[jboss-dev] AS ClassLoading in Embedded Environments

Open call for comments/suggestions. I'm running low on ideas. ClassLoading in AS has a few phases: 1) Launch (application classpath, run.jar, some minimal APIs only) 2) Bootstrap (A bunch of JARs in $JBOSS_HOME/lib, enough to start the Kernel and deploy the bootstraps) 3) Service Deployments (jboss-cl takes over, adding in support from $JBOSS_HOME/common as appropriate) In an Embedded environment, the client is in the same JVM as the server. The TCCL of the Main Thread needs to be able to: * Establish a JNDI Context via "new InitialContext();" * Deploy For these, TCCL needs to have access to runtime internals provided via jbossall-client.jar. If this is loaded by a parent CL of something it references, we get NCDFE. For instance: java.lang.NoClassDefFoundError: org/jboss/deployers/vfs/spi/client/VFSDeploymentFactory at org.jboss.embedded.core.server.JBossASEmbeddedServerImpl.deploy(JBossASEmbeddedServerImpl.java:256) Here the AS deployment mechanism is loaded in a ClassLoader higher in the hierarchy than VFS Deployers SPI. I could move where we load VFS Deployers SPI higher up, which would then leak out something else, and on and on. I currently cannot concoct an environment where: * User has a minimal application ClassPath * Other ClassLoading is transparent * Everything works Some attempt to use an isolated ClassLoader result in ClassCastException when equal FQNs end up w/ separate defining ClassLoaders. I believe I'm trying in vain to hack around the underlying problem where the AS module system is not separated out to support this kind of use. We have ClassLoading requirements not being met: * JARs safe for client use at all CL levels (ie. no references to outside dependencies which would also need to be loaded by the same CL) * JARs for compilation only, and runtime will be provided by the container (ie. Maven scope "provided") * JARs used by AS internals *only*. For now I think the only way forward is to either put: 1) Every single one of AS's dependencies on the application ClassPath * http://community.jboss.org/docs/DOC-14441 2) Use a JBossHomeClassLoader which refers out to every AS runtime dependency in $JBOSS_HOME/lib, $JBOSS_HOME/common/lib, and the server libs. S, ALR -- Andrew Lee Rubinger Sr. Software Engineer JBoss by Red Hat http://exitcondition.alrubinger.com http://twitter.com/ALRubinger