SettableFuture (FoundationDB Java Client API)

java.lang.Object
- com.foundationdb.async.AbstractPartialFuture<T>
- - com.foundationdb.async.AbstractFuture<T>
  - - com.foundationdb.async.SettableFuture<T>

Type Parameters:
T - the output type of a successful process

All Implemented Interfaces:

Cancellable, Future<T>, PartialFuture<T>, Settable<T>, Disposable
```
public class SettableFuture<T>
extends AbstractFuture<T>
implements Settable<T>
```
Represents an Future that can be fulfilled via the Settable interface. SettableFuture has a default Executor that is used when a SettableFuture is created without passing this parameter, which runs callback functions immediately on the stack when the future is fulfilled.

See Also:
ReadyFuture

Constructor Summary

Constructors
Constructor and Description
`SettableFuture()` Construct a `SettableFuture` with the default `Executor`
`SettableFuture(Executor executor)` Construct a `SettableFuture` with a specified `Executor`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`blockInterruptibly()` Blocks until this `Future` is set to either a value or an error.
`void`	`blockUntilReady()` Blocks until this `Future` is set to either a value or an error.
`void`	`cancel()` Cancels this operation or signal.
`Throwable`	`getError()` Gets the error from a `Future` if it has been set to this state.
`T`	`getIfDone()` Gets the value from this `Future`.
`boolean`	`isDone()` Gets the readiness of this `Future`.
`boolean`	`isError()` Tests if this `Future` is set to an error
`boolean`	`isSet()` Returns `true` if this `Settable` has been set to a value or error.
`boolean`	`onCancelled(Runnable r)` Register code to be called if this operation is cancelled.
`void`	`onCancelledCancel(Cancellable c)` Link an operation to cancel in the event that this `Settable` is cancelled.
`void`	`set(T value)` Set this `Settable` to a value.
`void`	`setError(Error error)` Set this `Settable` to an error.
`void`	`setError(RuntimeException error)` Set this `Settable` to an error.

Methods inherited from class com.foundationdb.async.AbstractFuture
flatMap, get, getInterruptibly, map, rescueRuntime

Methods inherited from class com.foundationdb.async.AbstractPartialFuture
dispose, flatMap, map, onReady, onReadyAlready, rescue, rescue

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

Methods inherited from interface com.foundationdb.async.PartialFuture
dispose, flatMap, map, onReady, onReadyAlready, rescue, rescue

- Constructor Detail
  - SettableFuture
```
public SettableFuture()
```
    Construct a SettableFuture with the default Executor
  - SettableFuture
```
public SettableFuture(Executor executor)
```
    Construct a SettableFuture with a specified Executor
    
    Parameters:
    executor - the Executor with which to execute callbacks
- Method Detail
  - set
```
public void set(T value)
```
    Description copied from interface: Settable
    
    Set this Settable to a value. This will invoke callbacks, and unblock all Threads waiting on associated Futures. A Settable can be set only once and this call will throw an exception if this object is already set to a value or error. It is not, however, an error to call this if the operation has been cancelled. If the task has been cancelled, this call will have no effect.
    
    Specified by:
    
    set in interface Settable<T>
    
    Parameters:
    value - the output of this successful process
  - setError
```
public void setError(Error error)
```
    Description copied from interface: Settable
    
    Set this Settable to an error. This call will invoke callbacks, and unblock all Threads waiting on associated Futures. A Settable can be set only once and this call will throw an exception if this object is already set to a value or error. It is not, however, an error to call this method if the operation has been cancelled. If the task has been cancelled, this call will have no effect.
    
    Specified by:
    
    setError in interface Settable<T>
    
    Parameters:
    error - the error encountered in the course of this process
  - setError
```
public void setError(RuntimeException error)
```
    Description copied from interface: Settable
    
    Set this Settable to an error. This call will invoke callbacks, and unblock all Threads waiting on associated Futures. A Settable can be set only once and this call will throw an exception if this object is already set to a value or error. It is not, however, an error to call this method if the operation has been cancelled. If the task has been cancelled, this call will have no effect.
    
    Specified by:
    
    setError in interface Settable<T>
    
    Parameters:
    error - the error encountered in the course of this process
  - cancel
```
public void cancel()
```
    Description copied from interface: Cancellable
    
    Cancels this operation or signal. This will end the work that would have been done and notify all consumers of the operation that a result will not be returned. It is not an error to call this method on an operation that has already completed or already been cancelled. This method will not block or throw non-fatal exceptions.
    
    Specified by:
    
    cancel in interface Cancellable
    
    Specified by:
    
    cancel in interface PartialFuture<T>
  - isSet
```
public boolean isSet()
```
    Description copied from interface: Settable
    
    Returns true if this Settable has been set to a value or error.
    
    Specified by:
    
    isSet in interface Settable<T>
    
    Returns:
    true if a value or error has been set, false otherwise
  - onCancelled
```
public boolean onCancelled(Runnable r)
```
    Description copied from interface: Settable
    
    Register code to be called if this operation is cancelled. Settables can be cancelled by calls to PartialFuture.cancel() on associated Futures. If this Settable is already set, the callback will not be registered and this call will return false. If this call returns true the registered callback is guaranteed to be called if the associated Future is cancelled.
    
    Specified by:
    
    onCancelled in interface Settable<T>
    
    Parameters:
    r - routine to execute if cancelled.
    
    Returns:
    true if the callback was registered, false otherwise.
  - onCancelledCancel
```
public void onCancelledCancel(Cancellable c)
```
    Description copied from interface: Settable
    
    Link an operation to cancel in the event that this Settable is cancelled. This is a convenience method (for more complicated calls to Settable.onCancelled(Runnable)) with possible internal optimizations.
    
    Specified by:
    
    onCancelledCancel in interface Settable<T>
    
    Parameters:
    c - the operation to cancel
  - getIfDone
```
public T getIfDone()
```
    Description copied from class: AbstractPartialFuture
    
    Gets the value from this Future. It must be in the ready and non-error state. This is a non-blocking call. If this Future is set to an error get() throws this error.
    
    Returns:
    the value to which this Future has been set.
  - blockInterruptibly
```
public void blockInterruptibly()
                        throws InterruptedException
```
    Description copied from interface: PartialFuture
    
    Blocks until this Future is set to either a value or an error. When this function returns without an error, PartialFuture.isDone() will return true.
    Code should never block for a future to become ready in code invoked as a callback. Blocking in callback code will generally block client networking and cause a deadlock.
    
    Specified by:
    
    blockInterruptibly in interface PartialFuture<T>
    
    Throws:
    
    InterruptedException - if the blocked thread is interrupted
  - blockUntilReady
```
public void blockUntilReady()
```
    Description copied from interface: PartialFuture
    
    Blocks until this Future is set to either a value or an error. When this function returns without an error, PartialFuture.isDone() will return true.
    Code should never block for a future to become ready in code invoked as a callback. Blocking in callback code will generally block client networking and cause a deadlock.
    
    Specified by:
    
    blockUntilReady in interface PartialFuture<T>
  - isDone
```
public boolean isDone()
```
    Description copied from interface: PartialFuture
    
    Gets the readiness of this Future. A Future is ready if the value has been set or an error has been set.
    
    Specified by:
    
    isDone in interface PartialFuture<T>
    
    Returns:
    true if the Future is set to a value or error
  - isError
```
public boolean isError()
```
    Description copied from interface: PartialFuture
    
    Tests if this Future is set to an error
    
    Specified by:
    
    isError in interface PartialFuture<T>
    
    Returns:
    true if in error state, false otherwise
  - getError
```
public Throwable getError()
```
    Description copied from interface: Future
    
    Gets the error from a Future if it has been set to this state. If this Future is not yet set, or has not been set to an error, throws an exception. Although this method returns a Throwable, the set of possible return types is more limited. A Future is limited to being set to an unchecked exceptions -- that is an Error or a RuntimeException (or one of its subclasses).
    
    Specified by:
    
    getError in interface Future<T>
    
    Specified by:
    
    getError in interface PartialFuture<T>
    
    Returns:
    the error output of the Future

Class SettableFuture<T>

Constructor Summary

Method Summary

Methods inherited from class com.foundationdb.async.AbstractFuture

Methods inherited from class com.foundationdb.async.AbstractPartialFuture

Methods inherited from class java.lang.Object

Methods inherited from interface com.foundationdb.async.PartialFuture

Constructor Detail

SettableFuture

SettableFuture

Method Detail

set

setError

setError

cancel

isSet

onCancelled

onCancelledCancel

getIfDone

blockInterruptibly

blockUntilReady

isDone

isError

getError