Ceki,
This is welcome news!
It isn't clear to me whether the standard servlet API logging methods could use log4j
behind the scense to do logging. This would be very nice, especially if you could
configure log4j logging for each scope (Engine, Host, DefaultContext, Context) in
server.xml.
And even configure different destinations for different types of message levels.
Regards,
Glenn
Ceki Gülcü 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 Gülcü
--
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Glenn Nielsen [EMAIL PROTECTED] | /* Spelin donut madder |
MOREnet System Programming | * if iz ina coment. |
Missouri Research and Education Network | */ |
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