Atleast one role of a foreign-key mapped relationship must h

[jhenschel]

Hi all,

I seem to have a stupid problem modeling a many-to-one relationship between 2 tables:

one FELD(ID, ...) has many TEST(ID, ..., FELDID, ...)

I created ejb-jar.xml and jbosscmp-jdbc.xml according to the DTDs and JBoss docs (I'm using JBoss 3.2.2 with Oracle8i).

Yet, when I deploy the resuzlting ejb.jar file, JBoss throws me the below exception. I'm quite puzzled why this happens, especially since both of my <ejb-relationship-role> elements in jbosscmp-jdbc.xml define a <key-fields> element.

Below are the relevant snippets from both deployment descriptors, does anyone have a clue why the Exception gets thrown and how to fix it?

Thanks in advance,
Joerg Henschel


Exception thown by JBoss during deployment:
-----------------------------------------------------------------

... <snip/> ...
16:10:57,094 INFO [EjbModule] Deploying Feld
16:10:57,104 INFO [EjbModule] Deploying Test
16:10:57,805 ERROR [EntityContainer] Starting failed
org.jboss.deployment.DeploymentException: Atleast one role of a foreign-key mapped relationship must have key fields (or <pri
mkey-field> is missing from ejb-jar.xml): ejb-relation-name=FELD-TEST
 at org.jboss.ejb.plugins.cmp.jdbc.metadata.JDBCRelationMetaData.<init>(JDBCRelationMetaData.java:347)
 at org.jboss.ejb.plugins.cmp.jdbc.metadata.JDBCApplicationMetaData.<init>(JDBCApplicationMetaData.java:412)
 at org.jboss.ejb.plugins.cmp.jdbc.metadata.JDBCXmlFileLoader.load(JDBCXmlFileLoader.java:67)
 at org.jboss.ejb.plugins.cmp.jdbc.JDBCStoreManager.loadJDBCEntityMetaData(JDBCStoreManager.java:676)
 at org.jboss.ejb.plugins.cmp.jdbc.JDBCStoreManager.initStoreManager(JDBCStoreManager.java:372)
 at org.jboss.ejb.plugins.cmp.jdbc.JDBCStoreManager.start(JDBCStoreManager.java:320)
 at org.jboss.ejb.plugins.CMPPersistenceManager.start(CMPPersistenceManager.java:152)
 at org.jboss.ejb.EntityContainer.startService(EntityContainer.java:343)
... <snip/> ...

-----------------------------------------------------------------

ejb-jar.xml
-----------------------------------------------------------------

<relationships>
 <ejb-relation >
 <ejb-relation-name>
 FELD-TEST
 </ejb-relation-name>
 <ejb-relationship-role >
 <ejb-relationship-role-name>
 FELD-has-TESTs
 </ejb-relationship-role-name>
 <multiplicity>
 One
 </multiplicity>
 <relationship-role-source >
 <ejb-name>
 Feld
 </ejb-name>
 </relationship-role-source>
 <cmr-field >
 <cmr-field-name>
 tests
 </cmr-field-name>
 <cmr-field-type>
 java.util.Collection
 </cmr-field-type>
 </cmr-field>
 </ejb-relationship-role>
 <ejb-relationship-role>
 <ejb-relationship-role-name>
 TEST-belongsTo-FELD
 </ejb-relationship-role-name>
 <multiplicity>
 Many
 </multiplicity>
 <relationship-role-source>
 <ejb-name>
 Test
 </ejb-name>
 </relationship-role-source>
 <cmr-field >
 <cmr-field-name>
 feld
 </cmr-field-name>
 </cmr-field>
 </ejb-relationship-role>
 </ejb-relation>
 </relationships>

jbosscmp-jdbc.xml
------------------------------------------------------

<relationships>
 <ejb-relation>
 <ejb-relation-name>
 FELD-TEST
 </ejb-relation-name>
 <foreign-key-mapping/>
 <ejb-relationship-role>
 <ejb-relationship-role-name>
 FELD-has-TESTs
 </ejb-relationship-role-name>
 <key-fields>
 <key-field>
 <field-name>
 id
 </field-name>
 <column-name>
 FELDID
 </column-name>
 </key-field>
 </key-fields>
 </ejb-relationship-role>
 <ejb-relationship-role>
 <ejb-relationship-role-name>
 TEST-belogsTo-FELD
 </ejb-relationship-role-name>
 <key-fields/>
 </ejb-relationship-role>
 </ejb-relation>
 </relationships>

[jhenschel]

After a day of debugging I found the cause of the error:

It seems that JBoss throws this Exception if one or both of the PrimaryKey - classes participating in the relationship has no constructors. Of course PK classes should come with constructors all the time, so I only have myself to blame.

Still, the error message made me suspect the DD's even they were just fine.