org.apache.avalon.excalibur.datasource

Class ResourceLimitingJdbcConnectionPool

java.lang.Object

org.apache.avalon.framework.logger.AbstractLogEnabled

org.apache.avalon.excalibur.pool.InstrumentedResourceLimitingPool

org.apache.avalon.excalibur.pool.TraceableResourceLimitingPool

org.apache.avalon.excalibur.pool.ValidatedResourceLimitingPool

org.apache.avalon.excalibur.datasource.ResourceLimitingJdbcConnectionPool

All Implemented Interfaces:

org.apache.avalon.excalibur.pool.Pool, org.apache.avalon.framework.activity.Disposable, org.apache.avalon.framework.logger.LogEnabled, org.apache.avalon.framework.thread.ThreadSafe, org.apache.excalibur.instrument.Instrumentable

public class ResourceLimitingJdbcConnectionPool
extends org.apache.avalon.excalibur.pool.ValidatedResourceLimitingPool

A ResourceLimiting JdbcConnectionPool which allows for fine configuration of how the pool scales to loads. The pool supports; weak and strong pool size limits, optional blocking gets when connections are not available, and automatic trimming of unused connections.

Since:

4.1

Version:

CVS $Revision: 1.4 $ $Date: 2004/02/28 11:47:14 $

Author:

Avalon Development Team

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.avalon.excalibur.pool.TraceableResourceLimitingPool

org.apache.avalon.excalibur.pool.TraceableResourceLimitingPool.State, org.apache.avalon.excalibur.pool.TraceableResourceLimitingPool.TraceException

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	m_autoCommit

Fields inherited from class org.apache.avalon.excalibur.pool.InstrumentedResourceLimitingPool

DEFAULT_INSTRUMENTABLE_NAME, INSTRUMENT_BLOCKS_NAME, INSTRUMENT_CREATES_NAME, INSTRUMENT_DECOMMISSIONS_NAME, INSTRUMENT_GETS_NAME, INSTRUMENT_PUTS_NAME, INSTRUMENT_READY_SIZE_NAME, INSTRUMENT_SIZE_NAME, m_semaphore

Fields inherited from interface org.apache.excalibur.instrument.Instrumentable

EMPTY_INSTRUMENT_ARRAY, EMPTY_INSTRUMENTABLE_ARRAY

Constructor Summary

Constructors

Constructor and Description
ResourceLimitingJdbcConnectionPool(org.apache.avalon.excalibur.pool.ObjectFactory factory, int max, boolean maxStrict, boolean blocking, long blockTimeout, long trimInterval, boolean autoCommit) Creates a new ResourceLimitingJdbcConnectionPool
ResourceLimitingJdbcConnectionPool(org.apache.avalon.excalibur.pool.ObjectFactory factory, int max, boolean maxStrict, boolean blocking, long blockTimeout, long trimInterval, boolean trace, boolean autoCommit) Creates a new ResourceLimitingJdbcConnectionPool

Method Summary

Methods

Modifier and Type	Method and Description
protected org.apache.avalon.excalibur.pool.Poolable	newPoolable() Create a new poolable instance by by calling the newInstance method on the pool's ObjectFactory.
protected boolean	validatePoolable(org.apache.avalon.excalibur.pool.Poolable poolable) Validates the poolable before it is provided to the caller of get on this pool.

Methods inherited from class org.apache.avalon.excalibur.pool.ValidatedResourceLimitingPool

get

Methods inherited from class org.apache.avalon.excalibur.pool.TraceableResourceLimitingPool

getState, put, removePoolable

Methods inherited from class org.apache.avalon.excalibur.pool.InstrumentedResourceLimitingPool

dispose, getChildInstrumentables, getInstrumentableName, getInstruments, getReadySize, getSize, permanentlyRemovePoolable, setInstrumentableName, trim

Methods inherited from class org.apache.avalon.framework.logger.AbstractLogEnabled

enableLogging, getLogger, setupLogger, setupLogger, setupLogger

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.avalon.framework.logger.LogEnabled

enableLogging

Field Detail

m_autoCommit

private boolean m_autoCommit

Constructor Detail

ResourceLimitingJdbcConnectionPool

public ResourceLimitingJdbcConnectionPool(org.apache.avalon.excalibur.pool.ObjectFactory factory,
                                  int max,
                                  boolean maxStrict,
                                  boolean blocking,
                                  long blockTimeout,
                                  long trimInterval,
                                  boolean trace,
                                  boolean autoCommit)

Creates a new ResourceLimitingJdbcConnectionPool

Parameters:

factory - The ObjectFactory which will be used to create new connections as needed by the pool.

max - Maximum number of connections which can be stored in the pool, 0 implies no limit.

maxStrict - true if the pool should never allow more than max connections to be created. Will cause an exception to be thrown if more than max connections are requested and blocking is false.

blocking - true if the pool should cause a thread calling get() to block when connections are not currently available in the pool.

blockTimeout - The maximum amount of time, in milliseconds, that a call to get() will block before an exception is thrown. A value of 0 implies an indefinate wait.

trimInterval - The minimum interval with which old unused connections will be removed from the pool. A value of 0 will cause the pool to never trim old connections.

trace - True if tracing of gets is enabled for the pool.

autoCommit - true if connections created by this pool should have autoCommit enabled.

ResourceLimitingJdbcConnectionPool

public ResourceLimitingJdbcConnectionPool(org.apache.avalon.excalibur.pool.ObjectFactory factory,
                                  int max,
                                  boolean maxStrict,
                                  boolean blocking,
                                  long blockTimeout,
                                  long trimInterval,
                                  boolean autoCommit)

Creates a new ResourceLimitingJdbcConnectionPool

Parameters:

factory - The ObjectFactory which will be used to create new connections as needed by the pool.

max - Maximum number of connections which can be stored in the pool, 0 implies no limit.

maxStrict - true if the pool should never allow more than max connections to be created. Will cause an exception to be thrown if more than max connections are requested and blocking is false.

blocking - true if the pool should cause a thread calling get() to block when connections are not currently available in the pool.

blockTimeout - The maximum amount of time, in milliseconds, that a call to get() will block before an exception is thrown. A value of 0 implies an indefinate wait.

trimInterval - The minimum interval with which old unused connections will be removed from the pool. A value of 0 will cause the pool to never trim old connections.

autoCommit - true if connections created by this pool should have autoCommit enabled.

Method Detail

newPoolable

protected org.apache.avalon.excalibur.pool.Poolable newPoolable()
                                                         throws java.lang.Exception

Create a new poolable instance by by calling the newInstance method on the pool's ObjectFactory. This is the method to override when you need to enforce creational policies. This method is only called by threads that have m_semaphore locked.

Overrides:

newPoolable in class org.apache.avalon.excalibur.pool.ValidatedResourceLimitingPool

Throws:

java.lang.Exception

validatePoolable

protected boolean validatePoolable(org.apache.avalon.excalibur.pool.Poolable poolable)

Validates the poolable before it is provided to the caller of get on this pool. This implementation of the validation method always returns true indicating that the Poolable is valid. The pool is not locked by the current thread when this method is called.

Overrides:

validatePoolable in class org.apache.avalon.excalibur.pool.ValidatedResourceLimitingPool

Parameters:

poolable - The Poolable to be validated

Returns:

true if the Poolable is valid, false if it should be removed from the pool.