Package de.aristaflow.adept2.util.objectpool

Class AbstractObjectWrapper<T,E extends Exception>

java.lang.Object

de.aristaflow.adept2.util.objectpool.AbstractObjectWrapper<T,E>

public abstract class AbstractObjectWrapper<T,E extends Exception>
extends Object

This is an abstract base class for wrapper implementations. It's only provided for convenience, i.e. object wrappers are not required to extend it.

See Also:

ObjectWrapperLifeCycle

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractObjectWrapper(ObjectPool<T,E> objectPool, T pooledObject)	Constructs a new AbstractObjectWrapper for the given object and pool.

Method Summary

Modifier and Type	Method	Description
protected void	_checkIn()	Checks the wrapped object back into the object pool.
protected void	_ensureIsValid()	Simply returns if the wrapper is still valid and throws an IllegalStateException if it isn't.
long	_getLastActiveTime()	Returns the last active time, i.e. the last time the wrapped object was used by the borrower.
protected T	_getObject()	Returns the wrapped object or throws an IllegalStateException if the wrapper has already been invalidated.
protected void	_invalidate()	Invalidates this wrapper, i.e. references to the wrapped object and the object pool are discarded.
protected boolean	_isValid()	Returns whether this wrapper is still valid.
protected void	_updateLastActiveTime()	Updates the last active time to the current system time.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractObjectWrapper

protected AbstractObjectWrapper(ObjectPool<T,E> objectPool,
                                T pooledObject)

Constructs a new AbstractObjectWrapper for the given object and pool.

Parameters:

objectPool - the object to be wrapped

pooledObject - the pool responsible for the given object

Method Detail

_getObject

protected T _getObject()
                throws E extends Exception

Returns the wrapped object or throws an IllegalStateException if the wrapper has already been invalidated.

This method is intended to be called in subclasses to implement the delegating methods. It will update the _getLastActiveTime() last active time} to the current system time and - as already mentioned - it will fail if the wrapper was invalidated.

In subclasses, this method will have to be overridden with a simple call to its super implementation in order to provide access to the implementation of ObjectWrapperLifeCycle.unwrap(Object).

Returns:

the wrapped object

Throws:

E - not thrown by this implementation, but may be thrown in sub classes if _ensureIsValid() is implemented differently

E extends Exception

_ensureIsValid

protected void _ensureIsValid()
                       throws E extends Exception

Simply returns if the wrapper is still valid and throws an IllegalStateException if it isn't. May be overridden in subclasses to either throw the same exception type with a different message or a domain-specific exception.

Throws:

IllegalStateException - if the wrapper has been invalidated (may change of overridden)

E - not thrown by this implementation, but may be thrown in sub classes

E extends Exception

_isValid

protected boolean _isValid()

Returns whether this wrapper is still valid. Invalidated wrappers will prevent all access to the wrapped object (at least by the burrower). Subsequent calls to _getObject() will raise an IllegalStateException.

Please note that this does in no way indicate whether the wrapped object is still valid!

Returns:

whether this wrapper is still valid

_invalidate

protected void _invalidate()

Invalidates this wrapper, i.e. references to the wrapped object and the object pool are discarded. After this method returns, calls to _getObject() will fail!

In subclasses, this method will have to be overridden with a simple call to its super implementation in order to provide access to the implementation of ObjectWrapperLifeCycle.invalidate(Object).

_checkIn

protected void _checkIn()
                 throws E extends Exception

Checks the wrapped object back into the object pool. The wrapper will be invalidated by the object pool in the process. The user of the object (through the wrapper) does not need to have a reference to the object pool in order to return it.

Throws:

E - passed through exception from ObjectPool.checkIn(Object)

E extends Exception

_getLastActiveTime

public long _getLastActiveTime()

Returns the last active time, i.e. the last time the wrapped object was used by the borrower. This time is automatically updated every time _getObject() is called.

This method may be overridden to fetch this information directly from the wrapped object.

Returns:

the last active time

_updateLastActiveTime

protected void _updateLastActiveTime()

Updates the last active time to the current system time. This method is implicitly called by _getObject().