How to track log information in a bean?

Question

I would like to track some information, e.g., variable value, error, in a bean.
I am using System.out.prinln in the bean. I did not see any in the log file of Tomcat5. But this information was shown if from Servelet class.
I also tried to pass error information to class logger, but I do not where the class logger is?
Is it a file somewhere?
Guangming

Answer 1

A good idea is to use something like Log4J to handle logging in your application. You do have to be careful if your application is clustered and there is serialization involved since your logger won't be serializable, causing clustering to fail (I swear it didn't happen to me)....
private transient Logger log = null;
protected final Logger getLogger() {
    if (this.log == null)
        this.log = LogFactory.getLogger(this.getClass());
    return this.log;
}