org.slf4j.LoggerFactory should be used to obtain a Logger instead of org.apache.commons.logging.LogFactory and com.openexchange.log.LogFactory.

With that an interface of org.slf4j.Logger will be returned instead of org.apache.commons.logging.Log.

There are bridges which will still support the current behaviour but it is recommended to change the factory. For that com.openexchange.log.LogFactory and its methods are marked as deprecated.