EHCAche源码分析：
首先看缓存类CacheManager
public class CacheManager {
//该类在默认情况下读取CLASSPATH下的ehcache.xml文件，并且是单例模式创建新的缓存类
/**
* Keeps track of all known CacheManagers. Used to check on conflicts.
* CacheManagers should remove themselves from this list during shut down.
*/
public static final List ALL_CACHE_MANAGERS = Collections.synchronizedList(new ArrayList());
private static final Log LOG = LogFactory.getLog(CacheManager.class.getName());
/**
* The Singleton Instance.
*/
private static CacheManager singleton;
/**
* Caches managed by this manager.
*/
protected final Map caches = new HashMap();
/**
* Default cache cache.
*/
private Ehcache defaultCache;
调用该类需要CacheManager manager = new VacheManager();
新建一个就要：manager.create();
public static CacheManager create() throws CacheException {
synchronized (CacheManager.class) {
if (singleton == null) {
if (LOG.isDebugEnabled()) {
LOG.debug("Creating new CacheManager with default config");
}
singleton = new CacheManager();
} else {
if (LOG.isDebugEnabled()) {
LOG.debug("Attempting to create an existing singleton. Existing singleton returned.");
}
}
return singleton;
}
}
该方法通过默认配置，以工厂方法创建一个单例对象缓存管理器
也可以通过getInstance()来获取实例
public static CacheManager getInstance() throws CacheException {
return CacheManager.create();
}
根据缓存名称获取缓存对象
public synchronized Cache getCache(String name) throws IllegalStateException, ClassCastException {
checkStatus();
return (Cache) caches.get(name);
}
缓存是以Map集合存储数据的，也可以通过
public synchronized Ehcache getEhcache(String name) throws IllegalStateException {
checkStatus();
return (Ehcache) caches.get(name);
}
来获取EHcache
那缓存是如何存储的呢，看以下代码就知道了
public synchronized void addCache(String cacheName) throws IllegalStateException,
ObjectExistsException, CacheException {
checkStatus();
//NPE guard
if (cacheName == null || cacheName.length() == 0) {
return;
}
if (caches.get(cacheName) != null) {
throw new ObjectExistsException("Cache " + cacheName + " already exists");
}
Ehcache cache = null;
try {
cache = (Ehcache) defaultCache.clone();
} catch (CloneNotSupportedException e) {
LOG.error("Failure adding cache. Initial cause was " + e.getMessage(), e);
}
if (cache != null) {
cache.setName(cacheName);
}
addCache(cache);
}
通过addCache()方法，判断cacheName是否已经存在，如果不存在，那就在默认缓存中克隆clone()到cache里面，也就是map里面。如果存在就不做处理
以上是我对EHCache的一点理解，以后还会继续补充
原文：http://www.cnblogs.com/wcyBlog/p/3937572.html