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Spring Framework example source code file (CommonsPoolTargetSource.java)

This example Spring Framework source code file (CommonsPoolTargetSource.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Spring Framework tags/keywords

abstractpoolingtargetsource, beansexception, closing, commons, commonspooltargetsource, exception, exception, genericobjectpool, genericobjectpool, object, object, objectpool, objectpool, unsupportedoperationexception

The Spring Framework CommonsPoolTargetSource.java source code

/*
 * Copyright 2002-2007 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.aop.target;

import org.apache.commons.pool.ObjectPool;
import org.apache.commons.pool.PoolableObjectFactory;
import org.apache.commons.pool.impl.GenericObjectPool;

import org.springframework.beans.BeansException;
import org.springframework.core.Constants;

/**
 * TargetSource implementation that holds objects in a configurable
 * Jakarta Commons Pool.
 *
 * <p>By default, an instance of GenericObjectPool is created.
 * Subclasses may change the type of <code>ObjectPool used by
 * overriding the <code>createObjectPool() method.
 *
 * <p>Provides many configuration properties mirroring those of the Commons Pool
 * <code>GenericObjectPool class; these properties are passed to the
 * <code>GenericObjectPool during construction. If creating a subclass of this
 * class to change the <code>ObjectPool implementation type, pass in the values
 * of configuration properties that are relevant to your chosen implementation.
 *
 * <p>The testOnBorrow, testOnReturn and testWhileIdle
 * properties are explictly not mirrored because the implementation of
 * <code>PoolableObjectFactory used by this class does not implement
 * meaningful validation. All exposed Commons Pool properties use the corresponding
 * Commons Pool defaults: for example, 
 *
 * @author Rod Johnson
 * @author Rob Harrop
 * @author Juergen Hoeller
 * @see GenericObjectPool
 * @see #createObjectPool()
 * @see #setMaxSize
 * @see #setMaxIdle
 * @see #setMinIdle
 * @see #setMaxWait
 * @see #setTimeBetweenEvictionRunsMillis
 * @see #setMinEvictableIdleTimeMillis
 */
public class CommonsPoolTargetSource extends AbstractPoolingTargetSource
		implements PoolableObjectFactory {

	private static final Constants constants = new Constants(GenericObjectPool.class);


	private int maxIdle = GenericObjectPool.DEFAULT_MAX_IDLE;

	private int minIdle = GenericObjectPool.DEFAULT_MIN_IDLE;

	private long maxWait = GenericObjectPool.DEFAULT_MAX_WAIT;

	private long timeBetweenEvictionRunsMillis = GenericObjectPool.DEFAULT_TIME_BETWEEN_EVICTION_RUNS_MILLIS;

	private long minEvictableIdleTimeMillis = GenericObjectPool.DEFAULT_MIN_EVICTABLE_IDLE_TIME_MILLIS;

	private byte whenExhaustedAction = GenericObjectPool.DEFAULT_WHEN_EXHAUSTED_ACTION;

	/**
	 * The Jakarta Commons <code>ObjectPool used to pool target objects
	 */
	private ObjectPool pool;


	/**
	 * Create a CommonsPoolTargetSource with default settings.
	 * Default maximum size of the pool is 8.
	 * @see #setMaxSize
	 * @see GenericObjectPool#setMaxActive
	 */
	public CommonsPoolTargetSource() {
		setMaxSize(GenericObjectPool.DEFAULT_MAX_ACTIVE);
	}

	/**
	 * Set the maximum number of idle objects in the pool.
	 * Default is 8.
	 * @see GenericObjectPool#setMaxIdle
	 */
	public void setMaxIdle(int maxIdle) {
		this.maxIdle = maxIdle;
	}

	/**
	 * Return the maximum number of idle objects in the pool.
	 */
	public int getMaxIdle() {
		return this.maxIdle;
	}

	/**
	 * Set the minimum number of idle objects in the pool.
	 * Default is 0.
	 * @see GenericObjectPool#setMinIdle
	 */
	public void setMinIdle(int minIdle) {
		this.minIdle = minIdle;
	}

	/**
	 * Return the minimum number of idle objects in the pool.
	 */
	public int getMinIdle() {
		return this.minIdle;
	}

	/**
	 * Set the maximum waiting time for fetching an object from the pool.
	 * Default is -1, waiting forever.
	 * @see GenericObjectPool#setMaxWait
	 */
	public void setMaxWait(long maxWait) {
		this.maxWait = maxWait;
	}

	/**
	 * Return the maximum waiting time for fetching an object from the pool.
	 */
	public long getMaxWait() {
		return this.maxWait;
	}

	/**
	 * Set the time between eviction runs that check idle objects whether
	 * they have been idle for too long or have become invalid.
	 * Default is -1, not performing any eviction.
	 * @see GenericObjectPool#setTimeBetweenEvictionRunsMillis
	 */
	public void setTimeBetweenEvictionRunsMillis(long timeBetweenEvictionRunsMillis) {
		this.timeBetweenEvictionRunsMillis = timeBetweenEvictionRunsMillis;
	}

	/**
	 * Return the time between eviction runs that check idle objects.
	 */
	public long getTimeBetweenEvictionRunsMillis() {
		return this.timeBetweenEvictionRunsMillis;
	}

	/**
	 * Set the minimum time that an idle object can sit in the pool before
	 * it becomes subject to eviction. Default is 1800000 (30 minutes).
	 * <p>Note that eviction runs need to be performed to take this
	 * setting into effect.
	 * @see #setTimeBetweenEvictionRunsMillis
	 * @see GenericObjectPool#setMinEvictableIdleTimeMillis
	 */
	public void setMinEvictableIdleTimeMillis(long minEvictableIdleTimeMillis) {
		this.minEvictableIdleTimeMillis = minEvictableIdleTimeMillis;
	}

	/**
	 * Return the minimum time that an idle object can sit in the pool.
	 */
	public long getMinEvictableIdleTimeMillis() {
		return this.minEvictableIdleTimeMillis;
	}

	/**
	 * Set the action to take when the pool is exhausted. Uses the
	 * constant names defined in Commons Pool's GenericObjectPool class:
	 * "WHEN_EXHAUSTED_BLOCK", "WHEN_EXHAUSTED_FAIL", "WHEN_EXHAUSTED_GROW".
	 * @see #setWhenExhaustedAction(byte)
	 */
	public void setWhenExhaustedActionName(String whenExhaustedActionName) {
		setWhenExhaustedAction(constants.asNumber(whenExhaustedActionName).byteValue());
	}

	/**
	 * Set the action to take when the pool is exhausted. Uses the
	 * constant values defined in Commons Pool's GenericObjectPool class.
	 * @see GenericObjectPool#setWhenExhaustedAction(byte)
	 * @see GenericObjectPool#WHEN_EXHAUSTED_BLOCK
	 * @see GenericObjectPool#WHEN_EXHAUSTED_FAIL
	 * @see GenericObjectPool#WHEN_EXHAUSTED_GROW
	 */
	public void setWhenExhaustedAction(byte whenExhaustedAction) {
		this.whenExhaustedAction = whenExhaustedAction;
	}

	/**
	 * Return the action to take when the pool is exhausted.
	 */
	public byte getWhenExhaustedAction() {
		return whenExhaustedAction;
	}


	/**
	 * Creates and holds an ObjectPool instance.
	 * @see #createObjectPool()
	 */
	protected final void createPool() {
		logger.debug("Creating Commons object pool");
		this.pool = createObjectPool();
	}

	/**
	 * Subclasses can override this if they want to return a specific Commons pool.
	 * They should apply any configuration properties to the pool here.
	 * <p>Default is a GenericObjectPool instance with the given pool size.
	 * @return an empty Commons <code>ObjectPool.
	 * @see org.apache.commons.pool.impl.GenericObjectPool
	 * @see #setMaxSize
	 */
	protected ObjectPool createObjectPool() {
		GenericObjectPool gop = new GenericObjectPool(this);
		gop.setMaxActive(getMaxSize());
		gop.setMaxIdle(getMaxIdle());
		gop.setMinIdle(getMinIdle());
		gop.setMaxWait(getMaxWait());
		gop.setTimeBetweenEvictionRunsMillis(getTimeBetweenEvictionRunsMillis());
		gop.setMinEvictableIdleTimeMillis(getMinEvictableIdleTimeMillis());
		gop.setWhenExhaustedAction(getWhenExhaustedAction());
		return gop;
	}


	/**
	 * Borrow an object from the <code>ObjectPool.
	 */
	public Object getTarget() throws Exception {
		return this.pool.borrowObject();
	}

	/**
	 * Returns the specified object to the underlying <code>ObjectPool.
	 */
	public void releaseTarget(Object target) throws Exception {
		this.pool.returnObject(target);
	}

	public int getActiveCount() throws UnsupportedOperationException {
		return this.pool.getNumActive();
	}

	public int getIdleCount() throws UnsupportedOperationException {
		return this.pool.getNumIdle();
	}


	/**
	 * Closes the underlying <code>ObjectPool when destroying this object.
	 */
	public void destroy() throws Exception {
		logger.debug("Closing Commons ObjectPool");
		this.pool.close();
	}


	//----------------------------------------------------------------------------
	// Implementation of org.apache.commons.pool.PoolableObjectFactory interface
	//----------------------------------------------------------------------------

	public Object makeObject() throws BeansException {
		return newPrototypeInstance();
	}

	public void destroyObject(Object obj) throws Exception {
		destroyPrototypeInstance(obj);
	}

	public boolean validateObject(Object obj) {
		return true;
	}

	public void activateObject(Object obj) {
	}

	public void passivateObject(Object obj) {
	}

}

Other Spring Framework examples (source code examples)

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