com.sun.grizzly.util
Class StateHolder<E>

java.lang.Object
  com.sun.grizzly.util.StateHolder<E>

public class StateHolder<E>
extends Object

Class, which holds the state. Provides API for state change notification, state read/write access locking.

Author:

Alexey Stashok

Nested Class Summary

static class	StateHolder.ConditionListener<E> Common ConditionListener class, which could be used with StateHolder, to register custom conditions.
static class	StateHolder.EqualConditionListener<E> Equal ConditionListener implementation
static class	StateHolder.EventListener EventListener class, which is a part of EventConditionListener, and implements notificatation logic, when condition becomes true.
static class	StateHolder.NotEqualConditionListener<E> Not equal ConditionListener implementation

Constructor Summary

StateHolder()
Constructs StateHolder.

StateHolder(boolean isLockEnabled)
Constructs StateHolder.

Method Summary

protected void	checkConditionListeners(E state)
E	getState() Gets current state Current StateHolder locking mode will be used
E	getState(boolean locked) Gets current state
ReentrantReadWriteLock	getStateLocker() Gets Read/Write locker, which is used by this StateHolder
boolean	isLockEnabled() Gets current locking mode
void	notifyWhenConditionMatchState(StateHolder.ConditionListener<E> conditionListener) Register custom condition listener, which will be notified, when listener's condition will become true.
StateHolder.ConditionListener<E>	notifyWhenStateIsEqual(E state, Object listener) Register listener, which will be notified, when state will be equal to passed one.
StateHolder.ConditionListener<E>	notifyWhenStateIsNotEqual(E state, Object listener) Register listener, which will be notified, when state will become not equal to passed one.
void	removeConditionListener(StateHolder.ConditionListener<E> conditionListener)
void	setLockEnabled(boolean isLockEnabled) Setss current locking mode
void	setState(E state) Sets current state Current StateHolder locking mode will be used
void	setState(E state, boolean locked) Sets current state

Methods inherited from class java.lang.Object

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

Constructor Detail

StateHolder

public StateHolder()

Constructs StateHolder. StateHolder will work in not-locking mode.

StateHolder

public StateHolder(boolean isLockEnabled)

Constructs StateHolder.

Parameters:

isLockEnabled - locking mode

Method Detail

getState

public E getState()

Gets current state Current StateHolder locking mode will be used

Returns:

state

getState

public E getState(boolean locked)

Gets current state

Parameters:

locked - if true, get will be invoked in locking mode, false - non-locked

Returns:

state

setState

public void setState(E state)

Sets current state Current StateHolder locking mode will be used

Parameters:

state -

setState

public void setState(E state,
                     boolean locked)

Sets current state

Parameters:

state -

locked - if true, set will be invoked in locking mode, false - non-locking

getStateLocker

public ReentrantReadWriteLock getStateLocker()

Gets Read/Write locker, which is used by this StateHolder

Returns:

locker

isLockEnabled

public boolean isLockEnabled()

Gets current locking mode

Returns:

true, if mode is set to locking, false otherwise

setLockEnabled

public void setLockEnabled(boolean isLockEnabled)

Setss current locking mode

Parameters:

isLockEnabled - true, if mode will be set to locking, false otherwise

notifyWhenStateIsEqual

public StateHolder.ConditionListener<E> notifyWhenStateIsEqual(E state,
                                                               Object listener)

Register listener, which will be notified, when state will be equal to passed one. Once listener will be notified - it will be removed from this StateHolder's listener set.

Parameters:

state - State, listener is interested in

listener - Object, which will be notified. This StateHolder implementation works with Runnable, Callable, CountDownLatch, Object listeners

Returns:

ConditionListener, if current state is not equal to required and listener was registered, null if current state is equal to required. In both cases listener will be notified

notifyWhenStateIsNotEqual

public StateHolder.ConditionListener<E> notifyWhenStateIsNotEqual(E state,
                                                                  Object listener)

Register listener, which will be notified, when state will become not equal to passed one. Once listener will be notified - it will be removed from this StateHolder's listener set.

Parameters:

state - State, listener is interested in

listener - Object, which will be notified. This StateHolder implementation works with Runnable, Callable, CountDownLatch, Object listeners

Returns:

ConditionListener, if current state is equal to required and listener was registered, null if current state is not equal to required. In both cases listener will be notified

notifyWhenConditionMatchState

public void notifyWhenConditionMatchState(StateHolder.ConditionListener<E> conditionListener)

Register custom condition listener, which will be notified, when listener's condition will become true. Once listener will be notified - it will be removed from this StateHolder's listener set.

Parameters:

conditionListener - contains both condition and listener, which will be called, when condition become true

removeConditionListener

public void removeConditionListener(StateHolder.ConditionListener<E> conditionListener)

checkConditionListeners

protected void checkConditionListeners(E state)