My two cents as a Log4J User.
I use Log4J in my servlets and I think it great. Logging has never been so easy.
One issue though, the Configurator class holds it data in a Static variable so
two servlets inside the same JVM will each over write the others config. Even
since I implemented Log4J I was worried that my servlets may not play well
with others when trying to deploy at an ISP. Also will you be able to support
one Servlet using a PropertyConfigurastion as opposed to a XMLConfigurator.
A word to the wise, one of our biggest hurdles was where or when to use each
level. i.e. Debug,Info,warn.. It is easy to always use Info or Debug which defeats
the purpose of separate levels. We had to create a standards document that defined
where to implement each. It was surprising how often I need to look at the document
to make the right choice.
Regards
John G
Ceki Glc wrote:
Hello,
I am toying with the idea of migrating catalina logging to log4j. Let me begin by
saying that I am far from being familiar with catalina internals but I am getting
there slowly.
After a short initial study and some experimentation, here are some tentative
conclusions:
1) The way logging is done currently in catalina is not optimal or, in plain
English, sucks. Like most project using their own logging API, there are real
benefits in using a more specialized package like log4j instead of the home-brewed
solution. More on this below.
2) Since catalina uses its own class loader, it would be possible to have catalina
use log4j for logging without affecting other parts of Tomcat. This is probably not
entirely true since Tomcat uses a logging hierarchy. I'll ignore this issue for the
time being until I understand the implications. More importantly, existing servelets
using log4j will be unaffected because they will be using a classloader in a
different branch of the cl-tree.
Benefits of the move to log4j would be:
- No more need to do
if(debug 1)
log("Some message");
instead one would write
log.debug("Some message");
where log is an instance of org.apache.log4j.Category.
- No more need to have a log() method in each catelina class, as in
private static void log(String message) {
System.out.print("Bootstrap: ");
System.out.println(message);
}
in Bootstrap.java. Log4j would use the category name to identify the source of the
log statement.
- Instead of
try {
} catch (IOException e) {
System.out.println("Cannot create URL for " +
filenames[i]);
e.printStackTrace(System.out);
}
one would write
try {
} catch (IOException e) {
log.error("Cannot create URL for " + filenames[i], e);
}
One advantage is that the code becomes shorter. More importantly, the error can be
reported to any defined log4j appender attached to "log" category instance not just
to System.out.
- The user would configure logging in Tomcat using a separate configuration file,
simplifying the actual Tomcat configuration. I am assuming that the DTD for
sevlet.xml is not part of the Servlet spec so it can be modified without fear of
contradicting the spec.
Anyway, I am still studying the problem but it looks pretty encouraging for the
moment. Your comments are welcome. Ceki
--
Ceki Glc
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John Gentilin
Eye Catching Solutions Inc.
18314 Carlwyn Drive
Castro Valley CA 94546
Contact Info
[EMAIL PROTECTED]
Phone 1-510-881-4821
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