configure properly log4j for preventing error messages

[dumoulin]

As log4j isn't correctly configured, we have such a message when we start openmole:

log4j:WARN No appenders could be found for logger (org.apache.commons.configuration.ConfigurationUtils).
log4j:WARN Please initialize the log4j system properly.

It can be fixed programmatically with this code:

org.apache.log4j.Logger.getRootLogger().addAppender(new ConsoleAppender(new PatternLayout("%d %-5p %c - %F:%L - %m%n")));

So we have to put the corresponding log4j.xml configuration file to fix permanently that.

See also these docs:

• http://logging.apache.org/log4j/1.2/manual.html
• http://beuss.developpez.com/tutoriels/java/jakarta/log4j/

[romain.reuillon]

Log4 j used by the apache configuration lib used by the workspace bundle. The message has been fixed by adding the configuration of log4j to the workspace bundle activator.

[dumoulin]

It isn't fixed, as I'm looking for a way to configure loggers with properties or xml file, not programmatically because it needs to rebuild the project.

[dumoulin]

Log4j couldn't be configured as simple as putting a log4j.properties file in a bundle. Creating a fragment is required.

[dumoulin]

As log4j is only used by the module workspace, it is fine to configure it programmatically. In my last commit r2796, I've limited the configuration to the class org.apache.commons.configuration.ConfigurationUtils which uses log4j.