private void initMongo() {
		if (initialized) {
			if (mongo == null) {// init mongo error
				throw new DataAccessException("创建mongo实例失败");
			}
		} else {
			try {
				mongo = new Mongo(host, port);
			} catch (UnknownHostException e) {
				LOGGER.error("创建mongo实例失败：", e);
			} catch (MongoException e) {
				LOGGER.error("创建mongo实例失败：", e);
			} finally {
				initialized = true;
			}
		}
	}