RE: Cayenne -- Apache automatic deploy problem

From: Marc Gabriel-Willem (marc.gabriel-wille..ide-international.com)
Date: Thu Apr 05 2007 - 10:37:36 EDT

  • Next message: Mike Kienenberger: "Re: Cayenne -- Apache automatic deploy problem"

    Hello,

    Are you handling DataContext in that way because you experienced the
    same problem than me? I've the feeling the problem I've detected is a
    bug that should be address, isn't it ?

    Marc

    -----Original Message-----
    From: Mike Kienenberger [mailto:mkienen..mail.com]
    Sent: Tuesday, April 03, 2007 6:39 PM
    To: use..ayenne.apache.org
    Subject: Re: Cayenne -- Apache automatic deploy problem

    DataContext is serializable. I serialize the read-only one in a
    session.
    However, I don't want to serialize the entire modifiable context and
    everything it contains as client-side state. I only want to write
    out specific objects for performance reasons.

    When you serialize a DataObject without a DataContext, it's your
    responsibility to reconnect your DataObject back to a DataContext.

    On 4/3/07, Marc Gabriel-Willem
    <marc.gabriel-wille..ide-international.com> wrote:
    > What your 'workaround' mean? Are you facing serialization /
    > deserialization problem with application server and cayenne? Have you
    > got some hasardous behavior?
    > Normally, cayenne context should be 'serializable compliant', so if it
    > is not, it should be addressed isn't it?
    >
    > -----Original Message-----
    > From: Mike Kienenberger [mailto:mkienen..mail.com]
    > Sent: Monday, April 02, 2007 4:32 PM
    > To: use..ayenne.apache.org
    > Subject: Re: Cayenne -- Apache automatic deploy problem
    >
    > I've used Cayenne in a couple of JSF applications.
    >
    > Up to this point, my best solution was to use a servlet filter to save
    > and restore the primary DataContext in the session. This is a
    > read-only (or write-request-only) context, and I explicitly check at
    > the end of every request to insure it's in a non-dirty state. Thus,
    > if necessary, I can create a completely-new DataContext on the next
    > request -- storing this DataContext in the session is simply a
    > performance enhancer.
    >
    > I then also have a set of modified DataObjects in a temporary
    > DataContext that I saveState into the client-side save state. I
    > don't save the DataContext; I only save the objects.
    >
    > My DataObject superclass has these serialization methods. There's a
    > lot of extra logging in here from when I was debugging it -- not every
    > path is taken.
    >
    >
    > ////// Serialization
    >
    > private void writeObject(java.io.ObjectOutputStream out)
    > throws IOException
    > {
    > Logger logger = Logger.getLogger("serialization");
    > if (null == this.getDataContext())
    > {
    > logger.info("writeObject: " +
    this.getClass().getName()
    > + "
    > [" + String.valueOf(this.hashCode()) + "] has no DC.");
    > logger.info("writeObject: " + this);
    > Thread.dumpStack();
    > }
    > out.writeBoolean(Boolean.TRUE ==
    > this.getDataContext().getUserProperty("temporary"));
    > out.defaultWriteObject();
    >
    > if (Boolean.TRUE ==
    > this.getDataContext().getUserProperty("temporary"))
    > {
    > logger.info("writeObject: " +
    this.getClass().getName()
    > + "
    > [" + String.valueOf(this.hashCode()) + "] has DC [" +
    > String.valueOf(this.getDataContext().hashCode()) + "] and is marked
    > temporary.");
    > }
    > else
    > {
    > logger.info("writeObject: " +
    this.getClass().getName()
    > + "
    > [" + String.valueOf(this.hashCode()) + "] has DC [" +
    > String.valueOf(this.getDataContext().hashCode()) + "] and is not
    > marked temporary.");
    > }
    > }
    >
    > private void readObject(java.io.ObjectInputStream in)
    > throws IOException, ClassNotFoundException
    > {
    > boolean isInTemporaryDataContext = in.readBoolean();
    > in.defaultReadObject();
    > this.isInTemporaryDataContext = isInTemporaryDataContext;
    >
    > Logger logger = Logger.getLogger("serialization");
    > if (null != this.getDataContext())
    > {
    > if (isInTemporaryDataContext)
    > {
    > logger.info("readObject: " + this.getClass().getName()
    +
    > " [" + String.valueOf(this.hashCode()) + "] has DC [" +
    > String.valueOf(this.getDataContext().hashCode()) + "] and is marked
    > temporary.");
    > }
    > else
    > {
    > logger.info("readObject: " + this.getClass().getName()
    +
    > " [" + String.valueOf(this.hashCode()) + "] has DC [" +
    > String.valueOf(this.getDataContext().hashCode()) + "] and is not
    > marked temporary.");
    > }
    > }
    > else
    > {
    > if (isInTemporaryDataContext)
    > {
    > logger.info("readObject: " + this.getClass().getName()
    +
    > " [" + String.valueOf(this.hashCode()) + "] has no DC and is marked
    > temporary.");
    > }
    > else
    > {
    > logger.info("readObject: " + this.getClass().getName()
    +
    > " [" + String.valueOf(this.hashCode()) + "] has no DC and is not
    > marked temporary.");
    > }
    > }
    > }
    > /**
    > * Substitute self with an object registered in thread
    > * DataContext with the same ID.
    > */
    > protected Object readResolve() throws ObjectStreamException
    > {
    > if (null == getDataContext())
    > {
    > if (isInTemporaryDataContext)
    > {
    > Logger logger = Logger.getLogger("serialization");
    > logger.info("readResolve: " +
    this.getClass().getName()
    > +
    > " [" + String.valueOf(this.hashCode()) + "] has no DC and is marked
    > temporary.");
    >
    > return this;
    > }
    > else
    > {
    > Logger logger = Logger.getLogger("serialization");
    > logger.info("readResolve: " +
    this.getClass().getName()
    > +
    > " [" + String.valueOf(this.hashCode()) + "] has no DC and is not
    > marked temporary.");
    >
    > DataContext context;
    >
    > try {
    > context = DataContext.getThreadDataContext();
    > }
    > catch (IllegalStateException e) {
    > throw new NotActiveException("Can't deserialize
    > object for id '"
    > + getObjectId()
    > + "' - no DataContext bound to thread.");
    > }
    >
    > // return context.registeredObject(getObjectId());
    > return context.localObject(getObjectId(), null);
    > }
    > }
    > else
    > {
    > Logger logger = Logger.getLogger("serialization");
    > logger.info("readResolve: " +
    this.getClass().getName()
    > + "
    > [" + String.valueOf(this.hashCode()) + "] has DC [" +
    > String.valueOf(this.getDataContext().hashCode()) + "].");
    > return this;
    > }
    > }
    >
    >
    >
    >
    >
    > On 4/2/07, Marc Gabriel-Willem
    > <marc.gabriel-wille..ide-international.com> wrote:
    > > Yes, it seems to have a problem with the 'awakeFromDeserialization'
    > > function. Not sure to understand what you mean by 'code called
    before
    > > cayenne is loaded' but for your information the code that crash is
    > > called by a jsf action method.
    > >
    > > Moreover, the problem seems to come from 'relationship objects' (in
    my
    > > case: m_editableGroup.getGroupContentArray()).
    > >
    > > To summarize:
    > >
    > > 1) In a backing bean, I create a child data context and store it as
    a
    > > member variable.
    > > 2) I link entity objects to that child data context.
    > > 3) I modify those entity objects
    > > 4) I shut down the tomcat server
    > > 5) I restart the the tomcat server
    > > 6) I call a jsf action method (in my business, a save) and then the
    > > crash appear :|
    > >
    > > Thank you for your help.
    > >
    > > Marc
    > >
    > > -----Original Message-----
    > > From: Andrus Adamchik [mailto:andru..bjectstyle.org]
    > > Sent: Sunday, April 01, 2007 3:25 PM
    > > To: use..ayenne.apache.org
    > > Subject: Re: Cayenne -- Apache automatic deploy problem
    > >
    > > This likely means that 'awakeFromDeserialization' [1] failed to
    > > attach DataContext to Cayenne stack. Is it possible that the code in
    > > question called before Cayenne stack is loaded? Where is it called
    > > anyways?
    > >
    > > Andrus
    > >
    > >
    > > [1]
    http://svn.apache.org/repos/asf/cayenne/main/branches/STABLE-2.0/
    > > cayenne/cayenne-java/src/cayenne/java/org/apache/cayenne/access/
    > > DataContext.java
    > >
    > > On Mar 30, 2007, at 10:55 AM, Marc Gabriel-Willem wrote:
    > >
    > > > Hello,
    > > >
    > > > I checked the entity resolver value.
    > > > Indeed, in this situation the value is 'null'.
    > > >
    > > > Marc
    > > >
    > > > -----Original Message-----
    > > > From: Andrus Adamchik [mailto:andru..bjectstyle.org]
    > > > Sent: Friday, March 30, 2007 4:16 PM
    > > > To: use..ayenne.apache.org
    > > > Subject: Re: Cayenne -- Apache automatic deploy problem
    > > >
    > > > I can't reproduce this error in a test case. I am out of ideas
    what
    > > > might have caused it. Can you possibly debug this condition to
    > figure
    > > > out why the 'metadata' field in DataContextQueryAction is null?
    > First
    > > > thing to check:
    > > >
    > > > m_editableGroup.getObjectContext().getEntityResolver() != null
    > > >
    > > >
    > > > Andrus
    > > >
    > > >
    > > > On Mar 30, 2007, at 5:24 PM, Marc Gabriel-Willem wrote:
    > > >
    > > >> Hello,
    > > >>
    > > >> Sorry, it is the first time I'm using a list like this one. So,
    I'm
    > > >> doing some crazy error with it :) For example, I hope my "reply
    > > >> all" is
    > > >> a correct action to do in this case.
    > > >>
    > > >> I saw your first reply.
    > > >>
    > > >> I have exactly the same error when I stop and restart properly
    the
    > > >> Tomcat server. In fact, stoping and restarting the server
    simulate
    > > >> the
    > > >> serialization / deserialization operation that an application
    > > >> server can
    > > >> do at any time it wants (isn't it ?)
    > > >>
    > > >> Marc
    > > >>
    > > >> -----Original Message-----
    > > >> From: Andrus Adamchik [mailto:andru..bjectstyle.org]
    > > >> Sent: Friday, March 30, 2007 3:09 PM
    > > >> To: use..ayenne.apache.org
    > > >> Cc: Marc Gabriel-Willem
    > > >> Subject: Re: Cayenne -- Apache automatic deploy problem
    > > >>
    > > >> Hi, See my original reply asking for more information here:
    > > >>
    > > >>
    http://objectstyle.org/cayenne/lists/cayenne-user/2007/03/0101.html
    > > >>
    > > >> BTW, it would be much easier to communicate if you subscribe to
    the
    > > >> list :-)
    > > >>
    > > >> Andrus
    > > >>
    > > >>
    > > >> On Mar 30, 2007, at 4:46 PM, Marc Gabriel-Willem wrote:
    > > >>
    > > >>> Hi,
    > > >>>
    > > >>>
    > > >>>
    > > >>> Sorry to repost that question, but I was not properly register
    to
    > > >>> the
    > > >>> mailing list, so I was unable to reply properly.
    > > >>>
    > > >>>
    > > >>>
    > > >>> I'm using Cayenne (2.0.2) with the apache web server (5.5.20)
    and
    > > >>> I'm
    > > >>> facing to the following problem.
    > > >>>
    > > >>>
    > > >>>
    > > >>> When apache does an automatic deploy, all objects are serialized
    /
    > > >>> deserialized without any error.
    > > >>>
    > > >>> But after that, when the code accesses a cayenne persistent
    object
    > > >>> (member variable of a jsf backing bean), the following problem
    > > >>> occurs:
    > > >>>
    > > >>>
    > > >>>
    > > >>> Caused by: java.lang.NullPointerException
    > > >>>
    > > >>> at
    > > >>>
    > org.apache.cayenne.access.DataContextQueryAction.interceptPaginatedQ
    > >
    > > >>> u
    > > >
    > > >>> e
    > > >>
    > > >>> ry
    > > >>> (DataContextQueryAction.java:91)
    > > >>>
    > > >>> at
    > > >>> org.apache.cayenne.access.DataContextQueryAction.execute
    > > >>> (DataContextQuer
    > > >>> yAction.java:50)
    > > >>>
    > > >>> at
    > > >>>
    > org.apache.cayenne.access.DataContext.onQuery(DataContext.java:1387)
    > > >>>
    > > >>> at
    > > >>>
    > org.apache.cayenne.access.DataContext.performQuery(DataContext.java:
    > > >>> 1376
    > > >>> )
    > > >>>
    > > >>> at
    > > >>> org.apache.cayenne.access.ToManyList.resolvedObjectList
    > > >>> (ToManyList.java:
    > > >>> 307)
    > > >>>
    > > >>> at
    > > >>> org.apache.cayenne.access.ToManyList.size(ToManyList.java:260)
    > > >>>
    > > >>> at
    > > >>> com.sideinternational.web.profiling.group.GroupEditor.save
    > > >>> (GroupEditor.j
    > > >>> ava:246)
    > > >>>
    > > >>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native
    > > >>> Method)
    > > >>>
    > > >>> at
    > > >>> sun.reflect.NativeMethodAccessorImpl.invoke
    > > >>> (NativeMethodAccessorImpl.jav
    > > >>> a:39)
    > > >>>
    > > >>> at
    > > >>> sun.reflect.DelegatingMethodAccessorImpl.invoke
    > > >>> (DelegatingMethodAccessor
    > > >>> Impl.java:25)
    > > >>>
    > > >>> at java.lang.reflect.Method.invoke(Method.java:585)
    > > >>>
    > > >>> at
    > > >>> org.apache.myfaces.el.MethodBindingImpl.invoke
    > > >>> (MethodBindingImpl.java:13
    > > >>> 2)
    > > >>>
    > > >>>
    > > >>>
    > > >>> For information, the following code throws that exception (the
    > > >>> call to
    > > >>> the size() method) :
    > > >>>
    > > >>> List itemsToRemove = m_editableGroup.getGroupContentArray();
    > > >>>
    > > >>> for (int i=0; i < itemsToRemove.size(); i)
    > > >>>
    > > >>> ...
    > > >>>
    > > >>> Note: Child data context and ObjectEntities are stored in a
    > > >>> serializable
    > > >>> jsf backing bean.
    > > >>>
    > > >>>
    > > >>>
    > > >>> Thank you for your help.
    > > >>>
    > > >>>
    > > >>>
    > > >>> Marc Gabriel
    > > >>>
    > > >>>
    > > >>>
    > > >>>
    > > >>>
    > > >>
    > > >>
    > > >>
    > > >
    > > >
    > > >
    > >
    > >
    > >
    >
    >



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