityMessageListener() {
    return new ActivityMessageListener();
}
@Bean
public TaskExecutor defaultExecutor()
{
    ThreadPoolTaskExecutor threadPoolTaskExecutor = new ThreadPoolTaskExecutor();
    threadPoolTaskExecutor.setCorePoolSize(10);
    threadPoolTaskExecutor.setMaxPoolSize(10);
    threadPoolTaskExecutor.setQueueCapacity(Integer.MAX_VALUE);

    return threadPoolTaskExecutor;
}

我的所有@Async方法都按预期工作，但如果我将AsyncConfigurer实现到AsyncConfiguration以捕获实现getAsyncUncaughtExceptionHandler()方法的异常，那么我的bean不会被代理，所以方法@Async不会在池执行程序中运行。

这是非工作配置：

@Configuration
@EnableAsync(proxyTargetClass = true)
@EnableScheduling
public class AsyncConfiguration implements AsyncConfigurer {

@Autowired
private ApplicationContext applicationContext;

@Bean
public ActivityMessageListener activityMessageListener() {
    return new ActivityMessageListener();
}

@Override
public Executor getAsyncExecutor() {
    ThreadPoolTaskExecutor threadPoolTaskExecutor = new ThreadPoolTaskExecutor();
    threadPoolTaskExecutor.setCorePoolSize(10);
    threadPoolTaskExecutor.setMaxPoolSize(10);
    threadPoolTaskExecutor.setQueueCapacity(Integer.MAX_VALUE);

    return threadPoolTaskExecutor;
}

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

可能会发生什么？

我们正在使用这样的@Async：

public class ActivityMessageListener extends BaseMessageListener {

public static final String PARAM_USER_ID                = "userId";
public static final String PARAM_COMPANY_ID             = "companyId";
public static final String PARAM_CREATE_DATE            = "createDate";
public static final String PARAM_CLASS_NAME             = "className";
public static final String PARAM_CLASS_PK               = "classPK";
public static final String PARAM_TYPE                   = "type";
public static final String PARAM_EXTRA_DATA             = "extraData";
public static final String PARAM_RECEIVED_USER_ID       = "receiverUserId";

@Override @Async(value = "defaultExecutor")
public Future<String> doReceive(Message message) throws Exception {

    String name = Thread.currentThread().getName();
    Map<String, Object> parameters  = message.getValues();
    Long userId                     = (Long)parameters.get(ActivityMessageListener.PARAM_USER_ID);
    Long companyId                  = (Long)parameters.get(ActivityMessageListener.PARAM_COMPANY_ID);
    Date createDate                 = (Date)parameters.get(ActivityMessageListener.PARAM_CREATE_DATE);
    String className                = (String)parameters.get(ActivityMessageListener.PARAM_CLASS_NAME);
    Long classPK                    = (Long)parameters.get(ActivityMessageListener.PARAM_CLASS_PK);
    Integer type                    = (Integer)parameters.get(ActivityMessageListener.PARAM_TYPE);
    String extraData                = (String)parameters.get(ActivityMessageListener.PARAM_EXTRA_DATA);
    Long receiverUserId             = (Long)parameters.get(ActivityMessageListener.PARAM_RECEIVED_USER_ID);
    ActivityLocalServiceUtil.addActivity(userId, companyId, createDate, className, classPK, type, extraData, receiverUserId);

    return new AsyncResult<String>(name);
}
}

Answer 1

编辑：我已提交bug report (SPR-14630)。

我即将向Spring的issue tracker提交错误报告，但是当我准备一个小应用程序来复制错误时，我发现并修复了问题。

首先，在使用ThreadPoolTaskExecutor时，您应该在返回之前调用其initialize()方法：

@Override
public Executor getAsyncExecutor() {
    ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
    executor.setMaxPoolSize(1);
    executor.setCorePoolSize(1);
    executor.setThreadNamePrefix("CUSTOM-");

    // Initialize the executor
    executor.initialize();

    return executor;
}

同样由于某种原因，如果我在同一配置类中定义的@PostConstruct方法中使用bean，它将不会异步运行。原因是@PostConstruct方法在执行getAsyncExecutor()和getAsyncUncaughtExceptionHandler()之前执行：

`AsyncBean.java`

@Component
public class AsyncBean implements IAsyncBean {

    @Override
    @Async
    public void whoAmI() {
        final String message =
                String.format("My name is %s and I am running in %s", getClass().getSimpleName(), Thread.currentThread());

        System.out.println(message);
    }
}

`AsyncDemoApp.java`

@SpringBootApplication
@EnableAsync
public class AsyncDemoApp implements AsyncConfigurer {

    @Autowired
    private IAsyncBean asyncBean;

    public static void main(String[] args) {
        SpringApplication.run(AsyncDemoApp.class, args);
    }

    @Override
    public Executor getAsyncExecutor() {
        System.out.println("AsyncDemoApp.getAsyncExecutor");

        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setThreadNamePrefix("CUSTOM-");
        executor.initialize();

        return executor;
    }

    @Override
    public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
        System.out.println("AsyncDemoApp.getAsyncUncaughtExceptionHandler");
        return (throwable, method, objects)
                -> throwable.printStackTrace();
    }

    @PostConstruct
    public void start() {
        System.out.println("AsyncDemoApp.start");
        asyncBean.whoAmI();
    }
}

输出：

AsyncDemoApp.start
My name is AsyncBean and I am running in Thread[main,5,main]
AsyncDemoApp.getAsyncExecutor
AsyncDemoApp.getAsyncUncaughtExceptionHandler

但是，如果在应用程序上下文可以使用后使用bean，它应该按预期工作：

@SpringBootApplication
@EnableAsync
public class AsyncDemoApp implements AsyncConfigurer {

    public static void main(String[] args) {
        final ConfigurableApplicationContext context = SpringApplication.run(AsyncDemoApp.class, args);

        final IAsyncBean asyncBean = context.getBean(IAsyncBean.class);

        asyncBean.whoAmI();
    }

    @Override
    public Executor getAsyncExecutor() {
        System.out.println("AsyncDemoApp.getAsyncExecutor");

        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setThreadNamePrefix("CUSTOM-");
        executor.initialize();

        return executor;
    }

    @Override
    public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
        System.out.println("AsyncDemoApp.getAsyncUncaughtExceptionHandler");
        return (throwable, method, objects)
                -> throwable.printStackTrace();
    }
}

另一个奇怪的行为是，如果您在同一配置类中 autowire 异步bean，则在配置自定义异步执行程序之前会发生自动连接，因此bean不会异步运行并且在主线程。这可以通过向@PostConstruct添加AsyncBean并使用CommandLineRunner来运行应用来验证（个人认为这是一个错误。至少可以说这种行为非常令人惊讶）：

`AsyncBean`与`@PostConstruct`：

@Component
public class AsyncBean implements IAsyncBean {

    @Override
    @Async
    public void whoAmI() {
        final String message =
                String.format("My name is %s and I am running in %s", getClass().getSimpleName(), Thread.currentThread());

        System.out.println(message);
    }

    @PostConstruct
    public void postConstruct() {
        System.out.println("AsyncBean is constructed");
    }
}

`AsyncDemoApp`实施`CommandLineRunner`：

@SpringBootApplication
@EnableAsync
public class AsyncDemoApp implements AsyncConfigurer, CommandLineRunner {

    @Autowired
    private IAsyncBean asyncBean;

    public static void main(String[] args) {
        SpringApplication.run(AsyncDemoApp.class, args);
    }

    @Override
    public Executor getAsyncExecutor() {
        System.out.println("AsyncDemoApp.getAsyncExecutor");

        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setThreadNamePrefix("CUSTOM-");
        executor.initialize();

        return executor;
    }

    @Override
    public AsyncUncaughtExceptionHandler getAsyncUncaughtExceptionHandler() {
        System.out.println("AsyncDemoApp.getAsyncUncaughtExceptionHandler");
        return (throwable, method, objects)
                -> throwable.printStackTrace();
    }

    @Override
    public void run(String... args) throws Exception {
        System.out.println("AsyncDemoApp.run");
        asyncBean.whoAmI();
    }
}

输出：

AsyncBean is constructed
AsyncDemoApp.getAsyncExecutor
AsyncDemoApp.getAsyncUncaughtExceptionHandler
AsyncDemoApp.run
My name is AsyncBean and I am running in Thread[main,5,main]

还有一件事！ :)如果使用ThreadPoolTaskExecutor，根据您的要求，您可能希望将其守护程序属性设置为true，否则您的应用程序将继续保持运行（对于Web / Worker应用程序而言，这不是一个大问题）。以下是setDaemon(boolean)的JavaDoc所说的内容：

设置此工厂是否应该创建守护程序线程只要应用程序本身正在运行就执行。默认是 “假”：具体工厂通常支持明确取消。因此，如果应用程序关闭，Runnables将默认完成他们的执行。为急切关闭线程指定“true” 仍然在应用程序时主动执行Runnable 本身就会关闭。

实现AsyncConfigurer时，Spring异步不起作用

1 个答案:

`AsyncBean.java`

`AsyncDemoApp.java`

输出：

`AsyncBean`与`@PostConstruct`：

`AsyncDemoApp`实施`CommandLineRunner`：

输出：

实现AsyncConfigurer时，Spring异步不起作用

1 个答案:

AsyncBean.java

AsyncDemoApp.java

输出：

AsyncBean与@PostConstruct：

AsyncDemoApp实施CommandLineRunner：

输出：

`AsyncBean.java`

`AsyncDemoApp.java`

`AsyncBean`与`@PostConstruct`：

`AsyncDemoApp`实施`CommandLineRunner`：