org.apache.commons.pool
Class BaseObjectPool

java.lang.Object
  extended by org.apache.commons.pool.BaseObjectPool
All Implemented Interfaces:
ObjectPool
Direct Known Subclasses:
GenericObjectPool, SoftReferenceObjectPool, StackObjectPool

public abstract class BaseObjectPool
extends Object
implements ObjectPool

A simple base implementation of ObjectPool. Optional operations are implemented to either do nothing, return a value indicating it is unsupported or throw UnsupportedOperationException.

Since:
Pool 1.0
Version:
$Revision: 791364 $ $Date: 2009-07-05 21:52:27 -0400 (Sun, 05 Jul 2009) $
Author:
Rodney Waldhoff, Sandy McArthur

Constructor Summary
BaseObjectPool()
           
 
Method Summary
 void addObject()
          Not supported in this base implementation.
protected  void assertOpen()
          Throws an IllegalStateException when this pool has been closed.
abstract  Object borrowObject()
          Obtains an instance from the pool.
 void clear()
          Not supported in this base implementation.
 void close()
          Close this pool.
 int getNumActive()
          Not supported in this base implementation.
 int getNumIdle()
          Not supported in this base implementation.
abstract  void invalidateObject(Object obj)
          Invalidates an object from the pool.
protected  boolean isClosed()
          Has this pool instance been closed.
abstract  void returnObject(Object obj)
          Returns an instance to the pool.
 void setFactory(PoolableObjectFactory factory)
          Not supported in this base implementation.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

BaseObjectPool

public BaseObjectPool()
Method Detail

borrowObject

public abstract Object borrowObject()
                             throws Exception
Obtains an instance from the pool.

Specified by:
borrowObject in interface ObjectPool
Returns:
an instance from the pool
Throws:
Exception - if an instance cannot be obtained from the pool

returnObject

public abstract void returnObject(Object obj)
                           throws Exception
Returns an instance to the pool.

Specified by:
returnObject in interface ObjectPool
Parameters:
obj - instance to return to the pool
Throws:
Exception

invalidateObject

public abstract void invalidateObject(Object obj)
                               throws Exception
Invalidates an object from the pool. By contract, obj must have been obtained using borrowObject or a related method as defined in an implementation or sub-interface.

This method should be used when an object that has been borrowed is determined (due to an exception or other problem) to be invalid.

Specified by:
invalidateObject in interface ObjectPool
Parameters:
obj - a borrowed instance to be disposed.
Throws:
Exception

getNumIdle

public int getNumIdle()
               throws UnsupportedOperationException
Not supported in this base implementation.

Specified by:
getNumIdle in interface ObjectPool
Returns:
a negative value.
Throws:
UnsupportedOperationException

getNumActive

public int getNumActive()
                 throws UnsupportedOperationException
Not supported in this base implementation.

Specified by:
getNumActive in interface ObjectPool
Returns:
a negative value.
Throws:
UnsupportedOperationException

clear

public void clear()
           throws Exception,
                  UnsupportedOperationException
Not supported in this base implementation.

Specified by:
clear in interface ObjectPool
Throws:
UnsupportedOperationException
Exception

addObject

public void addObject()
               throws Exception,
                      UnsupportedOperationException
Not supported in this base implementation. Always throws an UnsupportedOperationException, subclasses should override this behavior.

Specified by:
addObject in interface ObjectPool
Throws:
UnsupportedOperationException
Exception - when PoolableObjectFactory.makeObject() fails.
IllegalStateException - after ObjectPool.close() has been called on this pool.

close

public void close()
           throws Exception
Close this pool. This affects the behavior of isClosed and assertOpen.

Specified by:
close in interface ObjectPool
Throws:
Exception - deprecated: implementations should silently fail if not all resources can be freed.

setFactory

public void setFactory(PoolableObjectFactory factory)
                throws IllegalStateException,
                       UnsupportedOperationException
Not supported in this base implementation. Always throws an UnsupportedOperationException, subclasses should override this behavior.

Specified by:
setFactory in interface ObjectPool
Parameters:
factory - the PoolableObjectFactory
Throws:
UnsupportedOperationException
IllegalStateException

isClosed

protected final boolean isClosed()
Has this pool instance been closed.

Returns:
true when this pool has been closed.

assertOpen

protected final void assertOpen()
                         throws IllegalStateException
Throws an IllegalStateException when this pool has been closed.

Throws:
IllegalStateException - when this pool has been closed.
See Also:
isClosed()


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