Task

public abstract class Task extends Object

Known Direct Subclasses CancellableTask<TState> CancellableTask<TState> Represents an asynchronous operation that can be canceled.

Known Indirect Subclasses ControllableTask<TState>, FileDownloadTask, StorageTask<TResult extends StorageTask.ProvideError>, StreamDownloadTask, UploadTask ControllableTask<TState> Represents an asynchronous operation that can be paused, resumed and canceled.  FileDownloadTask A task that downloads bytes of a GCS blob to a specified File.  StorageTask<TResult extends StorageTask.ProvideError> A controllable Task that has a synchronized state machine.  StreamDownloadTask A task that downloads bytes of a GCS blob.  UploadTask An controllable task that uploads and fires events for success, progress and failure.

Represents an asynchronous operation.

Public Constructor Summary

Task()

Public Method Summary

Task<TResult>	addOnCompleteListener(OnCompleteListener<TResult> listener) Adds a listener that is called when the Task completes.
Task<TResult>	addOnCompleteListener(Activity activity, OnCompleteListener<TResult> listener) Adds an Activity-scoped listener that is called when the Task completes.
Task<TResult>	addOnCompleteListener(Executor executor, OnCompleteListener<TResult> listener) Adds a listener that is called when the Task completes.
abstract Task<TResult>	addOnFailureListener(Activity activity, OnFailureListener listener) Adds an Activity-scoped listener that is called if the Task fails.
abstract Task<TResult>	addOnFailureListener(OnFailureListener listener) Adds a listener that is called if the Task fails.
abstract Task<TResult>	addOnFailureListener(Executor executor, OnFailureListener listener) Adds a listener that is called if the Task fails.
abstract Task<TResult>	addOnSuccessListener(Executor executor, OnSuccessListener<? super TResult> listener) Adds a listener that is called if the Task completes successfully.
abstract Task<TResult>	addOnSuccessListener(OnSuccessListener<? super TResult> listener) Adds a listener that is called if the Task completes successfully.
abstract Task<TResult>	addOnSuccessListener(Activity activity, OnSuccessListener<? super TResult> listener) Adds an Activity-scoped listener that is called if the Task completes successfully.
<TContinuationResult> Task<TContinuationResult>	continueWith(Continuation<TResult, TContinuationResult> continuation) Returns a new Task that will be completed with the result of applying the specified Continuation to this Task.
<TContinuationResult> Task<TContinuationResult>	continueWith(Executor executor, Continuation<TResult, TContinuationResult> continuation) Returns a new Task that will be completed with the result of applying the specified Continuation to this Task.
<TContinuationResult> Task<TContinuationResult>	continueWithTask(Continuation<TResult, Task<TContinuationResult>> continuation) Returns a new Task that will be completed with the result of applying the specified Continuation to this Task.
<TContinuationResult> Task<TContinuationResult>	continueWithTask(Executor executor, Continuation<TResult, Task<TContinuationResult>> continuation) Returns a new Task that will be completed with the result of applying the specified Continuation to this Task.
abstract Exception	getException() Returns the exception that caused the Task to fail.
abstract Result	getResult() Gets the result of the Task, if it has already completed.
abstract <X extends Throwable> Result	getResult(Class<X> exceptionType) Gets the result of the Task, if it has already completed.
abstract boolean	isComplete() Returns true if the Task is complete; false otherwise.
abstract boolean	isSuccessful() Returns true if the Task has completed successfully; false otherwise.

Inherited Method Summary

From class java.lang.Object

Object	clone()
boolean	equals(Object arg0)
void	finalize()
final Class<?>	getClass()
int	hashCode()
final void	notify()
final void	notifyAll()
String	toString()
final void	wait(long arg0, int arg1)
final void	wait(long arg0)
final void	wait()

Public Constructors

public Task ()

Public Methods

public Task<TResult> addOnCompleteListener (OnCompleteListener<TResult> listener)

Adds a listener that is called when the Task completes.

The listener will be called on main application thread. If the Task is already complete, a call to the listener will be immediately scheduled. If multiple listeners are added, they will be called in the order in which they were added.

Returns

• this Task

public Task<TResult> addOnCompleteListener (Activity activity, OnCompleteListener<TResult> listener)

Adds an Activity-scoped listener that is called when the Task completes.

The listener will be called on main application thread. If the Task is already complete, a call to the listener will be immediately scheduled. If multiple listeners are added, they will be called in the order in which they were added.

The listener will be automatically removed during onStop().

Returns

• this Task

public Task<TResult> addOnCompleteListener (Executor executor, OnCompleteListener<TResult> listener)

Adds a listener that is called when the Task completes.

If the Task is already complete, a call to the listener will be immediately scheduled. If multiple listeners are added, they will be called in the order in which they were added.

Parameters

executor	the executor to use to call the listener
listener

Returns

• this Task

public abstract Task<TResult> addOnFailureListener (Activity activity, OnFailureListener listener)

Adds an Activity-scoped listener that is called if the Task fails.

The listener will be called on main application thread. If the Task has already failed, a call to the listener will be immediately scheduled. If multiple listeners are added, they will be called in the order in which they were added.

The listener will be automatically removed during onStop().

Returns

• this Task

public abstract Task<TResult> addOnFailureListener (OnFailureListener listener)

Adds a listener that is called if the Task fails.

The listener will be called on main application thread. If the Task has already failed, a call to the listener will be immediately scheduled. If multiple listeners are added, they will be called in the order in which they were added.

Returns

• this Task

public abstract Task<TResult> addOnFailureListener (Executor executor, OnFailureListener listener)

Adds a listener that is called if the Task fails.

If the Task has already failed, a call to the listener will be immediately scheduled. If multiple listeners are added, they will be called in the order in which they were added.

Parameters

executor	the executor to use to call the listener
listener

Returns

• this Task

public abstract Task<TResult> addOnSuccessListener (Executor executor, OnSuccessListener<? super TResult> listener)

Adds a listener that is called if the Task completes successfully.

If multiple listeners are added, they will be called in the order in which they were added. If the Task has already completed successfully, a call to the listener will be immediately scheduled.

Parameters

executor	the executor to use to call the listener
listener

Returns

• this Task

public abstract Task<TResult> addOnSuccessListener (OnSuccessListener<? super TResult> listener)

Adds a listener that is called if the Task completes successfully.

The listener will be called on the main application thread. If the Task has already completed successfully, a call to the listener will be immediately scheduled. If multiple listeners are added, they will be called in the order in which they were added.

Returns

• this Task

public abstract Task<TResult> addOnSuccessListener (Activity activity, OnSuccessListener<? super TResult> listener)

Adds an Activity-scoped listener that is called if the Task completes successfully.

The listener will be called on the main application thread. If the Task has already completed successfully, a call to the listener will be immediately scheduled. If multiple listeners are added, they will be called in the order in which they were added.

The listener will be automatically removed during onStop().

Returns

• this Task

public Task<TContinuationResult> continueWith (Continuation<TResult, TContinuationResult> continuation)

Returns a new Task that will be completed with the result of applying the specified Continuation to this Task.

The Continuation will be called on the main application thread.

See Also

• then(Task)

public Task<TContinuationResult> continueWith (Executor executor, Continuation<TResult, TContinuationResult> continuation)

Returns a new Task that will be completed with the result of applying the specified Continuation to this Task.

Parameters

executor	the executor to use to call the Continuation
continuation

See Also

• then(Task)

public Task<TContinuationResult> continueWithTask (Continuation<TResult, Task<TContinuationResult>> continuation)

Returns a new Task that will be completed with the result of applying the specified Continuation to this Task.

The Continuation will be called on the main application thread.

See Also

• then(Task)

public Task<TContinuationResult> continueWithTask (Executor executor, Continuation<TResult, Task<TContinuationResult>> continuation)

Returns a new Task that will be completed with the result of applying the specified Continuation to this Task.

Parameters

executor	the executor to use to call the Continuation
continuation

See Also

• then(Task)

public abstract Exception getException ()

Returns the exception that caused the Task to fail. Returns null if the Task is not yet complete, or completed successfully.

public abstract TResult getResult ()

Gets the result of the Task, if it has already completed.

Throws

IllegalStateException	if the Task is not yet complete
RuntimeExecutionException	if the Task failed with an exception

public abstract TResult getResult (Class<X> exceptionType)

Gets the result of the Task, if it has already completed.

Throws

IllegalStateException	if the Task is not yet complete
	if the Task failed with an exception of type X
RuntimeExecutionException	if the Task failed with an exception that was not of type X
Throwable

public abstract boolean isComplete ()

Returns true if the Task is complete; false otherwise.

public abstract boolean isSuccessful ()

Returns true if the Task has completed successfully; false otherwise.