/*
* Copyright 2002-2012 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.concurrent;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import org.springframework.cache.Cache;
import org.springframework.cache.CacheManager;
/**
* {@link CacheManager} implementation that lazily builds {@link ConcurrentMapCache}
* instances for each {@link #getCache} request. Also supports a 'static' mode where
* the set of cache names is pre-defined through {@link #setCacheNames}, with no
* dynamic creation of further cache regions at runtime.
*
* @author Juergen Hoeller
* @since 3.1
*/
public class ConcurrentMapCacheManager implements CacheManager {
private final ConcurrentMap<String, Cache> cacheMap = new ConcurrentHashMap<String, Cache>(16);
private boolean dynamic = true;
/**
* Construct a dynamic ConcurrentMapCacheManager,
* lazily creating cache instances as they are being requested.
*/
public ConcurrentMapCacheManager() {
}
/**
* Construct a static ConcurrentMapCacheManager,
* managing caches for the specified cache names only.
*/
public ConcurrentMapCacheManager(String... cacheNames) {
setCacheNames(Arrays.asList(cacheNames));
}
/**
* Specify the set of cache names for this CacheManager's 'static' mode.
* <p>The number of caches and their names will be fixed after a call to this method,
* with no creation of further cache regions at runtime.
*/
public void setCacheNames(Collection<String> cacheNames) {
if (cacheNames != null) {
for (String name : cacheNames) {
this.cacheMap.put(name, createConcurrentMapCache(name));
}
this.dynamic = false;
}
}
public Collection<String> getCacheNames() {
return Collections.unmodifiableSet(this.cacheMap.keySet());
}
public Cache getCache(String name) {
Cache cache = this.cacheMap.get(name);
if (cache == null && this.dynamic) {
synchronized (this.cacheMap) {
cache = this.cacheMap.get(name);
if (cache == null) {
cache = createConcurrentMapCache(name);
this.cacheMap.put(name, cache);
}
}
}
return cache;
}
/**
* Create a new ConcurrentMapCache instance for the specified cache name.
* @param name the name of the cache
* @return the ConcurrentMapCache (or a decorator thereof)
*/
protected Cache createConcurrentMapCache(String name) {
return new ConcurrentMapCache(name);
}
}