[
https://issues.apache.org/jira/browse/OPENJPA-1804?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12912482#action_12912482
]
Willis Blackburn commented on OPENJPA-1804:
-------------------------------------------
The <class> section looks like:
com.signetworks.signs.model.addressbook.AddressBook
com.signetworks.signs.model.security.Group
com.signetworks.signs.model.security.Organization
com.signetworks.signs.model.security.User
I've discovered some more information that is relevant. The Organization
object contains a Set<HostName>. HostName is an Embeddable. However:
1. HostName is obviously not in the list of persistent classes.
2. When I looked in the class file for Organization, I discovered that the set
of host names did not have any generic type information. In other words it was
Set<?> instead of Set<HostName>. That's why OpenJPA complains (above) about
"No metadata was found for type 'class java.lang.Object.'" (The reason that
the generic type information is missing is that this project is in Scala, and
the Set<HostName> is defined in a Scala trait that the Organization class
inherits, and apparently Scala discards generic type information when compiling
classes that inherit members from traits.)
I discovered these two issues by running the standalone enhancer on my
classfiles. The standalone enhancer doesn't produce NullPointerException, at
least not in my tests, but does complain about Object not being a persistent
classes. Once I fixed the two issues, then the runtime enhancer started
working as well.
I still think that this is a bug, as OpenJPA should not generate NPE even if
the input mapping has errors.
> NPE in MappingInfo.java line 1514
> ---------------------------------
>
> Key: OPENJPA-1804
> URL: https://issues.apache.org/jira/browse/OPENJPA-1804
> Project: OpenJPA
> Issue Type: Bug
> Components: Enhance
> Affects Versions: 2.0.1
> Reporter: Willis Blackburn
>
> I am encountering a NPE at MappingInfo.java line 1514. I'm sorry I don't
> have time to prepare a test case right now. I'm not even 100% sure what is
> causing the problem, but it seems to be something like this:
> I have classes Organization, Group, User, and AddressBook.
> Group has a reference (many-to-one) to Organization.
> I'm using field-level access and the Java 6 runtime enhancer. (NOT the
> build-time enhancer or the agent.)
> In ManagedClassSubclasser.prepareUnenhancedClasses, the code receives a list
> of Class objects--the ones in persistence.xml. They are not in the same
> order as they are in persistence.xml, but I don't know if that's important.
> The first one is Group. During the processing of Group, the code invokes
> ClassMapping.setTable to set the table name, which is "group_table." This
> comes from the @Table annotation of Group. So far, so good. Then the code
> does some additional processing on the relationship mappings of Group, which
> include the reference to Organization. During the processing of that
> relationship, the code calls MappingInfo.mergeJoinColumn. On line 1367, the
> method calls rel.getTable. The "rel" variable points to the ClassMapping for
> Organization. Remember that prepareUnenhancedClasses hasn't gotten to
> Organization yet--it's still working on Group--and so I assume that this
> Organization mapping was created on-demand. However, rel.getTable returns
> null. The Organization class has a @Table attribute, and I can see that the
> table name has been loaded in the ClassMappingInfo instance attached to the
> ClassMapping for Organization, however the table name has not yet been copied
> from ClassMappingInfo to ClassMapping. Later, the mergeJoinColumn method
> attempts to dereference the null table name and generates the NPE.
> Bottom line: When using the Java 6, runtime enhancer, if class A has a
> reference to class B, and both classes have @Table annotations (at least),
> and class A is processed first, then it produces a NPE.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
