3 Replies Latest reply on May 26, 2009 8:08 PM by triumphthepup

JBoss 5 ClassLoading

angusm May 19, 2009 11:37 AM

This is a plea for someone to explain JBoss 5 Classloading. According to Ales Justin, in this forum, the Unified Class Loader no longer exists. So (my understanding would be) all previous Wiki articles on Class Loading are now obsolete. Notably http://www.jboss.org/community/wiki/JBossClassLoadingUseCases.
The only article on JBoss 5 class loading I have found is http://www.jboss.org/community/wiki/useJBossWebClassLoaderinJBoss5 (and incidentally I have not found any direct references to it, outside JIRA).

I would have said that it did not necessarily need a core developper to do this; but maybe the subject is so complicated that it does.

I know you guys are really busy, and work really long hours; but anything would be appreciated.

Not surprisingly, perhaps, Scott Stark's getClassLoaders method is not very revealing with JBoss 5.
On JBoss 5.0.1:

16:54:36,015 INFO [STDOUT] +++ org.jboss.web.tomcat.service.WebCtxLoader$ENCLoader@f051af
+++ BaseClassLoader@cc9ff5{vfszip:/C:/Other/eclipseall/ws/hsi/test-servlet/releasePackage/toast.war/}

On JBoss 4.2.2:

17:31:01,906 INFO [STDOUT] +++ org.jboss.web.tomcat.service.WebCtxLoader$ENCLoader@12c55fd
+++ java.net.FactoryURLClassLoader@166e555
+++ org.jboss.mx.loading.UnifiedClassLoader3@11199f0{ url=file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/de
loy/tmp26489toast-exp.war/ ,addedOrder=53}
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/log4j.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26419trove.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/commons-collections.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/hibernate3.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/cglib.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26478jms-ra.rar-contents/jms-ra.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss-monitoring.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jnpserver.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26423jboss-microcontainer.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/activation.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/el-api.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss-vfs.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/bcel.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26422jboss-dependency.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26446wsdl4j.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/antlr.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jbosssx.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/commons-httpclient.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26478jms-ra.rar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26475jboss-ha-xa-jdbc.rar-contents/jboss-ha-xa-
dbc.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26480quartz-ra.rar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26440jaxb-impl.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/dom4j.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/jbossws.sar/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jmx-adaptor-plugin.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss-common-jdbc-wrapper.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/hsi-appender.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/servlet-api.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss-jsr77.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/mail.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26428jboss-faces.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26430jsf-impl.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26447wstx.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/scheduler-plugin.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/jbossws.sar/jbossws.beans/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss-hibernate.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/jmx-console.war/WEB-INF/classes/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/jboss-web.deployer/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/http-invoker.sar/invoker.war/WEB-INF/classes/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/jboss-web.deployer/ROOT.war/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26489toast-exp.war/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26436hsi-monitor.sar-contents/mbean.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/commons-codec.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss-transaction.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/uuid-key-generator.sar/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss-cache.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/juddi-service.sar/juddi.war/WEB-INF/classes/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/http-invoker.sar/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jbossjta.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26450juddi-service.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/commons-logging.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/bindingservice-plugin.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26417jboss-aop-jdk50.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/log4j-snmp-appender.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26420jboss-bean-deployer.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/javassist.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26452scout.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss-management.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss-srp.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26476jboss-local-jdbc.rar-contents/jboss-local-
dbc.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jpl-util.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jbossws-native-jaxws-ext.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26415jboss-annotations-ejb3.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/bsf.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/jms/jbossmq-httpil.sar/jbossmq-httpil.war/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26477jboss-xa-jdbc.rar-contents/jboss-xa-jdbc.j
r
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26443jettison.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26429jsf-api.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26477jboss-xa-jdbc.rar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26436hsi-monitor.sar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/mail-plugin.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26451juddi.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss-ejb3x.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/slf4j-api-1.5.0.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jsp-api.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26441jboss-jaxb-intros.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jbossws-native-jaxws.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26425jbossweb-extras.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/hibernate-entitymanager.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26421jboss-container.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26475jboss-ha-xa-jdbc.rar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/jms/jbossmq-httpil.sar/jbossmq-httpil.war/WEB-INF/clas
es/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/hibernate-annotations.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss-j2ee.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26438FastInfoset.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/slf4j-log4j12-1.5.0.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jbossws-common.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/ejb3.deployer/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26479mail-ra.rar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jbossts-common.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss-jca.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26418jboss-aspect-library-jdk50.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jbossws-native-saaj.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26442jbossws-native-core.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26424jasper-jdt.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26489toast-exp.war/WEB-INF/classes/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss-serialization.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/jmx-console.war/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/bsh.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jgroups.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jbossws-jboss422.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/jbossws.sar/jbossws-management.war/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/xmlentitymgr.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/juddi-service.sar/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26439jaxb-api.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jbossws-framework.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/mysql-connector-java-5.0.7-bin.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26449juddi-saaj.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/hsqldb-plugin.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jbossws-spi.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26416jboss-ejb3.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26437jboss-profiler.sar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/joesnmp.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jpl-pattern.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jbossws-native-jaxrpc.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26479mail-ra.rar-contents/mail-ra.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/autonumber-plugin.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/properties-plugin.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/jbossws.sar/jbossws-management.war/WEB-INF/classes/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jbossjta-integration.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26476jboss-local-jdbc.rar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26445stax-api.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss-remoting.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jbossmq.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss-jsr88.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/ejb3-persistence.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/http-invoker.sar/invoker.war/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/bsh-deployer.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26480quartz-ra.rar-contents/quartz-ra.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26444policy.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/jms/jbossmq-httpil.sar/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26474jboss-ha-local-jdbc.rar-contents/jboss-ha-
ocal-jdbc.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/hsqldb.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26427jbossweb.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/juddi-service.sar/juddi.war/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26448xmlsec.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26431jstl.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/mina-core-2.0.0-M2.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/scheduler-plugin-example.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/jboss-bean.deployer/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/mina-core-2.0.0-M3.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jboss-remoting-int.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26474jboss-ha-local-jdbc.rar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/conf/
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/quartz.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/tmp/deploy/tmp26426jbossweb-service.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/lib/jaxen.jar
 - file:/C:/jboss/jboss-4.2.2.GA/server/default/deploy/jboss-aop-jdk50.deployer/
+++ org.jboss.system.server.NoAnnotationURLClassLoader@78a212
 - file:/C:/jboss/jboss-4.2.2.GA/lib/endorsed/serializer.jar
 - file:/C:/jboss/jboss-4.2.2.GA/lib/endorsed/xalan.jar
 - file:/C:/jboss/jboss-4.2.2.GA/lib/endorsed/xercesImpl.jar
 - file:/C:/jboss/jboss-4.2.2.GA/lib/jboss-jmx.jar
 - file:/C:/jboss/jboss-4.2.2.GA/lib/concurrent.jar
 - file:/C:/jboss/jboss-4.2.2.GA/lib/log4j-boot.jar
 - file:/C:/jboss/jboss-4.2.2.GA/lib/jboss-common.jar
 - file:/C:/jboss/jboss-4.2.2.GA/lib/jboss-system.jar
 - file:/C:/jboss/jboss-4.2.2.GA/lib/jboss-xml-binding.jar
+++ sun.misc.Launcher$AppClassLoader@9fbe93
 - file:/C:/jboss/jboss-4.0.5.GAejb3/server/default/lite
 - file:/C:/Sun/AppServer/jdk/lib/tools.jar
 - file:/C:/jboss/jboss-4.2.2.GA/bin/run.jar
+++ sun.misc.Launcher$ExtClassLoader@198dfaf
 - file:/C:/Sun/AppServer/jdk/jre/lib/ext/dnsns.jar
 - file:/C:/Sun/AppServer/jdk/jre/lib/ext/localedata.jar
 - file:/C:/Sun/AppServer/jdk/jre/lib/ext/sunjce_provider.jar
 - file:/C:/Sun/AppServer/jdk/jre/lib/ext/sunpkcs11.jar

private static String getClassLoaders() {
 ClassLoader loader = Thread.currentThread().getContextClassLoader();
 StringBuffer buffer = new StringBuffer();
 boolean sawUnifiedClassLoader = false;
 do {
 buffer.append("+++ ");
 buffer.append(loader);
 buffer.append('\n');
 String loaderName = loader.getClass().getName();
 boolean isUCL = loaderName.startsWith("org.jboss.");
 // if (isUCL && sawUnifiedClassLoader == false) {
 if (isUCL) {
 sawUnifiedClassLoader = true;
 // Only add the UnifiedLoaderRepository.getURLs info once
 URL[] paths = null;
 try {
 Method getAllURLs = loader.getClass().getMethod("getAllURLs", new Class[0]);
 paths = (URL[]) getAllURLs.invoke(loader, new Object[0]);
 } catch (Exception e) {
 }
 int length = paths == null ? 0 : paths.length;
 for (int p = 0; p < length; p++) {
 buffer.append(" - ");
 buffer.append(paths[p]);
 buffer.append('\n');
 }
 } else if (loader instanceof URLClassLoader) {
 URLClassLoader uloader = (URLClassLoader) loader;
 URL[] paths = uloader.getURLs();
 int length = paths == null ? 0 : paths.length;
 for (int p = 0; p < length; p++) {
 buffer.append(" - ");
 buffer.append(paths[p]);
 buffer.append('\n');
 }
 }
 if (loader != null)
 loader = loader.getParent();
 } while (loader != null);
 // Write the call stack
 buffer.append("+++ Call stack:\n");
 Throwable t = new Exception("Don't panic, just a stack trace");
 StringWriter sw = new StringWriter();
 PrintWriter pw = new PrintWriter(sw);
 t.printStackTrace(pw);
 buffer.append(sw.toString());
 return buffer.toString();
 }

1. Re: JBoss 5 ClassLoading

alrubinger May 19, 2009 11:43 AM (in response to angusm)

From a high level, check how CL ties into MC Deployments:

http://jboss.org/file-access/default/members/jbossmc/freezone/docs/2.0.x/userGuide/ch10s01.html

S,
ALR
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2. Re: JBoss 5 ClassLoading

alesj May 19, 2009 12:47 PM (in response to angusm)

http://www.jboss.org/community/wiki/JBossClassLoaderHistory
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3. Re: JBoss 5 ClassLoading

triumphthepup May 26, 2009 8:08 PM (in response to angusm)

I second the call for a page that documents classloading in JBoss 5+, optimally from a JEE perspective (which I assume is how most people are using it).

The documentation on how classloaders work in the MC is only helpful if you understand how the MC relates to JEE (EARs, EJBs, WARs, etc.). The wiki page on the history of classloading in the JBoss is helpful, but it is more of a feature list for the new classloader design and doesn't explain the hierarchy or the preferred methods for configuring it.

It would be really helpful to have a single Wiki page that illustrated classloading in JBoss 5+ and communicated which, if any of the existing Wiki pages are still relevant going forward.

I would do this myself, but I'm still trying to figure out classloading in Jboss 5 ;)
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