注意：分布式配置依赖于ehcache-1.3.0.jar、backport-util-concurrent.jar包，ehcache必须是1.3以上。

配置ehcache作为分布式缓存，需要修改ehcache.xml，增加下面的内容:

<cacheManagerPeerProviderFactory
            class="net.sf.ehcache.distribution.RMICacheManagerPeerProviderFactory"
            properties="peerDiscovery=automatic,
                        multicastGroupAddress=230.0.0.1,
                        multicastGroupPort=4446"/>


<cacheManagerPeerListenerFactory
class="net.sf.ehcache.distribution.RMICacheManagerPeerListenerFactory"/>

and then at least one cache declaration with

<cacheEventListenerFactory
    class="net.sf.ehcache.distribution.RMICacheReplicatorFactory"/>

in it. An example cache is:

    <cache name="sampleDistributedCache1"
           maxElementsInMemory="10"
           eternal="false"
           timeToIdleSeconds="100"
           timeToLiveSeconds="100"
           overflowToDisk="false">
        <cacheEventListenerFactory
            class="net.sf.ehcache.distribution.RMICacheReplicatorFactory"/>
    </cache>

Each server in the cluster can have the same config.

Ehcache API的用法：

  Set set=new HashSet();
  set.add("广州");
  set.add("香港");

  net.sf.ehcache.CacheManager manager = new net.sf.ehcache.CacheManager();
  Cache cache = manager.getCache("a");
  Element element = new Element("key1", set);
  cache.put(element);  
  
  Element element2 = cache.get("key1");
  Serializable value = element2.getValue();
  System.out.println("value:"+value);