javafx.concurrent

Class Service<V>

java.lang.Object

javafx.concurrent.Service<V>

Type Parameters:

V -

All Implemented Interfaces:

Worker<V>, EventTarget

Direct Known Subclasses:

ScheduledService

public abstract class Service<V>
extends Object
implements Worker<V>, EventTarget

A Service is a non-visual component encapsulating the information required to perform some work on one or more background threads. As part of the JavaFX UI library, the Service knows about the JavaFX Application thread and is designed to relieve the application developer from the burden of managing multithreaded code that interacts with the user interface. As such, all of the methods and state on the Service are intended to be invoked exclusively from the JavaFX Application thread. The only exception to this, is when initially configuring a Service, which may safely be done from any thread, and initially starting a Service, which may also safely be done from any thread. However, once the Service has been initialized and started, it may only thereafter be used from the FX thread.

A Service creates and manages a Task that performs the work on the background thread. Service implements Worker. As such, you can observe the state of the background task and optionally cancel it. Service is a reusable Worker, meaning that it can be reset and restarted. Due to this, a Service can be constructed declaratively and restarted on demand. Once a Service is started, it will schedule its Task and listen for changes to the state of the Task. A Task does not hold a reference to the Service that started it, meaning that a running Task will not prevent the Service from being garbage collected.

If an Executor is specified on the Service, then it will be used to actually execute the service. Otherwise, a daemon thread will be created and executed. If you wish to create non-daemon threads, then specify a custom Executor (for example, you could use a ThreadPoolExecutor with a custom ThreadFactory).

Because a Service is intended to simplify declarative use cases, subclasses should expose as properties the input parameters to the work to be done. For example, suppose I wanted to write a Service which read the first line from any URL and returned it as a String. Such a Service might be defined, such that it had a single property, url. It might be implemented as:

public static class FirstLineService extends Service<String> {
         private StringProperty url = new SimpleStringProperty(this, "url");
         public final void setUrl(String value) { url.set(value); }
         public final String getUrl() { return url.get(); }
         public final StringProperty urlProperty() { return url; }

         protected Task createTask() {
             final String _url = getUrl();
             return new Task&ltString>() {
                 protected String call() throws Exception {
                     URL u = new URL(_url);
                     BufferedReader in = new BufferedReader(
                             new InputStreamReader(u.openStream()));
                     String result = in.readLine();
                     in.close();
                     return result;
                 }
             };
         }
     }

The Service by default uses a thread pool Executor with some unspecified default or maximum thread pool size. This is done so that naive code will not completely swamp the system by creating thousands of Threads.

Since:

JavaFX 2.0

Property Summary

All MethodsInstance MethodsConcrete Methods
Type	Property and Description
`ReadOnlyObjectProperty<Throwable>`	`exception` Gets the ReadOnlyObjectProperty representing any exception which occurred.
`ObjectProperty<Executor>`	`executor` The executor to use for running this Service.
`ReadOnlyStringProperty`	`message` Gets the ReadOnlyStringProperty representing the message.
`ObjectProperty<EventHandler<WorkerStateEvent>>`	`onCancelled` The onCancelled event handler is called whenever the Task state transitions to the CANCELLED state.
`ObjectProperty<EventHandler<WorkerStateEvent>>`	`onFailed` The onFailed event handler is called whenever the Task state transitions to the FAILED state.
`ObjectProperty<EventHandler<WorkerStateEvent>>`	`onReady` The onReady event handler is called whenever the Task state transitions to the READY state.
`ObjectProperty<EventHandler<WorkerStateEvent>>`	`onRunning` The onRunning event handler is called whenever the Task state transitions to the RUNNING state.
`ObjectProperty<EventHandler<WorkerStateEvent>>`	`onScheduled` The onSchedule event handler is called whenever the Task state transitions to the SCHEDULED state.
`ObjectProperty<EventHandler<WorkerStateEvent>>`	`onSucceeded` The onSucceeded event handler is called whenever the Task state transitions to the SUCCEEDED state.
`ReadOnlyDoubleProperty`	`progress` Gets the ReadOnlyDoubleProperty representing the progress.
`ReadOnlyBooleanProperty`	`running` Gets the ReadOnlyBooleanProperty representing whether the Worker is running.
`ReadOnlyObjectProperty<Worker.State>`	`state` Gets the ReadOnlyObjectProperty representing the current state.
`ReadOnlyStringProperty`	`title` Gets the ReadOnlyStringProperty representing the title.
`ReadOnlyDoubleProperty`	`totalWork` Gets the ReadOnlyDoubleProperty representing the maximum amount of work that needs to be done.
`ReadOnlyObjectProperty<V>`	`value` Gets the ReadOnlyObjectProperty representing the value.
`ReadOnlyDoubleProperty`	`workDone` Gets the ReadOnlyDoubleProperty representing the current progress.

Nested Class Summary
- Nested classes/interfaces inherited from interface javafx.concurrent.Worker
  Worker.State

Constructor Summary

Constructors
Modifier Constructor and Description

protected Service()
Create a new Service.

Constructors
Modifier	Constructor and Description
`protected`	`Service()` Create a new Service.

Method Summary

All MethodsInstance MethodsAbstract MethodsConcrete Methods
Modifier and Type	Method and Description
`<T extends Event> void`	`addEventFilter(EventType<T> eventType, EventHandler<? super T> eventFilter)` Registers an event filter to this task.
`<T extends Event> void`	`addEventHandler(EventType<T> eventType, EventHandler<? super T> eventHandler)` Registers an event handler to this task.
`EventDispatchChain`	`buildEventDispatchChain(EventDispatchChain tail)` Construct an event dispatch chain for this target.
`boolean`	`cancel()` Cancels any currently running Task, if any.
`protected void`	`cancelled()` A protected convenience method for subclasses, called whenever the state of the Service has transitioned to the CANCELLED state.
`protected abstract Task<V>`	`createTask()` Invoked after the Service is started on the JavaFX Application Thread.
`ReadOnlyObjectProperty<Throwable>`	`exceptionProperty()` Gets the ReadOnlyObjectProperty representing any exception which occurred.
`protected void`	`executeTask(Task<V> task)` Uses the `executor` defined on this Service to execute the given task.
`ObjectProperty<Executor>`	`executorProperty()` The executor to use for running this Service.
`protected void`	`failed()` A protected convenience method for subclasses, called whenever the state of the Service has transitioned to the FAILED state.
`protected void`	`fireEvent(Event event)` Fires the specified event.
`Throwable`	`getException()` Gets the value of the property exception.
`Executor`	`getExecutor()` Gets the value of the property executor.
`String`	`getMessage()` Gets the value of the property message.
`EventHandler<WorkerStateEvent>`	`getOnCancelled()` The onCancelled event handler is called whenever the Task state transitions to the CANCELLED state.
`EventHandler<WorkerStateEvent>`	`getOnFailed()` The onFailed event handler is called whenever the Task state transitions to the FAILED state.
`EventHandler<WorkerStateEvent>`	`getOnReady()` The onReady event handler is called whenever the Task state transitions to the READY state.
`EventHandler<WorkerStateEvent>`	`getOnRunning()` The onRunning event handler is called whenever the Task state transitions to the RUNNING state.
`EventHandler<WorkerStateEvent>`	`getOnScheduled()` The onSchedule event handler is called whenever the Task state transitions to the SCHEDULED state.
`EventHandler<WorkerStateEvent>`	`getOnSucceeded()` The onSucceeded event handler is called whenever the Task state transitions to the SUCCEEDED state.
`double`	`getProgress()` Gets the value of the property progress.
`Worker.State`	`getState()` Gets the value of the property state.
`String`	`getTitle()` Gets the value of the property title.
`double`	`getTotalWork()` Gets the value of the property totalWork.
`V`	`getValue()` Gets the value of the property value.
`double`	`getWorkDone()` Gets the value of the property workDone.
`boolean`	`isRunning()` Gets the value of the property running.
`ReadOnlyStringProperty`	`messageProperty()` Gets the ReadOnlyStringProperty representing the message.
`ObjectProperty<EventHandler<WorkerStateEvent>>`	`onCancelledProperty()` The onCancelled event handler is called whenever the Task state transitions to the CANCELLED state.
`ObjectProperty<EventHandler<WorkerStateEvent>>`	`onFailedProperty()` The onFailed event handler is called whenever the Task state transitions to the FAILED state.
`ObjectProperty<EventHandler<WorkerStateEvent>>`	`onReadyProperty()` The onReady event handler is called whenever the Task state transitions to the READY state.
`ObjectProperty<EventHandler<WorkerStateEvent>>`	`onRunningProperty()` The onRunning event handler is called whenever the Task state transitions to the RUNNING state.
`ObjectProperty<EventHandler<WorkerStateEvent>>`	`onScheduledProperty()` The onSchedule event handler is called whenever the Task state transitions to the SCHEDULED state.
`ObjectProperty<EventHandler<WorkerStateEvent>>`	`onSucceededProperty()` The onSucceeded event handler is called whenever the Task state transitions to the SUCCEEDED state.
`ReadOnlyDoubleProperty`	`progressProperty()` Gets the ReadOnlyDoubleProperty representing the progress.
`protected void`	`ready()` A protected convenience method for subclasses, called whenever the state of the Service has transitioned to the READY state.
`<T extends Event> void`	`removeEventFilter(EventType<T> eventType, EventHandler<? super T> eventFilter)` Unregisters a previously registered event filter from this task.
`<T extends Event> void`	`removeEventHandler(EventType<T> eventType, EventHandler<? super T> eventHandler)` Unregisters a previously registered event handler from this task.
`void`	`reset()` Resets the Service.
`void`	`restart()` Cancels any currently running Task, if any, and restarts this Service.
`protected void`	`running()` A protected convenience method for subclasses, called whenever the state of the Service has transitioned to the RUNNING state.
`ReadOnlyBooleanProperty`	`runningProperty()` Gets the ReadOnlyBooleanProperty representing whether the Worker is running.
`protected void`	`scheduled()` A protected convenience method for subclasses, called whenever the state of the Service has transitioned to the SCHEDULED state.
`protected <T extends Event> void`	`setEventHandler(EventType<T> eventType, EventHandler<? super T> eventHandler)` Sets the handler to use for this event type.
`void`	`setExecutor(Executor value)` Sets the value of the property executor.
`void`	`setOnCancelled(EventHandler<WorkerStateEvent> value)` The onCancelled event handler is called whenever the Task state transitions to the CANCELLED state.
`void`	`setOnFailed(EventHandler<WorkerStateEvent> value)` The onFailed event handler is called whenever the Task state transitions to the FAILED state.
`void`	`setOnReady(EventHandler<WorkerStateEvent> value)` The onReady event handler is called whenever the Task state transitions to the READY state.
`void`	`setOnRunning(EventHandler<WorkerStateEvent> value)` The onRunning event handler is called whenever the Task state transitions to the RUNNING state.
`void`	`setOnScheduled(EventHandler<WorkerStateEvent> value)` The onSchedule event handler is called whenever the Task state transitions to the SCHEDULED state.
`void`	`setOnSucceeded(EventHandler<WorkerStateEvent> value)` The onSucceeded event handler is called whenever the Task state transitions to the SUCCEEDED state.
`void`	`start()` Starts this Service.
`ReadOnlyObjectProperty<Worker.State>`	`stateProperty()` Gets the ReadOnlyObjectProperty representing the current state.
`protected void`	`succeeded()` A protected convenience method for subclasses, called whenever the state of the Service has transitioned to the SUCCEEDED state.
`ReadOnlyStringProperty`	`titleProperty()` Gets the ReadOnlyStringProperty representing the title.
`ReadOnlyDoubleProperty`	`totalWorkProperty()` Gets the ReadOnlyDoubleProperty representing the maximum amount of work that needs to be done.
`ReadOnlyObjectProperty<V>`	`valueProperty()` Gets the ReadOnlyObjectProperty representing the value.
`ReadOnlyDoubleProperty`	`workDoneProperty()` Gets the ReadOnlyDoubleProperty representing the current progress.

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

Property Detail
- state
```
public final ReadOnlyObjectProperty<Worker.State> stateProperty
```
  Specified by:
  
  stateProperty in interface Worker<V>
  
  Returns:
  
  The property representing the state
  
  See Also:
  
  getState()
- value
```
public final ReadOnlyObjectProperty<V> valueProperty
```
  Specified by:
  
  valueProperty in interface Worker<V>
  
  Returns:
  
  The property representing the current value
  
  See Also:
  
  getValue()
- exception
```
public final ReadOnlyObjectProperty<Throwable> exceptionProperty
```
  Specified by:
  
  exceptionProperty in interface Worker<V>
  
  Returns:
  
  the property representing the exception
  
  See Also:
  
  getException()
- workDone
```
public final ReadOnlyDoubleProperty workDoneProperty
```
  Specified by:
  
  workDoneProperty in interface Worker<V>
  
  Returns:
  
  The property representing the amount of work done
  
  See Also:
  
  getWorkDone()
- totalWork
```
public final ReadOnlyDoubleProperty totalWorkProperty
```
  Specified by:
  
  totalWorkProperty in interface Worker<V>
  
  Returns:
  
  the property representing the total work to be done
  
  See Also:
  
  getTotalWork()
- progress
```
public final ReadOnlyDoubleProperty progressProperty
```
  Specified by:
  
  progressProperty in interface Worker<V>
  
  Returns:
  
  the property representing the progress
  
  See Also:
  
  getProgress()
- running
```
public final ReadOnlyBooleanProperty runningProperty
```
  Specified by:
  
  runningProperty in interface Worker<V>
  
  Returns:
  
  the property representing whether the worker is running
  
  See Also:
  
  isRunning()
- message
```
public final ReadOnlyStringProperty messageProperty
```
  Specified by:
  
  messageProperty in interface Worker<V>
  
  Returns:
  
  a property representing the current message
  
  See Also:
  
  getMessage()
- title
```
public final ReadOnlyStringProperty titleProperty
```
  Specified by:
  
  titleProperty in interface Worker<V>
  
  Returns:
  
  the property representing the current title
  
  See Also:
  
  getTitle()
- executor
```
public final ObjectProperty<Executor> executorProperty
```
  The executor to use for running this Service. If no executor is specified, then a new daemon thread will be created and used for running the Service using some default executor.
  
  See Also:
  
  getExecutor(), setExecutor(Executor)
- onReady
```
public final ObjectProperty<EventHandler<WorkerStateEvent>> onReadyProperty
```
  The onReady event handler is called whenever the Task state transitions to the READY state.
  
  Since:
  
  JavaFX 2.1
  
  See Also:
  
  getOnReady(), setOnReady(EventHandler)
- onScheduled
```
public final ObjectProperty<EventHandler<WorkerStateEvent>> onScheduledProperty
```
  The onSchedule event handler is called whenever the Task state transitions to the SCHEDULED state.
  
  Since:
  
  JavaFX 2.1
  
  See Also:
  
  getOnScheduled(), setOnScheduled(EventHandler)
- onRunning
```
public final ObjectProperty<EventHandler<WorkerStateEvent>> onRunningProperty
```
  The onRunning event handler is called whenever the Task state transitions to the RUNNING state.
  
  Since:
  
  JavaFX 2.1
  
  See Also:
  
  getOnRunning(), setOnRunning(EventHandler)
- onSucceeded
```
public final ObjectProperty<EventHandler<WorkerStateEvent>> onSucceededProperty
```
  The onSucceeded event handler is called whenever the Task state transitions to the SUCCEEDED state.
  
  Since:
  
  JavaFX 2.1
  
  See Also:
  
  getOnSucceeded(), setOnSucceeded(EventHandler)
- onCancelled
```
public final ObjectProperty<EventHandler<WorkerStateEvent>> onCancelledProperty
```
  The onCancelled event handler is called whenever the Task state transitions to the CANCELLED state.
  
  Since:
  
  JavaFX 2.1
  
  See Also:
  
  getOnCancelled(), setOnCancelled(EventHandler)
- onFailed
```
public final ObjectProperty<EventHandler<WorkerStateEvent>> onFailedProperty
```
  The onFailed event handler is called whenever the Task state transitions to the FAILED state.
  
  Since:
  
  JavaFX 2.1
  
  See Also:
  
  getOnFailed(), setOnFailed(EventHandler)

Constructor Detail
- Service
```
protected Service()
```
  Create a new Service.

Method Detail
- getState
```
public final Worker.State getState()
```
  Gets the value of the property state.
  
  Specified by:
  
  getState in interface Worker<V>
  
  Returns:
  
  The current state of this Worker
- stateProperty
```
public final ReadOnlyObjectProperty<Worker.State> stateProperty()
```
  Description copied from interface: Worker
  
  Gets the ReadOnlyObjectProperty representing the current state.
  
  Specified by:
  
  stateProperty in interface Worker<V>
  
  Returns:
  
  The property representing the state
  
  See Also:
  
  getState()
- getValue
```
public final V getValue()
```
  Gets the value of the property value.
  
  Specified by:
  
  getValue in interface Worker<V>
  
  Returns:
  
  the current value of this Worker
- valueProperty
```
public final ReadOnlyObjectProperty<V> valueProperty()
```
  Description copied from interface: Worker
  
  Gets the ReadOnlyObjectProperty representing the value.
  
  Specified by:
  
  valueProperty in interface Worker<V>
  
  Returns:
  
  The property representing the current value
  
  See Also:
  
  getValue()
- getException
```
public final Throwable getException()
```
  Gets the value of the property exception.
  
  Specified by:
  
  getException in interface Worker<V>
  
  Returns:
  
  the exception, if one occurred
- exceptionProperty
```
public final ReadOnlyObjectProperty<Throwable> exceptionProperty()
```
  Description copied from interface: Worker
  
  Gets the ReadOnlyObjectProperty representing any exception which occurred.
  
  Specified by:
  
  exceptionProperty in interface Worker<V>
  
  Returns:
  
  the property representing the exception
  
  See Also:
  
  getException()
- getWorkDone
```
public final double getWorkDone()
```
  Gets the value of the property workDone.
  
  Specified by:
  
  getWorkDone in interface Worker<V>
  
  Returns:
  
  the amount of work done
  
  See Also:
  
  Worker.totalWorkProperty(), Worker.progressProperty()
- workDoneProperty
```
public final ReadOnlyDoubleProperty workDoneProperty()
```
  Description copied from interface: Worker
  
  Gets the ReadOnlyDoubleProperty representing the current progress.
  
  Specified by:
  
  workDoneProperty in interface Worker<V>
  
  Returns:
  
  The property representing the amount of work done
  
  See Also:
  
  getWorkDone()
- getTotalWork
```
public final double getTotalWork()
```
  Gets the value of the property totalWork.
  
  Specified by:
  
  getTotalWork in interface Worker<V>
  
  Returns:
  
  the total work to be done
  
  See Also:
  
  Worker.workDoneProperty(), Worker.progressProperty()
- totalWorkProperty
```
public final ReadOnlyDoubleProperty totalWorkProperty()
```
  Description copied from interface: Worker
  
  Gets the ReadOnlyDoubleProperty representing the maximum amount of work that needs to be done. These "work units" have meaning to the Worker implementation, such as the number of bytes that need to be downloaded or the number of images to process or some other such metric.
  
  Specified by:
  
  totalWorkProperty in interface Worker<V>
  
  Returns:
  
  the property representing the total work to be done
  
  See Also:
  
  getTotalWork()
- getProgress
```
public final double getProgress()
```
  Gets the value of the property progress.
  
  Specified by:
  
  getProgress in interface Worker<V>
  
  Returns:
  
  the current progress
  
  See Also:
  
  Worker.workDoneProperty(), Worker.totalWorkProperty()
- progressProperty
```
public final ReadOnlyDoubleProperty progressProperty()
```
  Description copied from interface: Worker
  
  Gets the ReadOnlyDoubleProperty representing the progress.
  
  Specified by:
  
  progressProperty in interface Worker<V>
  
  Returns:
  
  the property representing the progress
  
  See Also:
  
  getProgress()
- isRunning
```
public final boolean isRunning()
```
  Gets the value of the property running.
  
  Specified by:
  
  isRunning in interface Worker<V>
  
  Returns:
  
  true if this Worker is running
- runningProperty
```
public final ReadOnlyBooleanProperty runningProperty()
```
  Description copied from interface: Worker
  
  Gets the ReadOnlyBooleanProperty representing whether the Worker is running.
  
  Specified by:
  
  runningProperty in interface Worker<V>
  
  Returns:
  
  the property representing whether the worker is running
  
  See Also:
  
  isRunning()
- getMessage
```
public final String getMessage()
```
  Gets the value of the property message.
  
  Specified by:
  
  getMessage in interface Worker<V>
  
  Returns:
  
  the current message
- messageProperty
```
public final ReadOnlyStringProperty messageProperty()
```
  Description copied from interface: Worker
  
  Gets the ReadOnlyStringProperty representing the message.
  
  Specified by:
  
  messageProperty in interface Worker<V>
  
  Returns:
  
  a property representing the current message
  
  See Also:
  
  getMessage()
- getTitle
```
public final String getTitle()
```
  Gets the value of the property title.
  
  Specified by:
  
  getTitle in interface Worker<V>
  
  Returns:
  
  the current title
- titleProperty
```
public final ReadOnlyStringProperty titleProperty()
```
  Description copied from interface: Worker
  
  Gets the ReadOnlyStringProperty representing the title.
  
  Specified by:
  
  titleProperty in interface Worker<V>
  
  Returns:
  
  the property representing the current title
  
  See Also:
  
  getTitle()
- setExecutor
```
public final void setExecutor(Executor value)
```
  Sets the value of the property executor.
  
  Property description:
  
  The executor to use for running this Service. If no executor is specified, then a new daemon thread will be created and used for running the Service using some default executor.
- getExecutor
```
public final Executor getExecutor()
```
  Gets the value of the property executor.
  
  Property description:
  
  The executor to use for running this Service. If no executor is specified, then a new daemon thread will be created and used for running the Service using some default executor.
- executorProperty
```
public final ObjectProperty<Executor> executorProperty()
```
  The executor to use for running this Service. If no executor is specified, then a new daemon thread will be created and used for running the Service using some default executor.
  
  See Also:
  
  getExecutor(), setExecutor(Executor)
- onReadyProperty
```
public final ObjectProperty<EventHandler<WorkerStateEvent>> onReadyProperty()
```
  The onReady event handler is called whenever the Task state transitions to the READY state.
  
  Since:
  
  JavaFX 2.1
  
  See Also:
  
  getOnReady(), setOnReady(EventHandler)
- getOnReady
```
public final EventHandler<WorkerStateEvent> getOnReady()
```
  The onReady event handler is called whenever the Task state transitions to the READY state.
  
  Returns:
  
  the onReady event handler, if any
  
  Since:
  
  JavaFX 2.1
- setOnReady
```
public final void setOnReady(EventHandler<WorkerStateEvent> value)
```
  The onReady event handler is called whenever the Task state transitions to the READY state.
  
  Parameters:
  
  value - the event handler, can be null to clear it
  
  Since:
  
  JavaFX 2.1
- ready
```
protected void ready()
```
  A protected convenience method for subclasses, called whenever the state of the Service has transitioned to the READY state. This method is invoked after the Service has been fully transitioned to the new state.
  
  Since:
  
  JavaFX 2.1
- onScheduledProperty
```
public final ObjectProperty<EventHandler<WorkerStateEvent>> onScheduledProperty()
```
  The onSchedule event handler is called whenever the Task state transitions to the SCHEDULED state.
  
  Since:
  
  JavaFX 2.1
  
  See Also:
  
  getOnScheduled(), setOnScheduled(EventHandler)
- getOnScheduled
```
public final EventHandler<WorkerStateEvent> getOnScheduled()
```
  The onSchedule event handler is called whenever the Task state transitions to the SCHEDULED state.
  
  Returns:
  
  the onScheduled event handler, if any
  
  Since:
  
  JavaFX 2.1
- setOnScheduled
```
public final void setOnScheduled(EventHandler<WorkerStateEvent> value)
```
  The onSchedule event handler is called whenever the Task state transitions to the SCHEDULED state.
  
  Parameters:
  
  value - the event handler, can be null to clear it
  
  Since:
  
  JavaFX 2.1
- scheduled
```
protected void scheduled()
```
  A protected convenience method for subclasses, called whenever the state of the Service has transitioned to the SCHEDULED state. This method is invoked after the Service has been fully transitioned to the new state.
  
  Since:
  
  JavaFX 2.1
- onRunningProperty
```
public final ObjectProperty<EventHandler<WorkerStateEvent>> onRunningProperty()
```
  The onRunning event handler is called whenever the Task state transitions to the RUNNING state.
  
  Since:
  
  JavaFX 2.1
  
  See Also:
  
  getOnRunning(), setOnRunning(EventHandler)
- getOnRunning
```
public final EventHandler<WorkerStateEvent> getOnRunning()
```
  The onRunning event handler is called whenever the Task state transitions to the RUNNING state.
  
  Returns:
  
  the onRunning event handler, if any
  
  Since:
  
  JavaFX 2.1
- setOnRunning
```
public final void setOnRunning(EventHandler<WorkerStateEvent> value)
```
  The onRunning event handler is called whenever the Task state transitions to the RUNNING state.
  
  Parameters:
  
  value - the event handler, can be null to clear it
  
  Since:
  
  JavaFX 2.1
- running
```
protected void running()
```
  A protected convenience method for subclasses, called whenever the state of the Service has transitioned to the RUNNING state. This method is invoked after the Service has been fully transitioned to the new state.
  
  Since:
  
  JavaFX 2.1
- onSucceededProperty
```
public final ObjectProperty<EventHandler<WorkerStateEvent>> onSucceededProperty()
```
  The onSucceeded event handler is called whenever the Task state transitions to the SUCCEEDED state.
  
  Since:
  
  JavaFX 2.1
  
  See Also:
  
  getOnSucceeded(), setOnSucceeded(EventHandler)
- getOnSucceeded
```
public final EventHandler<WorkerStateEvent> getOnSucceeded()
```
  The onSucceeded event handler is called whenever the Task state transitions to the SUCCEEDED state.
  
  Returns:
  
  the onSucceeded event handler, if any
  
  Since:
  
  JavaFX 2.1
- setOnSucceeded
```
public final void setOnSucceeded(EventHandler<WorkerStateEvent> value)
```
  The onSucceeded event handler is called whenever the Task state transitions to the SUCCEEDED state.
  
  Parameters:
  
  value - the event handler, can be null to clear it
  
  Since:
  
  JavaFX 2.1
- succeeded
```
protected void succeeded()
```
  A protected convenience method for subclasses, called whenever the state of the Service has transitioned to the SUCCEEDED state. This method is invoked after the Service has been fully transitioned to the new state.
  
  Since:
  
  JavaFX 2.1
- onCancelledProperty
```
public final ObjectProperty<EventHandler<WorkerStateEvent>> onCancelledProperty()
```
  The onCancelled event handler is called whenever the Task state transitions to the CANCELLED state.
  
  Since:
  
  JavaFX 2.1
  
  See Also:
  
  getOnCancelled(), setOnCancelled(EventHandler)
- getOnCancelled
```
public final EventHandler<WorkerStateEvent> getOnCancelled()
```
  The onCancelled event handler is called whenever the Task state transitions to the CANCELLED state.
  
  Returns:
  
  the onCancelled event handler, if any
  
  Since:
  
  JavaFX 2.1
- setOnCancelled
```
public final void setOnCancelled(EventHandler<WorkerStateEvent> value)
```
  The onCancelled event handler is called whenever the Task state transitions to the CANCELLED state.
  
  Parameters:
  
  value - the event handler, can be null to clear it
  
  Since:
  
  JavaFX 2.1
- cancelled
```
protected void cancelled()
```
  A protected convenience method for subclasses, called whenever the state of the Service has transitioned to the CANCELLED state. This method is invoked after the Service has been fully transitioned to the new state.
  
  Since:
  
  JavaFX 2.1
- onFailedProperty
```
public final ObjectProperty<EventHandler<WorkerStateEvent>> onFailedProperty()
```
  The onFailed event handler is called whenever the Task state transitions to the FAILED state.
  
  Since:
  
  JavaFX 2.1
  
  See Also:
  
  getOnFailed(), setOnFailed(EventHandler)
- getOnFailed
```
public final EventHandler<WorkerStateEvent> getOnFailed()
```
  The onFailed event handler is called whenever the Task state transitions to the FAILED state.
  
  Returns:
  
  the onFailed event handler, if any
  
  Since:
  
  JavaFX 2.1
- setOnFailed
```
public final void setOnFailed(EventHandler<WorkerStateEvent> value)
```
  The onFailed event handler is called whenever the Task state transitions to the FAILED state.
  
  Parameters:
  
  value - the event handler, can be null to clear it
  
  Since:
  
  JavaFX 2.1
- failed
```
protected void failed()
```
  A protected convenience method for subclasses, called whenever the state of the Service has transitioned to the FAILED state. This method is invoked after the Service has been fully transitioned to the new state.
  
  Since:
  
  JavaFX 2.1
- cancel
```
public boolean cancel()
```
  Cancels any currently running Task, if any. The state will be set to CANCELLED.
  
  Specified by:
  
  cancel in interface Worker<V>
  
  Returns:
  
  returns true if the cancel was successful
- restart
```
public void restart()
```
  Cancels any currently running Task, if any, and restarts this Service. The state will be reset to READY prior to execution. This method should only be called on the FX application thread.
- reset
```
public void reset()
```
  Resets the Service. May only be called while in one of the finish states, that is, SUCCEEDED, FAILED, or CANCELLED, or when READY. This method should only be called on the FX application thread.
- start
```
public void start()
```
  Starts this Service. The Service must be in the READY state to succeed in this call. This method should only be called on the FX application thread.
- executeTask
```
protected void executeTask(Task<V> task)
```
  Uses the executor defined on this Service to execute the given task. If the executor is null, then a default executor is used which will create a new daemon thread on which to execute this task.
  
  This method is intended only to be called by the Service implementation.
  
  Parameters:
  
  task - a non-null task to execute
  
  Since:
  
  JavaFX 2.1
- addEventHandler
```
public final <T extends Event> void addEventHandler(EventType<T> eventType,
                                                    EventHandler<? super T> eventHandler)
```
  Registers an event handler to this task. Any event filters are first processed, then the specified onFoo event handlers, and finally any event handlers registered by this method. As with other events in the scene graph, if an event is consumed, it will not continue dispatching.
  
  Type Parameters:
  
  T - the specific event class of the handler
  
  Parameters:
  
  eventType - the type of the events to receive by the handler
  
  Throws:
  
  NullPointerException - if the event type or handler is null
  
  Since:
  
  JavaFX 2.1
- removeEventHandler
```
public final <T extends Event> void removeEventHandler(EventType<T> eventType,
                                                       EventHandler<? super T> eventHandler)
```
  Unregisters a previously registered event handler from this task. One handler might have been registered for different event types, so the caller needs to specify the particular event type from which to unregister the handler.
  
  Type Parameters:
  
  T - the specific event class of the handler
  
  Parameters:
  
  eventType - the event type from which to unregister
  
  Throws:
  
  NullPointerException - if the event type or handler is null
  
  Since:
  
  JavaFX 2.1
- addEventFilter
```
public final <T extends Event> void addEventFilter(EventType<T> eventType,
                                                   EventHandler<? super T> eventFilter)
```
  Registers an event filter to this task. Registered event filters get an event before any associated event handlers.
  
  Type Parameters:
  
  T - the specific event class of the filter
  
  Parameters:
  
  eventType - the type of the events to receive by the filter
  
  Throws:
  
  NullPointerException - if the event type or filter is null
  
  Since:
  
  JavaFX 2.1
- removeEventFilter
```
public final <T extends Event> void removeEventFilter(EventType<T> eventType,
                                                      EventHandler<? super T> eventFilter)
```
  Unregisters a previously registered event filter from this task. One filter might have been registered for different event types, so the caller needs to specify the particular event type from which to unregister the filter.
  
  Type Parameters:
  
  T - the specific event class of the filter
  
  Parameters:
  
  eventType - the event type from which to unregister
  
  Throws:
  
  NullPointerException - if the event type or filter is null
  
  Since:
  
  JavaFX 2.1
- setEventHandler
```
protected final <T extends Event> void setEventHandler(EventType<T> eventType,
                                                       EventHandler<? super T> eventHandler)
```
  Sets the handler to use for this event type. There can only be one such handler specified at a time. This handler is guaranteed to be called first. This is used for registering the user-defined onFoo event handlers.
  
  Type Parameters:
  
  T - the specific event class of the handler
  
  Parameters:
  
  eventType - the event type to associate with the given eventHandler
  
  Throws:
  
  NullPointerException - if the event type is null
  
  Since:
  
  JavaFX 2.1
- fireEvent
```
protected final void fireEvent(Event event)
```
  Fires the specified event. Any event filter encountered will be notified and can consume the event. If not consumed by the filters, the event handlers on this task are notified. If these don't consume the event either, then all event handlers are called and can consume the event.
  This method must be called on the FX user thread.
  
  Parameters:
  
  event - the event to fire
  
  Since:
  
  JavaFX 2.1
- buildEventDispatchChain
```
public EventDispatchChain buildEventDispatchChain(EventDispatchChain tail)
```
  Description copied from interface: EventTarget
  
  Construct an event dispatch chain for this target. The event dispatch chain contains event dispatchers which might be interested in processing of events targeted at this EventTarget. This event target is not automatically added to the chain, so if it wants to process events, it needs to add an EventDispatcher for itself to the chain.
  In the case the event target is part of some hierarchy, the chain for it is usually built from event dispatchers collected from the root of the hierarchy to the event target.
  
  The event dispatch chain is constructed by modifications to the provided initial event dispatch chain. The returned chain should have the initial chain at its end so the dispatchers should be prepended to the initial chain.
  
  The caller shouldn't assume that the initial chain remains unchanged nor that the returned value will reference a different chain.
  
  Specified by:
  
  buildEventDispatchChain in interface EventTarget
  
  Parameters:
  
  tail - the initial chain to build from
  
  Returns:
  
  the resulting event dispatch chain for this target
- createTask
```
protected abstract Task<V> createTask()
```
  Invoked after the Service is started on the JavaFX Application Thread. Implementations should save off any state into final variables prior to creating the Task, since accessing properties defined on the Service within the background thread code of the Task will result in exceptions. For example:
```
protected Task createTask() {
         final String url = myService.getUrl();
         return new Task<String>() {
             protected String call() {
                 URL u = new URL("http://www.oracle.com");
                 BufferedReader in = new BufferedReader(
                         new InputStreamReader(u.openStream()));
                 String result = in.readLine();
                 in.close();
                 return result;
             }
         }
     }
```
  If the Task is a pre-defined class (as opposed to being an anonymous class), and if it followed the recommended best-practice, then there is no need to save off state prior to constructing the Task since its state is completely provided in its constructor.
```
protected Task createTask() {
         // This is safe because getUrl is called on the FX Application
         // Thread and the FirstLineReaderTasks stores it as an
         // immutable property
         return new FirstLineReaderTask(myService.getUrl());
     }
```
  Returns:
  
  the Task to execute

© 2008, 2025, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from JavaFX API Documentation.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Java, JavaFX and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.

Class Service<V>

Property Summary

Nested Class Summary

Nested classes/interfaces inherited from interface javafx.concurrent.Worker

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Property Detail

state

value

exception

workDone

totalWork

progress

running

message

title

executor

onReady

onScheduled

onRunning

onSucceeded

onCancelled

onFailed

Constructor Detail

Service

Method Detail

getState

stateProperty

getValue

valueProperty

getException

exceptionProperty

getWorkDone

workDoneProperty

getTotalWork

totalWorkProperty

getProgress

progressProperty

isRunning

runningProperty

getMessage

messageProperty

getTitle

titleProperty

setExecutor

getExecutor

executorProperty

onReadyProperty

getOnReady

setOnReady

ready

onScheduledProperty

getOnScheduled

setOnScheduled

scheduled

onRunningProperty

getOnRunning

setOnRunning

running

onSucceededProperty

getOnSucceeded

setOnSucceeded

succeeded

onCancelledProperty

getOnCancelled

setOnCancelled

cancelled

onFailedProperty

getOnFailed

setOnFailed

failed

cancel

restart

reset

start

executeTask

addEventHandler

removeEventHandler

addEventFilter