 | Mailing List | | Home | | Forum Home | | JBoss - Java Application Server | | Tomcat - JSP/Servlet container | | Struts - A MVC web framework | | iText - An open source PDF Java Library | | JDOM - JDOM XML Parser | | J2EE - A mailing list for Java(tm) 2 Platform, Enterprise Edition | | J2EE Pattern - An interest list for Sun Java Center J2EE Pattern Catalog | | JSP - A mailing list about Java Server Pages specification and reference | | Servlet - A mailing list for discussion about Sun Microsystem's Java Servlet API Technology | |
Struts & Hibernate
|
|
|
| | | How to use logging in Tomcat correctly (declare Logger Static or not) ? | How to use logging in Tomcat correctly (declare Logger Static or not) ? 2006-11-17 - By Mon Cab
Back
>
> Good day
>
> I am having a hard time understanding how to use commons logging on
Tomcat. The struts.apache.org suggest the following usage (presumably
for business objects) (taken from:
> http://struts.apache.org/1.x/userGuide/building_controller.html )
>
>
> package com.foo;
> // ...
> import org.apache.commons.logging.Log  ;
> import org.apache.commons.logging.LogFactory ;
> ...
> public class User {
> // ...
> private static Log log =
> LogFactory.getLog(User.class);
> // ...
> public void setBar(Bar bar) {
>
> log.trace("Setting bar to " + bar);
> this.bar = bar;
> }
> // ...
> }
>
>
> The suggestion seems to be that it is OK to declare my Logger as a
> static variable in the business object. This is ideal for me
> because,
> I will be accessing the Logger from both instance and static methods,
> and so I do not want to have to declare this as an instance variable.
>
>
> However, I am wondering whether this is OK, given that my business
> objects will be being accessed from different servlet threads. Can
> anyone tell me whether this is OK?, and if not, what is the correct
> way
> to do this?
>
> My second question is whether the same usage is valid for Action (or
servlet) classes. I saw the following example, at
>
http://www.mobilefish.com/developer/struts/struts_quickguide_log4j.html
> but am not certain as to whether using a static variable would be OK
> here. Would it?
>
> public class DemoServlet extends Servlet {
>
> private static Log log =
> LogFactory.getLog("com.mobilefish.DemoAction");
>
> public service etc etc {}
> }
>
> The commons logging documentation notes the following:
>
> Note that for application code, declaring the log member as "static"
> is
> more efficient as one Log object is created per class, and is
> recommended. However this is not safe to do for a class which may be
> deployed via a "shared" classloader in a servlet or j2ee container or
> similar environment. If the class may end up invoked with different
> thread-context-classloader values set then the member must not be
> declared static. The use of "static" should therefore be avoided in
> code within any "library" type project.
>
> I'm not clear as to what the above means, from a practical
> perspective
> in the context of a web applicaiton. What does this mean in simple
> terms?
>
> Taken from:
>
http://jakarta.apache.org/commons/logging/guide.html#Configuring_Log4J
>
>
>
>
>
>
>
__ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ______
__ __
> The all-new Yahoo! Mail beta
> Fire up a more powerful email and get things done faster.
> http://new.mail.yahoo.com
>
>
__ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ______
__ __
Sponsored Link
$420k for $1,399/mo.
Think You Pay Too Much For Your Mortgage?
Find Out! www.LowerMyBills.com/lre
-- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ------
To start a new topic, e-mail: users@(protected)
To unsubscribe, e-mail: users-unsubscribe@(protected)
For additional commands, e-mail: users-help@(protected)
|
|
|
