Remote EJB Call throws a java.lang.ClassNotFoundException - jboss

Question

I am getting a following exception in the client, this exception comes very rarely though.
If the class is not found, then this error should come every time, but this error comes very rarely.
We have our swing application deployed on jboss 5.1 server.
We have two main components :
Client- The client code that communicates with the server and renders the Java Swing components.
Server- The server code responsible for sending the screen and event data to the client.
Client communicates with the server using a EJB Container.
Stacktrace :
java.lang.ClassNotFoundException: com.tools.project.server.CustomUtil
at org.jboss.remoting.serialization.ClassLoaderUtility.loadClass(ClassLoaderUtility.java:103)
at org.jboss.remoting.loading.RemotingClassLoader.loadClass(RemotingClassLoader.java:86)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at org.jboss.remoting.loading.ObjectInputStreamWithClassLoader.resolveClass(ObjectInputStreamWithClassLoader.java:179)
at java.io.ObjectInputStream.readNonProxyDesc(Unknown Source)
at java.io.ObjectInputStream.readClassDesc(Unknown Source)
at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
at java.io.ObjectInputStream.readObject0(Unknown Source)
at java.io.ObjectInputStream.defaultReadFields(Unknown Source)
at java.io.ObjectInputStream.readSerialData(Unknown Source)
at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
at java.io.ObjectInputStream.readObject0(Unknown Source)
at java.io.ObjectInputStream.readObject(Unknown Source)
at org.jboss.remoting.serialization.impl.java.JavaSerializationManager.receiveObjectVersion2_2(JavaSerializationManager.java:238)
at org.jboss.remoting.serialization.impl.java.JavaSerializationManager.receiveObject(JavaSerializationManager.java:138)
at org.jboss.remoting.marshal.serializable.SerializableUnMarshaller.read(SerializableUnMarshaller.java:123)
at org.jboss.remoting.transport.socket.MicroSocketClientInvoker.versionedRead(MicroSocketClientInvoker.java:1220)
at org.jboss.remoting.transport.socket.MicroSocketClientInvoker.transport(MicroSocketClientInvoker.java:850)
at org.jboss.remoting.MicroRemoteClientInvoker.invoke(MicroRemoteClientInvoker.java:165)
at org.jboss.remoting.Client.invoke(Client.java:1724)
at org.jboss.remoting.Client.invoke(Client.java:629)
at org.jboss.aspects.remoting.InvokeRemoteInterceptor.invoke(InvokeRemoteInterceptor.java:60)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
at org.jboss.aspects.remoting.ClusterChooserInterceptor.invoke(ClusterChooserInterceptor.java:84)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
at org.jboss.aspects.tx.ClientTxPropagationInterceptor.invoke(ClientTxPropagationInterceptor.java:61)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
at org.jboss.ejb3.security.client.SecurityClientInterceptor.invoke(SecurityClientInterceptor.java:65)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
at org.jboss.ejb3.remoting.ClusteredIsLocalInterceptor.invoke(ClusteredIsLocalInterceptor.java:54)
at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
at org.jboss.aspects.remoting.PojiProxy.invoke(PojiProxy.java:62)
at $Proxy3.invoke(Unknown Source)
at org.jboss.ejb3.proxy.impl.handler.session.SessionProxyInvocationHandlerBase.invoke(SessionProxyInvocationHandlerBase.java:207)
at org.jboss.ejb3.proxy.impl.handler.session.SessionProxyInvocationHandlerBase.invoke(SessionProxyInvocationHandlerBase.java:164)
at $Proxy2.getMessagingBuffer(Unknown Source)

Answer 1

The error will only occur when the server sends an object to the client that references a com.tools.project.server.CustomUtil. Either add com.tools.project.server.CustomUtil to the client class loader or remove the reference from the server response.