getSingleResult returns proxy on native scalar query in hibernate

Question

I'm working on switching my JPA persistence provider from EclipseLink 2.3 to Hibernate 3.6.5.Final. The problem is with a native query. Note: this wasn't a problem with EclipseLink. I'm trying to obtain a scalar value, a String from a table that I don't have an Entity declared for. Here is the code:

Query q = em.createNativeQuery("select description from foo where foo_id = ?");
q.setParameter(1, fooId);
String description = (String)q.getSingleResult();

With Hibernate I get a ClassCastException because the object returned is actually a proxy object. I don't know what type it is, but I know it isn't an array (object.getClass().isArray() is false) and I know it isn't a List (object instanceof List is false).

What am I missing?

Answer 1

Summarizing comments below the question:

What interfaces does q.getSingleResult().getClass().getInterfaces() return?

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It is of type java.sql.Clob, org.hibernate.engine.jdbc.WrappedClob, and java.io.Serializable. [...] I didn't even realize the column was a clob and I'm surprised EclipseLink was doing the conversion to String for me

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Looks like EclipseLink is smart enough to convert CLOB (which is actually a very long sequence of characters, just like String) to String if required. With Hibernate this must be done explicitly. I guess this complies to the JPA specification.