NoClassDefFoundError in shutdown hook ------------------------------------- Key: JBASMP-61 URL: https://issues.jboss.org/browse/JBASMP-61 Project: JBoss AS Maven Plugins Issue Type: Bug Affects Versions: 7.5.Final Environment: Maven 3.1.1, Oracle JDK 1.7.0_45. Reporter: Vlad Arkhipov Assignee: James Perkins {code} <build> <plugins> <plugin> <groupId>org.jboss.as.plugins</groupId> <artifactId>jboss-as-maven-plugin</artifactId> <version>7.5.Final</version> <executions> <execution> <id>start-jboss</id> <goals> <goal>start</goal> </goals> <phase>package</phase> <configuration> <jbossHome>/home/user/jboss</jbossHome> </configuration> </execution> </executions> </plugin> </plugins> </build>{code} If jbossHome is specified, the following exception occurs {code}Exception in thread "Thread-2" java.lang.NoClassDefFoundError: org/jboss/as/plugin/common/IoUtils at org.jboss.as.plugin.server.StandaloneServer.stopServer(StandaloneServer.java:77) at org.jboss.as.plugin.server.Server.stop(Server.java:108) at org.jboss.as.plugin.server.SecurityActions$1.run(SecurityActions.java:41) at java.lang.Thread.run(Thread.java:724) Caused by: java.lang.ClassNotFoundException: org.jboss.as.plugin.common.IoUtils at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:50) at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass(ClassRealm.java:259) at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:235) at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:227){code} The reason is that in the shutdown hook the class loader is already closed by Maven and cannot be used to load new classes. DefaultPlexusContainer.dispose() disposes plugins' ClassRealms and closes associated URLClassLoaders (if Java version is 7+). {code}ClassRealm(URLClassLoader).close() line: 282 ClassWorld.closeIfJava7(ClassRealm) line: 113 ClassWorld.disposeRealm(String) line: 97 DefaultPluginRealmCache.flush() line: 189 DefaultPluginRealmCache.dispose() line: 216 PlexusLifecycleManager.dispose(Disposable) line: 408 PlexusLifecycleManager.unmanage() line: 193 DefaultPlexusContainer.dispose() line: 586 MavenCli.doMain(MavenCli$CliRequest) line: 241 MavenCli.main(String[], ClassWorld) line: 158 {code} As a temporary workaround you can either preload IoUtils class somewhere before Maven shutdowns (which is brittle) or "respawn" the current classloader in shutdown hook (which is hacky and brittle too). Shutdown hooks should be avoided in plugins as Maven documentation says: http://maven.apache.org/plugin-developers/common-bugs.html#Using_Shutdown.... But it seems there is currently no way to handle Maven shutdown event in a plugin, isn't it?