net.sf.ehcache.CacheException: Another unnamedCacheManager already exists in the same VM

今天在项目中配置多SessionFactory，抛错

Caused by: net.sf.ehcache.CacheException: Another unnamedCacheManager already exists in the same VM. Please provide uniquenames for each CacheManager in the config or do one offollowing:

1. Use one of the CacheManager.create() static factory methodsto reuse same CacheManager with same name or create one ifnecessary

2. Shutdown the earlier cacheManager before creating new onewith same name.

经查，ehcache在2.5以后，CacheManager使用了Singleton，这样在创建多个CacheManager时就会产生上述错误。

http://ehcache.org/documentation/get-started/concepts 是官方解释

解决方法是在Hibernate的hibernateProperties配置中，加上

<propkey="hibernate.cache.region.factory_class">

   org.hibernate.cache.SingletonEhCacheRegionFactory

</prop>

原文：http://blog.sina.com.cn/s/blog_6e0810c701014dmv.html