Class AbstractIdleService
- java.lang.Object
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- com.google.common.util.concurrent.AbstractIdleService
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- All Implemented Interfaces:
Service
@GwtIncompatible public abstract class AbstractIdleService extends java.lang.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 implementstartUp()
andshutDown()
methods, each which run in an executor which by default uses a separate thread for each method.- Since:
- 1.0
- Author:
- Chris Nokleberg
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Nested Class Summary
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Nested classes/interfaces inherited from interface com.google.common.util.concurrent.Service
Service.Listener, Service.State
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Constructor Summary
Constructors Modifier Constructor Description protected
AbstractIdleService()
Constructor for use by subclasses.
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description void
addListener(Service.Listener listener, java.util.concurrent.Executor executor)
Registers aService.Listener
to be executed on the given executor.void
awaitRunning()
Waits for theService
to reach the running state.void
awaitRunning(long timeout, java.util.concurrent.TimeUnit unit)
Waits for theService
to reach the running state for no more than the given time.void
awaitTerminated()
Waits for theService
to reach the terminated state.void
awaitTerminated(long timeout, java.util.concurrent.TimeUnit unit)
Waits for theService
to reach a terminal state (eitherterminated
orfailed
) for no more than the given time.protected java.util.concurrent.Executor
executor()
Returns theExecutor
that will be used to run this service.java.lang.Throwable
failureCause()
Returns theThrowable
that caused this service to fail.boolean
isRunning()
Returnstrue
if this service is running.protected java.lang.String
serviceName()
Returns the name of this service.protected abstract void
shutDown()
Stop the service.Service
startAsync()
If the service state isService.State.NEW
, this initiates service startup and returns immediately.protected abstract void
startUp()
Start the service.Service.State
state()
Returns the lifecycle state of the service.Service
stopAsync()
java.lang.String
toString()
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Constructor Detail
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AbstractIdleService
protected AbstractIdleService()
Constructor for use by subclasses.
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Method Detail
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startUp
protected abstract void startUp() throws java.lang.Exception
Start the service.- Throws:
java.lang.Exception
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shutDown
protected abstract void shutDown() throws java.lang.Exception
Stop the service.- Throws:
java.lang.Exception
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executor
protected java.util.concurrent.Executor executor()
Returns theExecutor
that will be used to run this service. Subclasses may override this method to use a customExecutor
, which may configure its worker thread with a specific name, thread group or priority. The returned executor'sexecute()
method is called when this service is started and stopped, and should return promptly.
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toString
public java.lang.String toString()
- Overrides:
toString
in classjava.lang.Object
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isRunning
public final boolean isRunning()
Description copied from interface:Service
Returnstrue
if this service is running.
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state
public final Service.State state()
Description copied from interface:Service
Returns the lifecycle state of the service.
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addListener
public final void addListener(Service.Listener listener, java.util.concurrent.Executor executor)
Description copied from interface:Service
Registers aService.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., aRejectedExecutionException
) will be caught and logged.- Specified by:
addListener
in interfaceService
- Parameters:
listener
- the listener to run when the service changes state is completeexecutor
- the executor in which the listeners callback methods will be run. For fast, lightweight listeners that would be safe to execute in any thread, considerMoreExecutors.directExecutor()
.- Since:
- 13.0
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failureCause
public final java.lang.Throwable failureCause()
Description copied from interface:Service
Returns theThrowable
that caused this service to fail.- Specified by:
failureCause
in interfaceService
- Since:
- 14.0
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startAsync
@CanIgnoreReturnValue public final Service startAsync()
Description copied from interface:Service
If the service state isService.State.NEW
, this initiates service startup and returns immediately. A stopped service may not be restarted.- Specified by:
startAsync
in interfaceService
- Returns:
- this
- Since:
- 15.0
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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.
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awaitRunning
public final void awaitRunning()
Description copied from interface:Service
Waits for theService
to reach the running state.- Specified by:
awaitRunning
in interfaceService
- Since:
- 15.0
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awaitRunning
public final void awaitRunning(long timeout, java.util.concurrent.TimeUnit unit) throws java.util.concurrent.TimeoutException
Description copied from interface:Service
Waits for theService
to reach the running state for no more than the given time.- Specified by:
awaitRunning
in interfaceService
- Parameters:
timeout
- the maximum time to waitunit
- the time unit of the timeout argument- Throws:
java.util.concurrent.TimeoutException
- if the service has not reached the given state within the deadline- Since:
- 15.0
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awaitTerminated
public final void awaitTerminated()
Description copied from interface:Service
Waits for theService
to reach the terminated state.- Specified by:
awaitTerminated
in interfaceService
- Since:
- 15.0
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awaitTerminated
public final void awaitTerminated(long timeout, java.util.concurrent.TimeUnit unit) throws java.util.concurrent.TimeoutException
Description copied from interface:Service
Waits for theService
to reach a terminal state (eitherterminated
orfailed
) for no more than the given time.- Specified by:
awaitTerminated
in interfaceService
- Parameters:
timeout
- the maximum time to waitunit
- the time unit of the timeout argument- Throws:
java.util.concurrent.TimeoutException
- if the service has not reached the given state within the deadline- Since:
- 15.0
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serviceName
protected java.lang.String serviceName()
Returns the name of this service.AbstractIdleService
may include the name in debugging output.- Since:
- 14.0
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