记一个开源的操作Excel的类库
http://baike.baidu.com/link?url=O0MKFDKYJ6H7H_G-m9jJBvo96UBFFHb5IrgGuAX5P_xC3lheGjjfWqSKJNY5-98jHWKAUZJNtP-rFYp2W1hMBK
