Mixin class at the class level

[claudehussenet]

1/Is there a way to apply a mixin class at the class level and not
only at the instance level ?

2/It looks like that the same mixin class can be instantiated more than
once per instance based on class inheritance.

For example :
if the class A inherits from class B and both supposed to have attached the mixin class C,when I create an instance of A,two instances of C are created .Is is expected ?

Rgds-Claude

[claudehussenet]

1) PER-VM and PER-Instance are supported. It would be per-class that would have to be supported.

[bill.burke]

addNotificationListener on an RMIAdaptor throws the following exception when adding the notification listener I put in my previous message:

java.rmi.MarshalException: error marshalling arguments; nested exception is:
 java.io.NotSerializableException: be.ugent.pbackx.client.MyRMIListener
 at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:129)
 at org.jboss.invocation.jrmp.server.JRMPInvoker_Stub.invoke(Unknown Source)
 at org.jboss.invocation.jrmp.interfaces.JRMPInvokerProxy.invoke(JRMPInvokerProxy.java:135)
 at org.jboss.invocation.InvokerInterceptor.invoke(InvokerInterceptor.java:96)
 at org.jboss.jmx.connector.invoker.client.InvokerAdaptorClientInterceptor.invoke(InvokerAdaptorClientInterceptor.java:58)
 at org.jboss.proxy.SecurityInterceptor.invoke(SecurityInterceptor.java:53)
 at org.jboss.proxy.ClientMethodInterceptor.invoke(ClientMethodInterceptor.java:55)
 at org.jboss.proxy.ClientContainer.invoke(ClientContainer.java:85)
 at $Proxy1.addNotificationListener(Unknown Source)
 at be.ugent.pbackx.util.EJBUtil.addNotificationListener_aroundBody82(EJBUtil.java:143)
 at be.ugent.pbackx.util.EJBUtil.addNotificationListener_aroundBody84(EJBUtil.java:143)
 at be.ugent.pbackx.util.EJBUtil.addNotificationListener(EJBUtil.java)
 at be.ugent.pbackx.client.SimpleMonitorPanel.<init>(SimpleMonitorPanel.java:36)
 at be.ugent.pbackx.client.GUIManager.initComponents_aroundBody122(GUIManager.java:83)
 at be.ugent.pbackx.client.GUIManager.initComponents(GUIManager.java)
 at be.ugent.pbackx.client.GUIManager.initComponents_aroundBody0(GUIManager.java:26)
 at be.ugent.pbackx.client.GUIManager.<init>(GUIManager.java:26)
 at be.ugent.pbackx.client.GUIManager.main(GUIManager.java:171)
Caused by: java.io.NotSerializableException: be.ugent.pbackx.client.MyRMIListener
 at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1054)
 at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1224)
 at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1050)
 at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:278)
 at org.jboss.invocation.MarshalledValue.<init>(MarshalledValue.java:57)
 at org.jboss.invocation.MarshalledInvocation.writeExternal(MarshalledInvocation.java:477)
 at java.io.ObjectOutputStream.writeExternalData(ObjectOutputStream.java:1264)
 at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1245)
 at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1052)
 at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:278)
 at sun.rmi.server.UnicastRef.marshalValue(UnicastRef.java:265)
 at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:124)
 ... 17 more

Just for the record the complete MyRMIListener code:

package be.ugent.pbackx.client;

import org.jboss.jmx.adaptor.rmi.RMINotificationListener;

public class MyRMIListener implements RMINotificationListener {
 public void handleNotification(javax.management.Notification notification, Object obj) {
 System.out.println("\nReceived notification: " + notification);
 }
}

[bill.burke]

1) If you want a singleton mixin, then you can put anything you want in the construction XML element. So, the mixin reference can be set by calling a method or setting it to a singleton field of some class.

2) Are you applying the introduction twice? How does C++ work? I want to model virtual inheritance of C++ so I guess I have to change the behavior. As a workaround, I guess you have to make sure that the introduction expression has a !$instanceof{MixinInterface}

Bill

[claudehussenet]

1/OK for the workaround.
Do u think that the scope for a Mixin class could not be supported
at the infrastructure level ?(future version of JBOSS-AOP)

2/ Thx .It does work...FYI ,the full expression for my user-case.

[bill.burke]

1) PER-VM and PER-Instance are supported. It would be per-class that would have to be supported.

[claudehussenet]

Any plan to support per class scope for Introduction in the near future ?
Thx Claude

FYI.,what Aspectwerkz does in this area :

<introduction-def name="mixin"
interface="examples.introduction.Mixin"
implementation="examples.introduction.MixinImpl"
deployment-model=perJVM | perClass | perInstance | perThread />