AbstractIdleService (Guava: Google Core Libraries for Java 23.5-jre API)

java.lang.Object
- com.google.common.util.concurrent.AbstractIdleService

All Implemented Interfaces:

Service
```
@Beta
 @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

Nested Class Summary
- Nested classes/interfaces inherited from interface com.google.common.util.concurrent.Service
  Service.Listener, Service.State

Constructor Summary

Constructors
Modifier Constructor and Description

protected AbstractIdleService()
Constructor for use by subclasses.

Constructors
Modifier	Constructor and Description
`protected`	`AbstractIdleService()` Constructor for use by subclasses.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
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()` If the service is starting or running, this initiates service shutdown and returns immediately.
`String`	`toString()` Returns a string representation of the object.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - AbstractIdleService
```
protected AbstractIdleService()
```
    Constructor for use by subclasses.
- Method Detail
  - startUp
```
protected abstract void startUp()
                         throws Exception
```
    Start the service.
    
    Throws:
    
    Exception
  - shutDown
```
protected abstract void shutDown()
                          throws Exception
```
    Stop the service.
    
    Throws:
    
    Exception
  - 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.
  - isRunning
```
public final boolean isRunning()
```
    Description copied from interface: Service
    
    Returns true if this service is running.
    
    Specified by:
    
    isRunning in interface Service
  - state
```
public final Service.State state()
```
    Description copied from interface: Service
    
    Returns the lifecycle state of the service.
    
    Specified by:
    
    state in interface Service
  - 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
  - failureCause
```
public final Throwable failureCause()
```
    Description copied from interface: Service
    
    Returns the Throwable that caused this service to fail.
    
    Specified by:
    
    failureCause in interface Service
    
    Since:
    
    14.0
  - startAsync
```
public final Service startAsync()
```
    Description copied from interface: Service
    
    If the service state is Service.State.NEW, this initiates service startup and returns immediately. A stopped service may not be restarted.
    
    Specified by:
    
    startAsync in interface Service
    
    Returns:
    
    this
    
    Since:
    
    15.0
  - stopAsync
```
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
  - awaitRunning
```
public final void awaitRunning()
```
    Description copied from interface: Service
    
    Waits for the Service to reach the running state.
    
    Specified by:
    
    awaitRunning in interface Service
    
    Since:
    
    15.0
  - awaitRunning
```
public final void awaitRunning(long timeout,
                               TimeUnit unit)
                        throws TimeoutException
```
    Description copied from interface: Service
    
    Waits for the Service to reach the running state for no more than the given time.
    
    Specified by:
    
    awaitRunning in interface Service
    
    Parameters:
    
    timeout - the maximum time to wait
    
    unit - the time unit of the timeout argument
    
    Throws:
    
    TimeoutException - if the service has not reached the given state within the deadline
    
    Since:
    
    15.0
  - awaitTerminated
```
public final void awaitTerminated()
```
    Description copied from interface: Service
    
    Waits for the Service to reach the terminated state.
    
    Specified by:
    
    awaitTerminated in interface Service
    
    Since:
    
    15.0
  - awaitTerminated
```
public final void awaitTerminated(long timeout,
                                  TimeUnit unit)
                           throws TimeoutException
```
    Description copied from interface: Service
    
    Waits for the Service to reach a terminal state (either terminated or failed) for no more than the given time.
    
    Specified by:
    
    awaitTerminated in interface Service
    
    Parameters:
    
    timeout - the maximum time to wait
    
    unit - the time unit of the timeout argument
    
    Throws:
    
    TimeoutException - if the service has not reached the given state within the deadline
    
    Since:
    
    15.0
  - serviceName
```
protected String serviceName()
```
    Returns the name of this service. AbstractIdleService may include the name in debugging output.
    
    Since:
    
    14.0

Class AbstractIdleService

Nested Class Summary

Nested classes/interfaces inherited from interface com.google.common.util.concurrent.Service

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

AbstractIdleService

Method Detail

startUp

shutDown

executor

toString

isRunning

state

addListener

failureCause

startAsync

stopAsync

awaitRunning

awaitRunning

awaitTerminated

awaitTerminated

serviceName