public WhereSql buildWhereSql(JvmDataReq req) {
        return new WhereSql()
                .andOnNotEmpty("identity = ?", req.getIdentity())
                .andBetween("timestamp", req.getStartTime(), req.getEndTime());

    }
@author Robert HG (254963746@qq.com) on 3/9/16.
lts-admin/src/main/java/com/github/ltsopensource/admin/access/mysql/MysqlBackendJVMMemoryAccess.java