You can use these:
BLTHContext.logWarningMessage("Print ...",true);
BLTHContext.logErrorMessage("Print ...",true);
BLTHContext.logInfoMessage("Print ...",true);
BLTHContext.logDebugMessage("Print ...",true);
Under default logging App Server settings, warning will show the msg inside server.log: BLTHContext.logWarningMessage("Print ...",true);
Regards,
Sumeet