jackrabbit-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Stefan Guggisberg <stefan.guggisb...@gmail.com>
Subject Re: Item cannot be saved because it has been modified externally: node /
Date Mon, 13 Dec 2010 09:33:07 GMT
On Sat, Dec 11, 2010 at 11:52 AM, Norman Maurer <norman@apache.org> wrote:
> Hi there,
>
> this is fixed in the upcomming jackrabbit 2.2.0 (which should be
> released within the next days). In the meantime you can grab a
> snapshot here:
>
> https://repository.apache.org/content/groups/snapshots/org/apache/jackrabbit/
>
> Version name is 2.2-SNAPSHOT.

sorry, but i have to contradict norman.

the following behavior is as per design:

1. sessionA modifies a property
2. sessionB modifies the same property and saves its changes
3. sessionA tries to save its changes but fails with a
   InvalidItemStateException because its changes have become stale

this is the behavior as implemented in trunk.

cheers
stefan

>
> Bye,
> Norman
>
>
>
>
> 2010/12/11 François Cassistat <f@maya-systems.com>:
>> I've managed to make some basic case that throws the error every time.
>>
>> import org.apache.jackrabbit.core.TransientRepository;
>>
>> import javax.jcr.*;
>>
>> public class JCRConcurrency
>> {
>>    public static void main(String[] args) throws RepositoryException
>>    {
>>        Repository repo;
>>        if (args.length >= 2)
>>            repo = new TransientRepository(args[0], args[1]);
>>        else
>>            repo = new TransientRepository();
>>        SimpleCredentials simpleCredentials = new SimpleCredentials("username",
"password".toCharArray());
>>        Session sessionInit = repo.login(simpleCredentials);
>>
>>        // initialization
>>        Node root = sessionInit.getRootNode();
>>        Node test;
>>        if (root.hasNode("test"))
>>            test = root.getNode("test");
>>        else
>>            test = root.addNode("test");
>>        if (!test.hasProperty("property"))
>>            test.setProperty("property", 0);
>>        sessionInit.save();
>>        String testIdentifier = test.getIdentifier();
>>
>>        // session 1
>>        Session session1 = repo.login(simpleCredentials);
>>        Node test1 = session1.getNodeByIdentifier(testIdentifier);
>>        System.out.println(test1.getProperty("property").getLong());
>>        test1.setProperty("property", 1);
>>
>>        // session 2 is doing some other things at the same time
>>        Session session2 = repo.login(simpleCredentials);
>>        Node test2 = session2.getNodeByIdentifier(testIdentifier);
>>        test2.setProperty("property", 2);
>>
>>        // session 2 saves first
>>        session2.save();
>>        session2.logout();
>>
>>        // session 1 saves
>>        session1.save();
>>        session1.logout();
>>
>>        sessionInit.logout();
>>
>>        System.exit(0);
>>    }
>> }
>>
>>
>>
>>
>> Le 2010-12-10 à 6:12 PM, François Cassistat a écrit :
>>
>>> Hi list !
>>>
>>> I've got some concurrency problem while saving. My application use distinct Sessions
object and when two processes are trying to modify the same property of the same node at the
same time. I've get the exception below :
>>> javax.jcr.InvalidItemStateException: Item cannot be saved because it has been
modified externally: node /
>>>        at org.apache.jackrabbit.core.ItemImpl.getTransientStates(ItemImpl.java:249)
>>>        at org.apache.jackrabbit.core.ItemImpl.save(ItemImpl.java:981)
>>>        at org.apache.jackrabbit.core.SessionImpl.save(SessionImpl.java:920)
>>>        at com.myproject.MyProject.save(MyProject.java:1525)
>>>        ...
>>>
>>>
>>> I have tried saving this way :
>>> synchronized (this)
>>> {
>>>    session.refresh(true);
>>>    session.save();
>>> }
>>>
>>>
>>> Is there any way around or only locks and transactions can prevent that ?
>>>
>>>
>>> Thanks !
>>>
>>>
>>> François
>>>
>>
>>
>

Mime
View raw message