We tried the following steps for implementing classpath isolation in jBoss 4.2 (but not working as expected). First, edit the conf/jboss-service.xml file and set the NamingService CallByValue to true: <!-- The call by value mode. true if all lookups are unmarshalled using the caller's TCL, false if in VM lookups return the value by reference. --> true ... Second, edit the deploy/ear-deployer.xml file and set the Isolated and CallByValue attributes to true: <!-- EAR deployer, remove if you are not using ear deployments --> <!-- A flag indicating if ear deployments should have their own scoped class loader to isolate their classes from other deployments. --> true <!-- A flag indicating if the ear components should have in VM call optimization disabled. --> true Last, edit the deploy/jboss-web.deployer/META-INF/jboss-service.xml file and set the Java2ClassLoadingCompliance and UseJBossWebLoader attributes to false: <!-- Get the flag indicating if the normal Java2 parent first class loading model should be used over the servlet 2.3 web container first model. --> false true <!-- A flag indicating if the JBoss Loader should be used. This loader uses a unified class loader as the class loader rather than the tomcat specific class loader. --> false ----------------- The exception we are getting are as follows---------------- 2009-01-01 00:30:41,000 ERROR [STDERR] Caused by: java.io.InvalidClassException: org.apache.commons.collections.map.ListOrderedMap; class invalid for deserialization 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:571) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1552) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1466) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1699) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1908) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1832) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.readObject(ObjectInputStream.java:348) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.util.HashMap.readObject(HashMap.java:1067) 2009-01-01 00:30:41,000 ERROR [STDERR] at sun.reflect.GeneratedMethodAccessor269.invoke(Unknown Source) 2009-01-01 00:30:41,000 ERROR [STDERR] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.lang.reflect.Method.invoke(Method.java:585) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:946) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1809) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1908) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1832) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305) 2009-01-01 00:30:41,000 ERROR [STDERR] at java.io.ObjectInputStream.readObject(ObjectInputStream.java:348) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4199450#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...