org.netbeans.api.extexecution.base.input

Class InputReaderTask

java.lang.Object

org.netbeans.api.extexecution.base.input.InputReaderTask

All Implemented Interfaces:

Runnable, Cancellable

public final class InputReaderTask
extends Object
implements Runnable, Cancellable

Task consuming data from the certain reader, processing them with the given processor.

When exception occurs while the task is running the task is terminated. Task is responsive to interruption. InputReader is closed on finish (includes both cases throwing an exception and interruption).

The InputReaderTask.run() method can be executed just once.

Task is not finished implicitly by reaching the end of the reader. The caller has to finish it either by interruption or explicit cancellation. Cancellation is preferred in situations where the interruption could make cleanup operations on InputProcessor impossible to happen.

Sample usage - reading standard output of the process (throwing the data away):

     java.lang.Process process = ...
     java.util.concurrent.ExecutorService executorService = ...
     Runnable runnable = InputReaderTask.newTask(
         InputReaders.forStream(process.getInputStream(), Charset.defaultCharset()));
     executorService.submit(runnable);

     ...

     executorService.shutdownNow();
 

Sample usage - forwarding data to standard input of the process:

     java.lang.Process process = ...
     java.util.concurrent.ExecutorService executorService = ...
     Runnable runnable = InputReaderTask.newTask(
         InputReaders.forStream(System.in, Charset.defaultCharset()),
         InputProcessors.copying(new OutputStreamWriter(process.getOutputStream())));
     executorService.submit(runnable);

     ...

     executorService.shutdownNow();
 

Method Summary

Modifier and Type	Method and Description
boolean	cancel() Cancels the task.
static InputReaderTask	newDrainingTask(InputReader reader, InputProcessor processor) Creates the new task.
static InputReaderTask	newTask(InputReader reader, InputProcessor processor) Creates a new task.
void	run() Task repeatedly reads the data from the InputReader, passing the content to InputProcessor (if any).

Methods inherited from class java.lang.Object

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

Method Detail

newTask

@NonNull
public static InputReaderTask newTask(@NonNull
                                               InputReader reader,
                                               @NullAllowed
                                               InputProcessor processor)

Creates a new task. The task will read the data from reader processing them through processor (if any) until interrupted or canceled.

InputReader must be non blocking.

Parameters:

reader - data producer

processor - processor consuming the data, may be null

Returns:

task handling the read process

newDrainingTask

@NonNull
public static InputReaderTask newDrainingTask(@NonNull
                                                       InputReader reader,
                                                       @NullAllowed
                                                       InputProcessor processor)

Creates the new task. The task will read the data from reader processing them through processor (if any). When interrupted or canceled task will try to read all the remaining available data before exiting.

InputReader must be non blocking.

Parameters:

reader - data producer

processor - processor consuming the data, may be null

Returns:

task handling the read process

run

public void run()

Task repeatedly reads the data from the InputReader, passing the content to InputProcessor (if any).

It is not allowed to invoke run multiple times.

Specified by:

run in interface Runnable

cancel

public boolean cancel()

Cancels the task. If the task is not running or task is already canceled this is noop.

Specified by:

cancel in interface Cancellable

Returns:

true if the task was successfully canceled