Package com.google.common.util.concurrent

Class AbstractIdleService

  • All Implemented Interfaces:
    Service
    @GwtIncompatible
public abstract class AbstractIdleService
extends Object
implements Service
    Base class for services that do not need a thread while "running" but may need one during startup and shutdown. Subclasses can implement startUp() and shutDown() methods, each which run in a executor which by default uses a separate thread for each method.
    Since:
    1.0
    Author:
    Chris Nokleberg

    • Constructor Detail

    • Method Detail

      • executor

        protected Executor executor()
        Returns the Executor that will be used to run this service. Subclasses may override this method to use a custom Executor, which may configure its worker thread with a specific name, thread group or priority. The returned executor's execute() method is called when this service is started and stopped, and should return promptly.

      • toString

        public String toString()
        Description copied from class: java.lang.Object
        Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

        The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of: 

         getClass().getName() + '@' + Integer.toHexString(hashCode())
        Overrides:
        toString in class Object
        Returns:
        a string representation of the object.

      • addListener

        public final void addListener​(Service.Listener listener,
                              Executor executor)
        Description copied from interface: Service
        Registers a Service.Listener to be executed on the given executor. The listener will have the corresponding transition method called whenever the service changes state. The listener will not have previous state changes replayed, so it is suggested that listeners are added before the service starts.

        addListener guarantees execution ordering across calls to a given listener but not across calls to multiple listeners. Specifically, a given listener will have its callbacks invoked in the same order as the underlying service enters those states. Additionally, at most one of the listener's callbacks will execute at once. However, multiple listeners' callbacks may execute concurrently, and listeners may execute in an order different from the one in which they were registered.

        RuntimeExceptions thrown by a listener will be caught and logged. Any exception thrown during Executor.execute (e.g., a RejectedExecutionException) will be caught and logged.

        Specified by:
        addListener in interface Service
        Parameters:
        listener - the listener to run when the service changes state is complete
        executor - the executor in which the listeners callback methods will be run. For fast, lightweight listeners that would be safe to execute in any thread, consider MoreExecutors.directExecutor().
        Since:
        13.0

      • stopAsync

        @CanIgnoreReturnValue
public final Service stopAsync()
        Description copied from interface: Service
        If the service is starting or running, this initiates service shutdown and returns immediately. If the service is new, it is terminated without having been started nor stopped. If the service has already been stopped, this method returns immediately without taking action.
        Specified by:
        stopAsync in interface Service
        Returns:
        this
        Since:
        15.0