oracle.jdeveloper.usage.util

Interface BackgroundTask

All Known Subinterfaces:

UsageQueryTask

All Known Implementing Classes:

AbstractBackgroundTask, TaskMultiplexer.TaskWrapper

public interface BackgroundTask

The BackgroundTask is an interface that describes the operations available for checking on the status of a running task. There are methods available for checking if the task is finished, if the task was successfully completed, and for cancelling the task. Query implementations may extend this interface to provide an interface method for fetching the resultant query data.

Method Summary

Methods

Modifier and Type	Method and Description
void	cancel() Attempts to cancel the current task in progress.
int	getProgress() Fetches the current progress of the query task.
java.lang.String	getProgressText() Fetches a human-readable (translated) descriptive text that describes what the task is currently doing.
boolean	isFinished() Fetch whether this task is completed or not.
void	waitUntilFinished() Waits until the task is finished (i.e., isFinished() returns true).

Method Detail

isFinished

boolean isFinished()

Fetch whether this task is completed or not. Returns true if this task was completed (sucessful or failed with exception) or cancelled, or false if the task is still running or has not been started yet.

Returns:

true if the task is finished or cancelled, false otherwise

waitUntilFinished

void waitUntilFinished()

Waits until the task is finished (i.e., isFinished() returns true). This will block the current thread.

cancel

void cancel()

Attempts to cancel the current task in progress. This does not guarantee the task will be cancelled immediately, as it is implementation dependent, though implementations are strongly encouraged to ensure a speedy cancellation. Clients should not fetch or use the query results when a cancel is issued, as the results are unpredictable.

getProgress

int getProgress()

Fetches the current progress of the query task. This will return an integer between 0 (just started) and 100 (finished). This is solely an estimate, and is not guaranteed to be accurate, though implementations are encouraged to try to provide an accurate number. This can be used by clients to display a progress bar for example.

Returns:

a progress value between 0 and 100 to denote the running status of this task

getProgressText

java.lang.String getProgressText()

Fetches a human-readable (translated) descriptive text that describes what the task is currently doing. Implementations should try to make this information actually usable and informative for users. This can be used by clients to display with a progress bar for example.

Returns:

a human-readable description of the current task's progress