How to use loggers (log4j or other) in rules depoyed in the Kie server ?

[simplex-software]

Hello,

I found several samples showing how to use a logger in rules, by passing an instance of it in the kie session, etc. But I don't know how to do it in rules executed in the Kie server and called like this:

  KieServicesClient client = KieServicesFactory.newKieServicesRestClient("http://localhost:8080/kie-server/services/rest/server", "user", "password");

ServiceResponse<String> response = client.executeCommands("container-0", payload);

Given that this code doesn't handle the Kie session such that to pass, in it, an instance of the logger to the rules, I don't know how to use a logger defined like this:

import org.apache.log4j.Logger;

global Logger LOGGER;

...........................

  LOGGER.debug ("HelloWorld *****");      // NullPointerException

Many thanks i advance for any help.

Nicolas

[simplex-software]

The following seems to work:

global Logger LOGGER;

rule ....

......................

when

......................

then

  LOGGER = Logger.getLogger("...");

  LOGGER.debug ("HelloWorld *****");

.......................

Of course, this is not exactly the right way to do it as the logger has to be instantiated in each rule. This is because the following:

global Logger LOGGER = Logger.getLogger("...");

raises compilation errors.

So, I'm looking for suggestions of how to better use log4j in rules.

[jjfd]

I guess you can instantiate the logger outside the rules, and then use

ksession.setGlobal("logger", logger);