Willie Wheeler wrote:
> Hi all,
>
> I get package sealing violations when I run my web app on Tomcat 4.0 m3 and
> m4. I never got these with previous releases, and it looks to me as if the
> cause is the addition of the sealed crimson.jar JAR file to the library.
> Problem is that my app uses JDOM b4, which is using Xerces 1.1.2, and Xerces
> contains a bunch of JAXP/DOM/SAX classes that also appear in crimson.jar
> (hence the sealing violation).
> Does anybody have any advice on how best to handle this situation? I guess
> that one way is to remove the duplicate classes from either crimson.jar or
> xerces_1_1_2.jar, but that seems less than ideal, and could easily lead to
> breakage. Maybe some solution involving loading the JARs with different
> class loaders?
>
> Thanks,
> Willie
Welcome to the wonderful world of classloaders :-).
You're correct -- trying to remove classes from one or the other of the JAR files is
not going to work at all. Each library will be depending on its own internal
implementation of those classes.
The crimson.jar file is placed in $CATALINA_HOME/lib (and therefore visible to web
apps) because Jasper needs a JAXP-1.1 compatible parser. It would be technically
feasible for Jasper to load its own XML parser in a private classloader, but this is
not a trivial amount of work. Once Xerces is upgraded to JAXP-1.1 compatibility you
will simply be able to use Xerces instead (and thus not have these conflicts).
If your app does not need JSP, you could simply remove crimson.jar from
$CATALINA_HOME/lib (you will want to comment out the JSP servlet in
$CATALINA_HOME/conf/web.xml as well). If you do, I'm afraid there isn't much that can
be done in the short run until all the parsers catch back up with JAXP compatibility
again.
Craig McClanahan
