On 10-06-21 02:02 PM, Richard S. Hall wrote:
On 6/21/10 14:57, Kelvin Chan wrote:
Hi guys,

I just started with OSGi/Felix and went through a lot of reading over the weekend regarding classloading/osgi/felix. I still don't have a clear idea of how to incorporate an external library into my app.

I understand that OSGi do class loading through Import-Package, no more linear class loading like in an traditional Java app. That means if a bundle does not specify what packages it want to import, it will not be available to that bundle. On the other hand, everything on classpath, if specified by Import-Package, will be available to a bundle. (did I get that right?)

A bundle can only see stuff it imports as long as there is someone else exporting it. For class path packages, the system bundle (i.e., the framework) will export everything in the JRE by default. If you have some other non-JRE packages on the class path that you want bundles to be able to import, then you must add them to the org.osgi.framework.system.packages.extra property in the conf/config.properties file.


This is actually very pertinent to a problem I'm facing as well. I'm trying to get openjpa as a bundle working with mysql, but I keep getting ClassNotFound com.mysql.jdbc.Driver exceptions.

Based on the above info, I changed my launching script (adding the mysql connector jar entry, which I even carefully selected to make sure it has bundling info, although I don't know if that's important) to:

java -splash:/home/jamie/1x1.gif -classpath system/org.apache.felix.karaf/org.apache.felix.karaf.main/1.6.0/org.apache.felix.karaf.main-1.6.0.jar:system/org.apache.felix.karaf.jaas/org.apache.felix.karaf.jaas.boot/1.6.0/org.apache.felix.karaf.jaas.boot-1.6.0.jar:/home/jamie/applications/com.springsource.com.mysql.jdbc/5.1.6/com.springsource.com.mysql.jdbc-5.1.6.jar -Dkaraf.base=$FELBASE -Dkaraf.home=$FELBASE -Dstorage.location=$FELBASE/instances -Dkaraf.default.repository=system -Dkaraf.startLocalConsole=true -Dkaraf.startRemoteShell=false org.apache.felix.karaf.main.Main "$@"

and changed the extra property in etc/config.properties from

org.osgi.framework.system.packages.extra=\
 org.apache.felix.karaf.jaas.boot; version=1.6.0, \
 org.apache.felix.karaf.version; version=1.6.0

to

org.osgi.framework.system.packages.extra=\
 org.apache.felix.karaf.jaas.boot; version=1.6.0, \
 org.apache.felix.karaf.version; version=1.6.0, \
 com.mysql.jdbc;

(Actually I tried both with and without the final trailing ';' )



But, the class not found exceptioning is still occurring :( ... any other stuff I should be changing? It's not an openjpa idiosyncrasy because I traced openjpa to where it's trying to do the resolution and mirrored the resolution code to my own module, specifically

Class getme = Class.forName("com.mysql.jdbc.Driver");

Which goes up the resolution stack ended up in ModuleImpl's findClassOrResourceByDelegation function...

I also tried changing bootdelegation from

org.osgi.framework.bootdelegation=sun.*,com.sun.*,javax.transaction,javax.transaction.*

to

org.osgi.framework.bootdelegation=sun.*,com.sun.*,javax.transaction,javax.transaction.*,com.mysql.jdbc.*


but still no lovin'...

-Jamie

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