au.com.cybersearch2.classytask

Class BackgroundTask

java.lang.Object

au.com.cybersearch2.classytask.BackgroundTask

All Implemented Interfaces:

Callable<Boolean>

public abstract class BackgroundTask
extends Object
implements Callable<Boolean>

BackgroundTask

Author:

Andrew Bowley 8 Jan 2016

Constructor Summary

Constructors

Constructor and Description
BackgroundTask(ThreadHelper threadHelper) Construct BackgroundTask object

Method Summary

Modifier and Type	Method and Description
Boolean	call() Start task on background thread
abstract boolean	doInBackground() Override this method to perform a computation on a background thread.
ExecutionException	getExecutionException() Returns Exception thrown when the worker task fails due to a uncaught RuntimeException
void	onCancelled(Boolean result) Runs on separate thread after TaskRunner.cancel(boolean) is invoked.
void	onPostExecute(Boolean result) Runs on the UI thread after doInBackground().
void	onPreExecute() Runs on the UI thread before doInBackground().
void	setExecutionException(ExecutionException executionException) Set Exception thrown when the worker task fails due to a uncaught RuntimeException

Methods inherited from class java.lang.Object

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

Constructor Detail

BackgroundTask

public BackgroundTask(ThreadHelper threadHelper)

Construct BackgroundTask object

Parameters:

threadHelper - ThreadHelper allows thread priority adjustment

Method Detail

doInBackground

public abstract boolean doInBackground()

Override this method to perform a computation on a background thread. Any required parameters will need to be provided as fields belonging to the sub class.

Returns:

Boolean object to flag success (true), failure (false) or cancel (null)

See Also:

onPreExecute(), onPostExecute(Boolean)

onPreExecute

public void onPreExecute()

Runs on the UI thread before doInBackground().

See Also:

onPostExecute(Boolean), doInBackground()

onPostExecute

public void onPostExecute(Boolean result)

Runs on the UI thread after doInBackground(). The specified result is the value returned by doInBackground() or null if the task was cancelled or an exception occured.

Parameters:

result - The result of the operation computed by doInBackground().

See Also:

onPreExecute(), doInBackground()

onCancelled

public void onCancelled(Boolean result)

Runs on separate thread after TaskRunner.cancel(boolean) is invoked.

Parameters:

result - The result of the operation computed by doInBackground().

See Also:

TaskRunner.cancel(boolean), TaskRunner.isCancelled()

call

public Boolean call()
             throws Exception

Start task on background thread

Specified by:

call in interface Callable<Boolean>

Throws:

Exception

See Also:

Callable.call()

setExecutionException

public void setExecutionException(ExecutionException executionException)

Set Exception thrown when the worker task fails due to a uncaught RuntimeException

Parameters:

executionException - ExecutionException

getExecutionException

public ExecutionException getExecutionException()

Returns Exception thrown when the worker task fails due to a uncaught RuntimeException

Returns:

ExecutionException