com.barchart.util.concurrent
Interface FutureCallback<V,T extends FutureCallback<V,T>>

Type Parameters:

E - The result type

All Superinterfaces:

Future<V>

All Known Implementing Classes:

CancellableFutureNotifier, FutureCallbackList, FutureCallbackTask, FutureNotifier, FutureNotifierBase

public interface FutureCallback<V,T extends FutureCallback<V,T>>
extends Future<V>

Adds listener notification methods to Future to allow immediate notification when a result is available.

Example:

 FutureListener<Employee> listener = new FutureListener<Employee> {
   public void resultAvailable(Future<Employee> result) {
     System.out.println("Got deferred result: " + result.get());
   }
 }
 
 FutureCallback<Employee> result = myDataStore.getEmployee(id);
 result.addResultListener(listener);
 

In this example, getEmployee() returns a FutureCallback object that it will later use to return a result asynchronously. When it has a result, it calls result.succeed(Employee e), which in turn notifies any listeners registered with result.addResultListener(). If the call fails, the owner may call result.fail(Exception ex) to report the error. If a FutureCallback has failed, any future calls to result.get() throw an ExecutionException with the original exception as its cause.

This class is thread-safe.

Author:

jeremy

See Also:

Future, FutureListener, FutureCallbackTask

Method Summary

T	addResultListener(FutureListener<V> listener) Register a listener for this deferred result.
T	fail(Throwable error) Notify listeners that an error occurred.
V	getUnchecked() Get the return value, or null if a checked exception was caught.
T	succeed(V result) Notify listeners that a result is available.

Methods inherited from interface java.util.concurrent.Future

cancel, get, get, isCancelled, isDone

Method Detail

addResultListener

T addResultListener(FutureListener<V> listener)

Register a listener for this deferred result. If the result is already available, the listener may be called synchronously, so you should generally avoid any blocking code in the callback.

Parameters:

listener - The listener object

succeed

T succeed(V result)

Notify listeners that a result is available. Returns the current FutureCallbackTask instance to allow simple synchronous returns when the result is already available:
return new FutureCallbackTask