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Spring Framework example source code file (EhCacheFactoryBean.java)

This example Spring Framework source code file (EhCacheFactoryBean.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

blockingcache, cache, cache, cachemanager, cachemanager, ehcache, ehcache, initializingbean, io, ioexception, selfpopulatingcache, string, string, updatingcacheentryfactory, using

The Spring Framework EhCacheFactoryBean.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.cache.ehcache;

import java.io.IOException;

import net.sf.ehcache.Cache;
import net.sf.ehcache.CacheException;
import net.sf.ehcache.CacheManager;
import net.sf.ehcache.Ehcache;
import net.sf.ehcache.constructs.blocking.BlockingCache;
import net.sf.ehcache.constructs.blocking.CacheEntryFactory;
import net.sf.ehcache.constructs.blocking.SelfPopulatingCache;
import net.sf.ehcache.constructs.blocking.UpdatingCacheEntryFactory;
import net.sf.ehcache.constructs.blocking.UpdatingSelfPopulatingCache;
import net.sf.ehcache.store.MemoryStoreEvictionPolicy;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.beans.factory.BeanNameAware;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.util.Assert;

/**
 * FactoryBean that creates a named EHCache {@link net.sf.ehcache.Cache} instance
 * (or a decorator that implements the {@link net.sf.ehcache.Ehcache} interface),
 * representing a cache region within an EHCache {@link net.sf.ehcache.CacheManager}.
 *
 * <p>If the specified named cache is not configured in the cache configuration descriptor,
 * this FactoryBean will construct an instance of a Cache with the provided name and the
 * specified cache properties and add it to the CacheManager for later retrieval. If some
 * or all properties are not set at configuration time, this FactoryBean will use defaults.
 *
 * <p>Note: If the named Cache instance is found, the properties will be ignored and the
 * Cache instance will be retrieved from the CacheManager.
 *
 * <p>Note: As of Spring 2.0, this FactoryBean is based on EHCache 1.2's API (in particular
 * the Ehcache interface and the extended Cache constructor). It is not compatible with
 * EHCache 1.1 anymore; please upgrade to EHCache 1.2.4 or higher.
 *
 * @author Dmitriy Kopylenko
 * @author Juergen Hoeller
 * @since 1.1.1
 * @see #setCacheManager
 * @see EhCacheManagerFactoryBean
 * @see net.sf.ehcache.Cache
 */
public class EhCacheFactoryBean implements FactoryBean, BeanNameAware, InitializingBean {

	protected final Log logger = LogFactory.getLog(getClass());

	private CacheManager cacheManager;

	private String cacheName;

	private int maxElementsInMemory = 10000;

	private int maxElementsOnDisk = 10000000;

	private MemoryStoreEvictionPolicy memoryStoreEvictionPolicy = MemoryStoreEvictionPolicy.LRU;

	private boolean overflowToDisk = true;

	private String diskStorePath;

	private boolean eternal = false;

	private int timeToLive = 120;

	private int timeToIdle = 120;

	private boolean diskPersistent = false;

	private int diskExpiryThreadIntervalSeconds = 120;

	private boolean blocking = false;

	private CacheEntryFactory cacheEntryFactory;

	private String beanName;

	private Ehcache cache;


	/**
	 * Set a CacheManager from which to retrieve a named Cache instance.
	 * By default, <code>CacheManager.getInstance() will be called.
	 * <p>Note that in particular for persistent caches, it is advisable to
	 * properly handle the shutdown of the CacheManager: Set up a separate
	 * EhCacheManagerFactoryBean and pass a reference to this bean property.
	 * <p>A separate EhCacheManagerFactoryBean is also necessary for loading
	 * EHCache configuration from a non-default config location.
	 * @see EhCacheManagerFactoryBean
	 * @see net.sf.ehcache.CacheManager#getInstance
	 */
	public void setCacheManager(CacheManager cacheManager) {
		this.cacheManager = cacheManager;
	}

	/**
	 * Set a name for which to retrieve or create a cache instance.
	 * Default is the bean name of this EhCacheFactoryBean.
	 */
	public void setCacheName(String cacheName) {
		this.cacheName = cacheName;
	}

	/**
	 * Specify the maximum number of cached objects in memory.
	 * Default is 10000 elements.
	 */
	public void setMaxElementsInMemory(int maxElementsInMemory) {
		this.maxElementsInMemory = maxElementsInMemory;
	}

	/**
	 * Specify the maximum number of cached objects on disk.
	 * Default is 10000000 elements.
	 */
	public void setMaxElementsOnDisk(int maxElementsOnDisk) {
		this.maxElementsOnDisk = maxElementsOnDisk;
	}

	/**
	 * Set the memory style eviction policy for this cache.
	 * Supported values are "LRU", "LFU" and "FIFO", according to the
	 * constants defined in EHCache's MemoryStoreEvictionPolicy class.
	 * Default is "LRU".
	 */
	public void setMemoryStoreEvictionPolicy(MemoryStoreEvictionPolicy memoryStoreEvictionPolicy) {
		Assert.notNull(memoryStoreEvictionPolicy, "memoryStoreEvictionPolicy must not be null");
		this.memoryStoreEvictionPolicy = memoryStoreEvictionPolicy;
	}

	/**
	 * Set whether elements can overflow to disk when the in-memory cache
	 * has reached the maximum size limit. Default is "true".
	 */
	public void setOverflowToDisk(boolean overflowToDisk) {
		this.overflowToDisk = overflowToDisk;
	}

	/**
	 * Set the location of temporary files for the disk store of this cache.
	 * Default is the CacheManager's disk store path.
	 */
	public void setDiskStorePath(String diskStorePath) {
		this.diskStorePath = diskStorePath;
	}

	/**
	 * Set whether elements are considered as eternal. If "true", timeouts
	 * are ignored and the element is never expired. Default is "false".
	 */
	public void setEternal(boolean eternal) {
		this.eternal = eternal;
	}

	/**
	 * Set t he time in seconds to live for an element before it expires,
	 * i.e. the maximum time between creation time and when an element expires.
	 * It is only used if the element is not eternal. Default is 120 seconds.
	 */
	public void setTimeToLive(int timeToLive) {
		this.timeToLive = timeToLive;
	}

	/**
	 * Set the time in seconds to idle for an element before it expires, that is,
	 * the maximum amount of time between accesses before an element expires.
	 * This is only used if the element is not eternal. Default is 120 seconds.
	 */
	public void setTimeToIdle(int timeToIdle) {
		this.timeToIdle = timeToIdle;
	}

	/**
	 * Set whether the disk store persists between restarts of the Virtual Machine.
	 * The default is "false".
	 */
	public void setDiskPersistent(boolean diskPersistent) {
		this.diskPersistent = diskPersistent;
	}

	/**
	 * Set the number of seconds between runs of the disk expiry thread.
	 * The default is 120 seconds.
	 */
	public void setDiskExpiryThreadIntervalSeconds(int diskExpiryThreadIntervalSeconds) {
		this.diskExpiryThreadIntervalSeconds = diskExpiryThreadIntervalSeconds;
	}

	/**
	 * Set whether to use a blocking cache that lets read attempts block
	 * until the requested element is created.
	 * <p>If you intend to build a self-populating blocking cache,
	 * consider specifying a {@link #setCacheEntryFactory CacheEntryFactory}.
	 * @see net.sf.ehcache.constructs.blocking.BlockingCache
	 * @see #setCacheEntryFactory
	 */
	public void setBlocking(boolean blocking) {
		this.blocking = blocking;
	}

	/**
	 * Set an EHCache {@link net.sf.ehcache.constructs.blocking.CacheEntryFactory}
	 * to use for a self-populating cache. If such a factory is specified,
	 * the cache will be decorated with EHCache's
	 * {@link net.sf.ehcache.constructs.blocking.SelfPopulatingCache}.
	 * <p>The specified factory can be of type
	 * {@link net.sf.ehcache.constructs.blocking.UpdatingCacheEntryFactory},
	 * which will lead to the use of an
	 * {@link net.sf.ehcache.constructs.blocking.UpdatingSelfPopulatingCache}.
	 * <p>Note: Any such self-populating cache is automatically a blocking cache.
	 * @see net.sf.ehcache.constructs.blocking.SelfPopulatingCache
	 * @see net.sf.ehcache.constructs.blocking.UpdatingSelfPopulatingCache
	 * @see net.sf.ehcache.constructs.blocking.UpdatingCacheEntryFactory
	 */
	public void setCacheEntryFactory(CacheEntryFactory cacheEntryFactory) {
		this.cacheEntryFactory = cacheEntryFactory;
	}

	public void setBeanName(String name) {
		this.beanName = name;
	}


	public void afterPropertiesSet() throws CacheException, IOException {
		// If no CacheManager given, fetch the default.
		if (this.cacheManager == null) {
			if (logger.isDebugEnabled()) {
				logger.debug("Using default EHCache CacheManager for cache region '" + this.cacheName + "'");
			}
			this.cacheManager = CacheManager.getInstance();
		}

		// If no cache name given, use bean name as cache name.
		if (this.cacheName == null) {
			this.cacheName = this.beanName;
		}

		// Fetch cache region: If none with the given name exists,
		// create one on the fly.
		Cache rawCache = null;
		if (this.cacheManager.cacheExists(this.cacheName)) {
			if (logger.isDebugEnabled()) {
				logger.debug("Using existing EHCache cache region '" + this.cacheName + "'");
			}
			rawCache = this.cacheManager.getCache(this.cacheName);
		}
		else {
			if (logger.isDebugEnabled()) {
				logger.debug("Creating new EHCache cache region '" + this.cacheName + "'");
			}
			rawCache = createCache();
			this.cacheManager.addCache(rawCache);
		}

		// Decorate cache if necessary.
		Ehcache decoratedCache = decorateCache(rawCache);
		if (decoratedCache != rawCache) {
			this.cacheManager.replaceCacheWithDecoratedCache(rawCache, decoratedCache);
		}
		this.cache = decoratedCache;
	}

	/**
	 * Create a raw Cache object based on the configuration of this FactoryBean.
	 */
	private Cache createCache() {
		return new Cache(
				this.cacheName, this.maxElementsInMemory, this.memoryStoreEvictionPolicy,
				this.overflowToDisk, this.diskStorePath, this.eternal, this.timeToLive, this.timeToIdle,
				this.diskPersistent, this.diskExpiryThreadIntervalSeconds, null, null, this.maxElementsOnDisk);
	}

	/**
	 * Decorate the given Cache, if necessary.
	 * <p>The default implementation simply returns the given cache object as-is.
	 * @param cache the raw Cache object, based on the configuration of this FactoryBean
	 * @return the (potentially decorated) cache object to be registered with the CacheManager
	 */
	protected Ehcache decorateCache(Cache cache) {
		if (this.cacheEntryFactory != null) {
			if (this.cacheEntryFactory instanceof UpdatingCacheEntryFactory) {
				return new UpdatingSelfPopulatingCache(cache, (UpdatingCacheEntryFactory) this.cacheEntryFactory);
			}
			else {
				return new SelfPopulatingCache(cache, this.cacheEntryFactory);
			}
		}
		if (this.blocking) {
			return new BlockingCache(cache);
		}
		return cache;
	}


	public Object getObject() {
		return this.cache;
	}

	public Class getObjectType() {
		return (this.cache != null ? this.cache.getClass() : Ehcache.class);
	}

	public boolean isSingleton() {
		return true;
	}

}

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