Java缓存框架 EhCache EhCache 是一个纯Java的进程内缓存框架，具有快速、精干等特点，是Hibernate中默认的CacheProvider。
主要的特性有：
1. 快速.
2. 简单.
3. 多种缓存策略
4. 缓存数据有两级：内存和磁盘，因此无需担心容量问题
5. 缓存数据会在虚拟机重启的过程中写入磁盘
6. 可以通过RMI、可插入API等方式进行分布式缓存
7. 具有缓存和缓存管理器的侦听接口
8. 支持多缓存管理器实例，以及一个实例的多个缓存区域
9. 提供Hibernate的缓存实现
Ehcache Core 2.4.1发行说明如下：
Updates and Enhancements
·Created improved toString method on ResultImpl
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Please refer to Terracotta 3.5.0 920.html">Release notes for more detailed information on new features Ehcache 2.4.0 and up.
Fix list in Jira
Ehcache 2.4.1 EHC Jira Project
Other Resolved Issues
·5396 - NullPointerException using Hibernate if you don't specify that NonStopCache is disabled
·5376 - The ehcache xa transactional mode (not xa_strict, that one is fine) doesn't play 100% well with the Atomikos transaction manager: if all other XA resources participating in the transaction return XA_RDONLY during prepare then Atomikos will mistakenly report the transaction's status as UNKNOWN instead of COMMITTED, making ehcache rollback the changes.
Known Issues
·EHC-837 putIfAbsent does not work as intended with synchronous RMI distributed caches. None of the CAS operations guarantee this for replicated caching, only for standalone and Terracotta Server Array distributed caches.
·JRockit Issues with versions below r28.
·Workaround: At least version r28 of JRockit must be used when using BigMemory
·For Distributed Ehcache, the first release does not support BigMemory on client nodes (L1s), but rather only on Terracotta Server Array (L2s).
·On Firefox and Chrome the Ehcache Monitor charts may go blank. http://www.sencha.com/forum/showthread.php?78788-OPEN-197-3.0.0-svn-5208-this.swf.setDataprovider-is-not-a-function
Workaround: refresh browser
·We recommend using a 64bit JVM when using BigMemory. With 32bit JVMs the total addressable memory (on-heap and off-heap is limited by the 32bit address space AND some JVM version specific limits that vary depending on the operating system they are running on). For Example with 32bit JRockit, the max addressable memory is about 3.6GB, permitting up to 2.8GB off-heap and 800MB on-heap. For 32bit Hotspot the max off-heap size is typically <2GB. Some experimentation may be required.
下载地址：http://sourceforge.net/projects/ehcache/files/ehcache/ehcache-2.4.1/ehcache-2.4.1-distribution.tar.gz/download