foxtrot

Class AsyncTask

java.lang.Object

foxtrot.Task

foxtrot.AsyncTask

public abstract class AsyncTask
extends Task

A time-consuming task to be executed asynchronously by AsyncWorker.
Users must implement the Task.run() method as they would do with Task.
Exceptions and Errors thrown by the run() method will not be rethrown automatically by AsyncWorker.post(AsyncTask).
Instead, two callbacks are provided to handle the successful run of the task or its failure, respectively success(Object) and failure(Throwable), both called in the Event Dispatch Thread when the task is finished.
AsyncTasks cannot be reused, that is, it is not safe to pass the same instance to two consecutive calls to AsyncWorker.post(AsyncTask).
Example:

 AsyncTask task = new AsyncTask()
 {
     public Object run() throws Exception
     {
         // Called in a worker thread
         Thread.sleep(1000);
         return new ArrayList();
     }

     public void success(Object result)
     {
         // Called in the Event Dispatch Thread
         List result = (List)result;
         // Do something with the List
     }
     public void failure(Throwable x)
     {
         // Report exception to the user, or just log it
     }
 });
 

Version:

$Revision: 260 $

See Also:

AsyncWorker

Constructor Summary

Constructors

Constructor and Description
AsyncTask()

Method Summary

Methods

Modifier and Type	Method and Description
abstract void	failure(Throwable x) Callback called in the Event Dispatch Thread in case of exception thrown during the execution of this AsyncTask.
protected void	finish() Called in the Event Dispatch Thread after this AsyncTask is finished.
abstract void	success(Object result) Callback called in the Event Dispatch Thread in case of successful execution of this AsyncTask.

Methods inherited from class foxtrot.Task

getResultOrThrow, isCompleted, run

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AsyncTask

public AsyncTask()

Method Detail

finish

protected void finish()

Called in the Event Dispatch Thread after this AsyncTask is finished.
Normally there is no need to override this method, as it forwards the result of the task run to success(Object) in case the task ran successfully, or to failure(Throwable) in case the task did not complete successfully.
When this method is overridden, a call to Task.getResultOrThrow() must be done to retrieve the result of the task, or to rethrow the exception thrown by the task.

See Also:

success(Object), failure(Throwable), Task.getResultOrThrow()

success

public abstract void success(Object result)

Callback called in the Event Dispatch Thread in case of successful execution of this AsyncTask.

Parameters:

result - The result of the task execution, as returned from Task.run()

failure

public abstract void failure(Throwable x)

Callback called in the Event Dispatch Thread in case of exception thrown during the execution of this AsyncTask.

Parameters:

x - The Throwable thrown during the task execution.