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From "???" <>
Subject Re: CLASSPATH precedence
Date Tue, 19 Dec 2000 06:12:22 GMT

For tomcat 3.2 (tomcat 4.0 is different), the classes from $TOMCAT_HOME/webapps/WEBAPP_A/WEB-INF/lib
and $TOMCAT_HOME/webapps/WEBAPP_A/WEB-INF/classes sont loaded by a custome classloader. The
classes from system CLASSPATH sont loaded by the system classloader. The class loading is
in the following order: 1) BootStrap; 2)Extension; 3) System Classpath; 4) special directories
known by the custom classloader, so

1) the classes in $TOMCAT_HOME/webapps/WEBAPP_A/WEB-INF/lib
 and in $TOMCAT_HOME/webapps/WEBAPP_B/WEB-INF/lib sont completly different.

2) The classes in the system CLASSPATH take precedence.



----- Original Message ----- 
From: "David Miller" <>
To: <>
Sent: Tuesday, December 19, 2000 4:19 AM
Subject: CLASSPATH precedence

> Hi,
> Two related questions regarding CLASSPATH precedence:
> (A) If I place the same *.jar files (same names but different versions)
> in both
>                 $TOMCAT_HOME/webapps/WEBAPP_A/WEB-INF/lib
> and in     $TOMCAT_HOME/webapps/WEBAPP_B/WEB-INF/lib
> does the version of the *.jar files in WEBAPP_A or in WEBAPP_B take
> precedence? Or does it depend on which context I am in (i.e., which
> webapp tomcat is running). How does tomcat figure out which version of
> the *.jar files to use? Do classes loaded from one *.jar file get
> unloaded if I am running in a different context?
> (B) (similar question but for system *.jar files vs tomcat *.jar files):
> If I place the same *.jar files (same names but different versions) in
> both
>                 $TOMCAT_HOME/webapps/WEBAPP_A/WEB-INF/lib
> and in my system CLASSPATH
> which version of the *.jar files take precedence when I am running ?
> Any answers/information regarding these two questions is greatly
> appreciated, especially ones which shed some light on how tomcat figures
> out which version of classes to load. Thanks,
> -David-

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