[OPENJPA-147] <T> T OpenJPAEntityManager.createInstance(Class<T> cls) fails when T is interface

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.1.0
• Component/s: jpa
• Assignee: Unassigned
• Reporter: Pinaki Poddar
• Created: 14/Feb/07 18:17
• Updated: 09/Mar/10 18:32
• Resolved: 15/Jan/08 21:51

Description

According to JavaDoc, OpenJPAEntityManager.createInstance() method
public <T> T createInstance(Class<T> cls);
behaves as follows:

"Create a new instance of type <code>cls</code>. If <code>cls</code> is
an interface or an abstract class whose abstract methods follow the
JavaBeans convention, this method will create a concrete implementation
according to the metadata that defines the class"

The method fails when T is an interface. The failure may be due to incorrect user configuration, however, further
information on this extension method is not available in OpenJPA documentation.

Firstly, how to specify metadata for a interface that has bean-style methods?
Possibilities are:
a) Annotating the Java interface definition with @Entity
b) Specifying in <class>org.acme.IPerson</class> in persistence.xml

Either of the above fails. a) fails at parsing b) fails with "no metadata"

There may be a correct but undocumented way of specifying a managed interface. If that is the case, then this JIRA report should be treated as a documentation bug.

Issue Links

• is cloned by: OPENJPA-486 OpenJPAEntityManager.createInstance(Class<T> cls) fails when T is an abstract class
• is related to: OPENJPA-481 Queries against managed interfaces do not work in "mixed interface" configuration