How to log FATAL (or any custom log level) with SLF4J and Log4j2
I have those specific requirements :
- Need to be able to log in FATAL level
- Need to use SLF4J
- Need to use Log4j2
Right now, here's my implementation:
final Logger logger = LoggerFactory.getLogger(HelloWorld.class);
final Marker marker = MarkerFactory.getMarker("FATAL");
logger.error(marker, "!!! Fatal World !!!");
Here's my PatternLayout (in yaml):
PatternLayout:
Pattern: "%d{ISO8601_BASIC} %-5level %marker [%t] %logger{3.} - %msg%n"
Here's my log output :
20150506T155705,158 ERROR FATAL [main] - !!! Fatal World !!!
Do you have any idea about how to efficiently to remove the "ERROR" from the log output?
Thank you very much
Answer
Marker is not really what you want here. Marker is for "enriching" log messages, making them more easily searchable. You are trying to change the log level/priority, which is a little different.
You're using logger.error() which will log the message as an ERROR level.
If there is no FATAL level pre-defined (usually there is, such as logger.fatal()), then use the generic logger.log() which allows you to specify the log level.
logger.fatal(yourMessage);
OR
logger.log(priorityLevel, yourMessage);
UPDATE:
From the SLF4J website:
The Marker interface, part of the org.slf4j package, renders the FATAL level largely redundant. If a given error requires attention beyond that allocated for ordinary errors, simply mark the logging statement with a specially designated marker which can be named "FATAL" or any other name to your liking.
http://www.slf4j.org/faq.html#fatal
So, with SLF4J, it is not possible to have a FATAL log level. I strongly disagree with the rationale behind this decision, but it is what it is.