Question

How do I get the equivalent of the following Java code (initializing a SLF4J logger) working in JRuby?

private final static Logger logger = LoggerFactory.getLogger(Manager.class);

Let’s say that my (working) example script looks like this:

def test(some_input)
     logger = org.slf4j.LoggerFactory.getLogger("SCRIPT");
     logger.error("Error...")
end

Because I’m a JRuby newbie I only got it working inside the method, and not with a .class in the getLogger.

So the questions are:

• How do I call getLogger using a .class as an argument in the JRuby code?
• How do I put the Logger object somewhere as a static ? I would like to avoid the getLogger every time I call the method.

Thank you for your help!

Answer 1

you’ll need to use java_class to get the “correct” class that is a (wrapped) java.lang.Class and not a ruby class as is with java.util.Date.class e.g. :

Java::OrgSlf4j::LoggerFactory.getLogger java.util.Date.java_class

as for storing it “statically” you could use class variables, but keep in mind that they are shared across the inheritance hierarchy, example :

@@logger = Java::OrgSlf4j::LoggerFactory.getLogger java.util.Date.java_class