@Beta @GwtIncompatible public abstract class AbstractIdleService extends Object implements Service
startUp()
and shutDown()
methods, each which
run in a executor which by default uses a separate thread for each method.Service.Listener, Service.State
Modifier | Constructor and Description |
---|---|
protected |
AbstractIdleService()
Constructor for use by subclasses.
|
Modifier and Type | Method and Description |
---|---|
void |
addListener(Service.Listener listener,
Executor executor)
Registers a
Service.Listener to be executed on the given
executor. |
void |
awaitRunning()
Waits for the
Service to reach the running state. |
void |
awaitRunning(long timeout,
TimeUnit unit)
Waits for the
Service to reach the running state for no more
than the given time. |
void |
awaitTerminated()
Waits for the
Service to reach the terminated state. |
void |
awaitTerminated(long timeout,
TimeUnit unit)
Waits for the
Service to reach a terminal state (either terminated or failed ) for no more than the given time. |
protected Executor |
executor()
Returns the
Executor that will be used to run this service. |
Throwable |
failureCause()
Returns the
Throwable that caused this service to fail. |
boolean |
isRunning()
Returns
true if this service is running. |
protected String |
serviceName()
Returns the name of this service.
|
protected abstract void |
shutDown()
Stop the service.
|
Service |
startAsync()
If the service state is
Service.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()
|
String |
toString()
Returns a string representation of the object.
|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
awaitRunning, awaitTerminated
protected AbstractIdleService()
protected Executor executor()
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.public String toString()
java.lang.Object
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())
public final boolean isRunning()
Service
true
if this service is running.public final Service.State state()
Service
public final void addListener(Service.Listener listener, Executor executor)
Service
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.
addListener
in interface Service
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, consider MoreExecutors.directExecutor()
.public final Throwable failureCause()
Service
Throwable
that caused this service to fail.failureCause
in interface Service
@CanIgnoreReturnValue public final Service startAsync()
Service
Service.State.NEW
, this initiates service startup and returns
immediately. A stopped service may not be restarted.startAsync
in interface Service
@CanIgnoreReturnValue public final Service stopAsync()
Service
public final void awaitRunning()
Service
Service
to reach the running state.awaitRunning
in interface Service
public final void awaitRunning(long timeout, TimeUnit unit) throws TimeoutException
Service
Service
to reach the running state for no more
than the given time.awaitRunning
in interface Service
timeout
- the maximum time to waitunit
- the time unit of the timeout argumentTimeoutException
- if the service has not reached the given state within the deadlinepublic final void awaitTerminated()
Service
Service
to reach the terminated state.awaitTerminated
in interface Service
public final void awaitTerminated(long timeout, TimeUnit unit) throws TimeoutException
Service
Service
to reach a terminal state (either terminated
or failed
) for no more than the given time.awaitTerminated
in interface Service
timeout
- the maximum time to waitunit
- the time unit of the timeout argumentTimeoutException
- if the service has not reached the given state within the deadlineprotected String serviceName()
AbstractIdleService
may include the name in debugging
output.Copyright © 2010–2019. All rights reserved.