500 A CMR collection may only be used within the transction

[ahjulsta]

What does this really mean?

HTTP ERROR: 500 A CMR collection may only be used within the transction in which it was created

I have several servlets and jsp pages all accessing local interfaces on my entity beans. The "ncontext" object is stored in the session.

// Get the "sig" object. This method will lazily
// create an entity bean, and keep a reference to the
// local interface.
Signatur sig = ncontext.getSignatur();
// This method navigates a one-to-many CMR relation
Collection bevegelser = sig.getBevegelsesPoster();

After this, if I do
bevegelser.isEmpty() or bevegelser.iterator() in the same jsp, I get the error message above.

(Stacktrace)
org.jboss.ejb.plugins.cmp.jdbc.bridge.RelationSet.getIdList(RelationSet.java:53)
org.jboss.ejb.plugins.cmp.jdbc.bridge.RelationSet.isEmpty(RelationSet.java:64)
(the rest is my jsp and prior calls)

Aren't I supposed to be able to do this? I thought part of the concept behind local interfaces was that one could navigate cmr's from jsp's / servlets.

Any ideas as to what might be wrong?

Åsmund Hjulstad

[ahjulsta]

Sorry, should have read the spec more carefully.

This solves the problem:

UserTransaction trans = new InitialContext().lookup("java:comp/UserTransaction");

trans.begin();
// do stuff
trans.commit();

Being spoiled with CMT when writing beans dulls my brain.. :-)

However, one problem still remains:
I use a MVC pattern, with a JSP view, servlet controller, and EJB Local-objects as the model. After having made changes to the data in the controller (servlet), and redirecting to the jsp page, the changes are not visible yet. A reload (1/2 sec afterwards) gives me the desired data.

What can be done to fix this?

(And BTW, when experiencing the previous problem, the response was not consistent. Sometimes it could work; after some irrelevant code changes (outputting more html), it wouldn't. Could this indicate that there is a timing issue of some sort related to the transaction manager? I'm using CVS as of January 18th, just before Marc Fleury started committing the UnifiedDeployer.. )

[ardochoke]

I have an application that worked in JBoss 3.0.0 and I moved to 3.0.2 to try and fix an unrelated problem.

Now my existing code is giving me the following error:
java.lang.IllegalStateException: A CMR collection may only be used within the transction in which it was created

I have two CMP Entity Beans (User and Roles). These are connected with a Many to Many relationship.

My ejb-relationship looks like:

<ejb-relation>
<ejb-relation-name>User-Role</ejb-relation-name>
<ejb-relationship-role>
<ejb-relationship-role-name>user-has-roles</ejb-relationship-role-name>
Many

<relationship-role-source>
<ejb-name>UserEJB</ejb-name>
</relationship-role-source>

<cmr-field>
<cmr-field-name>roles</cmr-field-name>
<cmr-field-type>java.util.Collection</cmr-field-type>
</cmr-field>
</ejb-relationship-role>

<ejb-relationship-role>
<ejb-relationship-role-name>role-has-users</ejb-relationship-role-name>
Many

<relationship-role-source>
<ejb-name>RolesEJB</ejb-name>
</relationship-role-source>

<cmr-field>
<cmr-field-name>users</cmr-field-name>
<cmr-field-type>java.util.Collection</cmr-field-type>
</cmr-field>
</ejb-relationship-role>
</ejb-relation>


In all the CMP examples I have looked at no one seems to play with the transactions directly - which seems to be what this thread is suggesting? I have both EJB's in <container-transaction> section and <trans-attribute> set to Required.

The code snippet is:

// OK
UserLocalHome myUserHome = getUserLocalHome();
UserLocal myUser = myUserHome.findByPrimaryKey(username);

// OK
RolesLocalHome myRoleHome = getRolesLocalHome();
RolesLocal myRole = myRoleHome.findByName(roleName);

// Exception thrown on this line
if( myUser.getRoles().contains(myRole) ) {


I have spent many hours searching forums, etc. but I wouldn't be suprised if I'm just doing something stupid...

Any advice would be greatly appreciated.

Regards,
Adrian

[dsundstrom]

The code needs to be wrapped in a transaction using either a UserTransaction or a SessionBean.