Question

In my project I’ve got a top-level abstract class FrameProducer. I added a slf4j logger at this level, so that every inheriting class already has it. Here the code:

public abstract class FrameProducer extends Observable {

    protected final Logger logger = LoggerFactory.getLogger(this.getClass());

    protected BufferedImage frame;

    public BufferedImage getFrame() {
        return frame;
    }

    public void fireEvent() {
        logger.debug("Firing event. Implementing class: {}", this.getClass());
        setChanged();
        notifyObservers();
    }
}

There are also two inheriting classes: CameraFrameGrabber and GrayscaleFilter. Yet, when the method fireEvent() is being called from CameraFrameGrabber or GrayscaleFilter the message is being logged at FrameProducer level. Here the log, for clarity:

FrameProducer.fireEvent - Firing event. Implementing class: class com.ofj.frameaccess.CameraFrameGrabber
FrameProducer.fireEvent - Firing event. Implementing class: class com.ofj.frameaccess.GrayscaleFilter

Is it possible to initialize the logger in FrameProducer in a way that everything gets logged at the most-specialized level in my class hierarchy?

Thanks for any help.

---

Edit: My log4j.properties looks like this:

log4j.rootCategory=TRACE, CONSOLE
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.Threshold=DEBUG
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%C{1}.%M - %m%n

Answer 1

Thanks for pointing out the right direction to look for possible corrections skaffman. I eventually changed my log4j.properties to (as one of the examples in the PatternLayout documentation says):

log4j.rootCategory=TRACE, CONSOLE
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.Threshold=DEBUG
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%-6r [%15.15t] %-5p %30.30c %x - %m%n

…and everything gets logged right.