org.microbean.cdi

Class AbstractBlockingExtension

java.lang.Object

org.microbean.cdi.AbstractBlockingExtension

All Implemented Interfaces:

Extension

public abstract class AbstractBlockingExtension
extends Object
implements Extension

An abstract Extension whose implementations can legally and politely prevent a CDI container from exiting.

The most common use case for such an implementation is an Extension that wishes to launch a server of some kind and to notionally block until someone interrupts the process.

Author:

Laird Nelson

See Also:

CountDownLatch, CountDownLatch.countDown(), CountDownLatch.await()

Field Summary

Fields

Modifier and Type	Field and Description
protected Logger	logger The Logger used by instances of this class.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractBlockingExtension() Creates a new AbstractBlockingExtension by calling the appropriate constructor with a new CountDownLatch with an initial count of 1.
protected	AbstractBlockingExtension(CountDownLatch latch) Creates a new AbstractBlockingExtension that uses the supplied CountDownLatch for governing blocking behavior, and installs a shutdown hook that (indirectly) calls countDown() on the supplied latch.

Method Summary

Modifier and Type	Method and Description
protected Logger	createLogger() Returns a Logger suitable for use with this AbstractBlockingExtension implementation.
void	unblock() Calls CountDownLatch.countDown() on the CountDownLatch supplied at construction time.
static void	unblockAll() Unblocks all known instances of the AbstractBlockingExtension class by calling their associated CountDownLatches supplied at their construction time.

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected final Logger logger

The Logger used by instances of this class.

This field is never null.

See Also:

createLogger()

Constructor Detail

AbstractBlockingExtension

protected AbstractBlockingExtension()

Creates a new AbstractBlockingExtension by calling the appropriate constructor with a new CountDownLatch with an initial count of 1.

See Also:

AbstractBlockingExtension(CountDownLatch)

AbstractBlockingExtension

protected AbstractBlockingExtension(CountDownLatch latch)

Creates a new AbstractBlockingExtension that uses the supplied CountDownLatch for governing blocking behavior, and installs a shutdown hook that (indirectly) calls countDown() on the supplied latch.

Parameters:

latch - a CountDownLatch whose CountDownLatch.countDown() and CountDownLatch.await() methods will be used to control blocking behavior; may be null in which case no blocking behavior will take place

Method Detail

createLogger

protected Logger createLogger()

Returns a Logger suitable for use with this AbstractBlockingExtension implementation.

This method never returns null.

Overrides of this method must not return null.

Returns:

a non-null Logger

unblock

public void unblock()

Calls CountDownLatch.countDown() on the CountDownLatch supplied at construction time.

This method may be invoked more than once without any side effects.

See Also:

unblockAll()

unblockAll

public static final void unblockAll()

Unblocks all known instances of the AbstractBlockingExtension class by calling their associated CountDownLatches supplied at their construction time.

This method may be invoked more than once without any side effects.

See Also:

unblock()