RE: "Cannot serialize session attribute ..."

[Leffingwell, Jonathan R CTR FRCSE, JAX 7.2.2]

What does that mean, "set reference to it transient"?


-----Original Message-----
From: Nicholoz Koka Kiknadze [mailto:kikna...@gmail.com] 
Sent: Thursday, March 19, 2009 3:30 PM
To: user-java@ibatis.apache.org
Subject: Re: "Cannot serialize session attribute ..."

My first thought is that maybe StandardDaoManager can not be serializable as
it deals with database connections. Maybe makes sense to set reference to it
transient?







On Thu, Mar 19, 2009 at 2:55 PM, Leffingwell, Jonathan R CTR FRCSE, JAX
7.2.2 <jonathan.leffingwell....@navy.mil> wrote:


        I am running a web app in IBM RAD 7 with a Tomcat 5.5.26 server,
with
        clustering (two Tomcat instances).  When shutting down the Tomcat
server(s),
        I get the following warning:
        
        Mar 19, 2009 2:52:43 PM org.apache.catalina.session.StandardSession
        writeObject
        WARNING: Cannot serialize session attribute createXXXManager for
session
        8B1876E5C5C54B242E4256674843600B
        java.io.NotSerializableException:
        com.ibatis.dao.engine.impl.StandardDaoManager
               at
        
java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1081)
               at
        
java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1375)
               at
        
java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1347)
               at
        
java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1290)
               at
        
java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1079)
               at
        java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:302)
               at
        
org.apache.catalina.session.StandardSession.writeObject(StandardSession.java
        :1478)
               at
        
org.apache.catalina.session.StandardSession.writeObjectData(StandardSession.
        java:948)
               at
        
org.apache.catalina.session.StandardManager.doUnload(StandardManager.java:51
        7)
               at
        
org.apache.catalina.session.StandardManager.unload(StandardManager.java:463)
               at
        
org.apache.catalina.session.StandardManager.stop(StandardManager.java:667)
               at
        
org.apache.catalina.core.StandardContext.stop(StandardContext.java:4360)
               at
        org.apache.catalina.core.ContainerBase.stop(ContainerBase.java:1067)
               at
        org.apache.catalina.core.ContainerBase.stop(ContainerBase.java:1067)
               at
        
org.apache.catalina.core.StandardEngine.stop(StandardEngine.java:448)
               at
        
org.apache.catalina.core.StandardService.stop(StandardService.java:510)
               at
        
org.apache.catalina.core.StandardServer.stop(StandardServer.java:734)
               at
org.apache.catalina.startup.Catalina.stop(Catalina.java:602)
               at
org.apache.catalina.startup.Catalina.start(Catalina.java:577)
               at sun.reflect.NativeMethodAccessorImpl.invoke0(Native
Method)
               at
        
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39
        )
               at
        
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl
        .java:25)
               at java.lang.reflect.Method.invoke(Method.java:585)
               at
org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:295)
               at
org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:433)
        
        
        All of my managers, including createXXXManager, inherit from a
serializable
        class BaseManager, but if I'm reading this correctly, it looks like
the
        iBatis class StandardDaoManager is not serializable.  I can't edit
that
        class, of course.
        
        Here's what I want to know:
        
        1.  If I put the following code in my context.xml file, will it
prevent
        clustering from working properly?
        
        <Manager className="org.apache.catalina.session.PersistentManager"
        saveOnRestart="false" />
        
        
        2.  If the aforementioned context.xml snippet keeps clustering from
working,
        what options do I have to stop the warnings but keep clustering
working
        properly?
        
        
        Thanks for any insight!
        
        Jonathan
        

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