com.bluegosling.concurrent.executors

Interface InterceptingExecutorService.Decorator

Enclosing class:

InterceptingExecutorService

public static interface InterceptingExecutorService.Decorator

A decorator, that can perform actions before and after each task.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	InterceptingExecutorService.Decorator.Builder Builds a decorator, composing up to three functional interfaces.

Method Summary

Modifier and Type	Method and Description
default void	afterFailed(ExecutorService delegate, Callable<?> task, Throwable cause) Performs actions after the given task has failed.
default <T> void	afterFinish(ExecutorService delegate, Callable<T> task, T result) Performs actions after the given task has completed successfully.
static InterceptingExecutorService.Interceptor	asInterceptor(List<? extends InterceptingExecutorService.Decorator> decorators) Converts a list of decorators into a single interceptor.
default void	beforeStart(ExecutorService delegate, Callable<?> task) Performs actions before the given task.
static InterceptingExecutorService.Decorator.Builder	builder() Returns a new builder, for creating a decorator from simple lambda expressions.

Method Detail

beforeStart

default void beforeStart(ExecutorService delegate,
                         Callable<?> task)

Performs actions before the given task. Implementations should not call task.call().

Parameters:

delegate - the underlying executor that is executing the task

task - the task that is running

afterFinish

default <T> void afterFinish(ExecutorService delegate,
                             Callable<T> task,
                             T result)

Performs actions after the given task has completed successfully.

Parameters:

delegate - the underlying executor that is executing the task

task - the task that ran

result - the result produced by the task

afterFailed

default void afterFailed(ExecutorService delegate,
                         Callable<?> task,
                         Throwable cause)

Performs actions after the given task has failed.

Parameters:

delegate - the underlying executor that is executing the task

task - the task that failed

cause - the cause of failure

builder

static InterceptingExecutorService.Decorator.Builder builder()

Returns a new builder, for creating a decorator from simple lambda expressions.

Returns:

a new builder

asInterceptor

static InterceptingExecutorService.Interceptor asInterceptor(List<? extends InterceptingExecutorService.Decorator> decorators)

Converts a list of decorators into a single interceptor. The interceptor invokes each decorator before the task, in the order they appear in the list. After the task, the decorators are invoked in the opposite order.

Execution of the task is short-circuited if a decorator throws an exception from its beforeStart(java.util.concurrent.ExecutorService, java.util.concurrent.Callable<?>) action. In such an event, subsequent decorators are skipped. For every invocation of beforeStart(java.util.concurrent.ExecutorService, java.util.concurrent.Callable<?>), either afterFinish(java.util.concurrent.ExecutorService, java.util.concurrent.Callable<T>, T) or afterFailed(java.util.concurrent.ExecutorService, java.util.concurrent.Callable<?>, java.lang.Throwable) will be invoked. So, if a decorator throws an exception, short-circuiting task execution, any decorators already invoked will have their afterFailed(java.util.concurrent.ExecutorService, java.util.concurrent.Callable<?>, java.lang.Throwable) action invoked.

Parameters:

decorators - a list of decorators

Returns:

an interceptor that invokes the given decorators