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<td class="text-paragraph-pattern-container mobile-resize-text " style="padding: 0; border-collapse: collapse; padding: 0 0 10px"> <p style="margin: 10px 0 0; margin-top: 0">Thanks for taking the time to reply and offer suggestions.</p> <p style="margin: 10px 0 0">The warning would simply be helpful to let me know that the eventual ClassCastException is due to my usage pattern, not my mapping.</p> <p style="margin: 10px 0 0">I understand that it's ideal for getReference to not run a query. Ordinarily it's not an issue, however with @Inheritance there are some subtle problems.</p> <p style="margin: 10px 0 0">The current situation causes a difficult-to-understand <tt>ClassCastException</tt>, which may lead some developers (read: me) to suspect a problem with their <tt>@Inheritance</tt> scheme when, in fact, it's a problem with the pattern of usage ... it's just not immediately obvious from the place in code where the error occurs, since the <tt>getReference()</tt> may have been called long before the <tt>find()</tt> where the error eventually shows up.</p> <p style="margin: 10px 0 0">Just recapping the potential solutions that come to mind (maybe adding one or two):</p>
<ol>
<li>Have <tt>getReference()</tt> make a minimal query when an entity is marked with <tt>@Inheritance</tt> – <em>not ideal since we'd like to avoid a query</em></li>
<li>Have <tt>find()</tt>, which ordinarily would make a DB call,determine that it's about to return a proxy of the wrong type and emit a warning – <em>may be complicated to implement?</em></li>
<li>Have getReference() emit a warning in the case it's returns an Entity marked with <tt>@Inheritance</tt> – <em>not ideal, since we'd be warned about cases where we don't care about the type.</em></li>
<li>Do #1 only optionally according to some setting – <em>this would only help people who know about the setting</em></li>
<li>Find a way to dynamically change the runtime interfaces implemented by the proxy – <em>this may not be possible, I haven't found a way to do it but don't have a lot of experience with manipulating proxies</em></li>
<li>In the case of an Entity with <tt>@Inheritance</tt> where a proxy is already in the session, have <tt>find()</tt> create a new proxy, proxying the original proxy, but with a correct type – <em>this may violate the JPA spec</em></li>
</ol> <p style="margin: 10px 0 0">Maybe some others on the Hibernate dev team may have thoughts on the subject?</p> <p style="margin: 10px 0 0">For now, I'll do my best to avoid using <tt>getReference()</tt> on entities with <tt>@Inheritance</tt> and I have asked the people I work with to do the same.</p> </td>
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