org.springframework.web.context.request.async

Interface CallableProcessingInterceptor

  • All Known Implementing Classes:
    CallableProcessingInterceptorAdapter, TimeoutCallableProcessingInterceptor


    public interface CallableProcessingInterceptor
    Intercepts concurrent request handling, where the concurrent result is obtained by executing a Callable on behalf of the application with an AsyncTaskExecutor.

    A CallableProcessingInterceptor is invoked before and after the invocation of the Callable task in the asynchronous thread, as well as on timeout/error from a container thread, or after completing for any reason including a timeout or network error.

    As a general rule exceptions raised by interceptor methods will cause async processing to resume by dispatching back to the container and using the Exception instance as the concurrent result. Such exceptions will then be processed through the HandlerExceptionResolver mechanism.

    The handleTimeout method can select a value to be used to resume processing.

    Since:
    3.2
    Author:
    Rossen Stoyanchev, Rob Winch
    • Field Summary

      Fields 
      Modifier and Type Field and Description
      static java.lang.Object RESPONSE_HANDLED
      Constant indicating that the response has been handled by this interceptor without a result and that no further interceptors are to be invoked.
      static java.lang.Object RESULT_NONE
      Constant indicating that no result has been determined by this interceptor, giving subsequent interceptors a chance.
    • Method Summary

      All Methods Instance Methods Default Methods 
      Modifier and Type Method and Description
      default <T> void afterCompletion(NativeWebRequest request, java.util.concurrent.Callable<T> task)
      Invoked from a container thread when async processing completes for any reason including timeout or network error.
      default <T> void beforeConcurrentHandling(NativeWebRequest request, java.util.concurrent.Callable<T> task)
      Invoked before the start of concurrent handling in the original thread in which the Callable is submitted for concurrent handling.
      default <T> java.lang.Object handleError(NativeWebRequest request, java.util.concurrent.Callable<T> task, java.lang.Throwable t)
      Invoked from a container thread when an error occurred while processing the async request before the Callable task completes.
      default <T> java.lang.Object handleTimeout(NativeWebRequest request, java.util.concurrent.Callable<T> task)
      Invoked from a container thread when the async request times out before the Callable task completes.
      default <T> void postProcess(NativeWebRequest request, java.util.concurrent.Callable<T> task, java.lang.Object concurrentResult)
      Invoked after the Callable has produced a result in the async thread in which the Callable is executed.
      default <T> void preProcess(NativeWebRequest request, java.util.concurrent.Callable<T> task)
      Invoked after the start of concurrent handling in the async thread in which the Callable is executed and before the actual invocation of the Callable.
    • Method Detail

      • beforeConcurrentHandling

        default <T> void beforeConcurrentHandling(NativeWebRequest request,
                                                  java.util.concurrent.Callable<T> task)
                                           throws java.lang.Exception
        Invoked before the start of concurrent handling in the original thread in which the Callable is submitted for concurrent handling.

        This is useful for capturing the state of the current thread just prior to invoking the Callable. Once the state is captured, it can then be transferred to the new Thread in preProcess(NativeWebRequest, Callable). Capturing the state of Spring Security's SecurityContextHolder and migrating it to the new Thread is a concrete example of where this is useful.

        The default implementation is empty.

        Parameters:
        request - the current request
        task - the task for the current async request
        Throws:
        java.lang.Exception - in case of errors
      • preProcess

        default <T> void preProcess(NativeWebRequest request,
                                    java.util.concurrent.Callable<T> task)
                             throws java.lang.Exception
        Invoked after the start of concurrent handling in the async thread in which the Callable is executed and before the actual invocation of the Callable.

        The default implementation is empty.

        Parameters:
        request - the current request
        task - the task for the current async request
        Throws:
        java.lang.Exception - in case of errors
      • postProcess

        default <T> void postProcess(NativeWebRequest request,
                                     java.util.concurrent.Callable<T> task,
                                     java.lang.Object concurrentResult)
                              throws java.lang.Exception
        Invoked after the Callable has produced a result in the async thread in which the Callable is executed. This method may be invoked later than afterTimeout or afterCompletion depending on when the Callable finishes processing.

        The default implementation is empty.

        Parameters:
        request - the current request
        task - the task for the current async request
        concurrentResult - the result of concurrent processing, which could be a Throwable if the Callable raised an exception
        Throws:
        java.lang.Exception - in case of errors
      • handleTimeout

        default <T> java.lang.Object handleTimeout(NativeWebRequest request,
                                                   java.util.concurrent.Callable<T> task)
                                            throws java.lang.Exception
        Invoked from a container thread when the async request times out before the Callable task completes. Implementations may return a value, including an Exception, to use instead of the value the Callable did not return in time.

        The default implementation always returns RESULT_NONE.

        Parameters:
        request - the current request
        task - the task for the current async request
        Returns:
        a concurrent result value; if the value is anything other than RESULT_NONE or RESPONSE_HANDLED, concurrent processing is resumed and subsequent interceptors are not invoked
        Throws:
        java.lang.Exception - in case of errors
      • handleError

        default <T> java.lang.Object handleError(NativeWebRequest request,
                                                 java.util.concurrent.Callable<T> task,
                                                 java.lang.Throwable t)
                                          throws java.lang.Exception
        Invoked from a container thread when an error occurred while processing the async request before the Callable task completes. Implementations may return a value, including an Exception, to use instead of the value the Callable did not return in time.

        The default implementation always returns RESULT_NONE.

        Parameters:
        request - the current request
        task - the task for the current async request
        t - the error that occurred while request processing
        Returns:
        a concurrent result value; if the value is anything other than RESULT_NONE or RESPONSE_HANDLED, concurrent processing is resumed and subsequent interceptors are not invoked
        Throws:
        java.lang.Exception - in case of errors
        Since:
        5.0
      • afterCompletion

        default <T> void afterCompletion(NativeWebRequest request,
                                         java.util.concurrent.Callable<T> task)
                                  throws java.lang.Exception
        Invoked from a container thread when async processing completes for any reason including timeout or network error.

        The default implementation is empty.

        Parameters:
        request - the current request
        task - the task for the current async request
        Throws:
        java.lang.Exception - in case of errors