android开发,将avoscloud-sdk-v3.1.2.jar放到libs目录,如下代码出错

import com.avos.avoscloud.AVOSCloud;
import com.avos.avoscloud.AVAnalytics;

提示:
Multiple markers at this line
- The import com.avos cannot be
resolved
- The import com.avos cannot be
resolved

我 clean了,重新build,等等,refresh了也没有用。