Hi Ralph,
I had a dig around to see what might be triggering the log4j configuration
off before the servlet has had a chance to initialise and, I believe it
might be the Spring code itself?
Our deployments are all Spring 4 and java annotation based. i.e. no xml
configuration aside from simple WEB-INF/web.xml file. So, a deployment init
and startup is generally kicked off via the following code:
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.ContextLoaderListener;
import
org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
public class WebInitialiser implements WebApplicationInitializer {
public void onStartup(ServletContext servletContext) throws
ServletException {
// log4j2 web lookup caused by the creation of the rootContext
object.
AnnotationConfigWebApplicationContext rootContext = new
AnnotationConfigWebApplicationContext();
rootContext.register(ApplicationConfig.class,
IntegrationConfig.class, JmsConfig.class, JmxConfig.class);
servletContext.addListener(new ContextLoaderListener(rootContext));
}
}
Now, I think the log4j2's web lookup failure arises because of the creation
of the AnnotationConfigWebApplicationContext class object (If I comment the
creation of that object out, then the servlet starts up okay and log4j2's
web lookup resolves okay too - but of course the servlet is useless as it
no longer has our business code loaded behind it!).
I had a look inside the AnnotationConfigWebApplicationContext class and, I
can see that the class extends
org.springframework.context.support.AbstractApplicationContext which has
the following line:
protected final Log logger = LogFactory.getLog(getClass());.
The Log and LogFactory classes are imported as follows:
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
Can this be the reason why the log4j2 configuration is being scanned before
the servlet context has had a chance to initialise? And therefore log4j2 is
unable to do the web lookup?
The spring-web project does have a web-fragment defined in it called
spring_web and in my deployment's web.xml I have tried including the
following snippet:
<display-name>service-name</display-name>
<absolute-ordering>
<name>log4j</name>
<name>spring_web</name>
<others/>
</absolute-ordering>
But it doesn't solve the web lookup issue. (I am not sure how to prove
whether the fragment ordering is actually being followed during startup
though...)
Any thoughts on any of this would be much appreciated. I have so far not
even have any workarounds for this issue...
Cheers,
PM.
