[hibernate-issues] [Hibernate-JIRA] Commented: (ANN-796) @Proxy annotation's reference documentation needs to improved

[Joonas Koivunen (JIRA)]

    [ http://opensource.atlassian.com/projects/hibernate/browse/ANN-796?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=32131#action_32131 ] 

Joonas Koivunen commented on ANN-796:
-------------------------------------

Another note that should be added is that all the interfaces described in the inheritance tree with @Proxy will be proxied by each and every object. 

A ClassCastException with bad message will be thrown if the object doesn't actually implement the interface. 

Could the ClassCastException message be modified to something more verbose than the actual class name of the proxied object is? It took a rather long time for me to figure from where the exception was thrown and why.

> @Proxy annotation's reference documentation needs to improved
> -------------------------------------------------------------
>
>                 Key: ANN-796
>                 URL: http://opensource.atlassian.com/projects/hibernate/browse/ANN-796
>             Project: Hibernate Annotations
>          Issue Type: Improvement
>          Components: documentation
>    Affects Versions: 3.4.0.GA
>         Environment: Core 3.3.1.GA, Apache Derby
>            Reporter: Joonas Koivunen
>   Original Estimate: 1 day
>  Remaining Estimate: 1 day
>
> I stumbled upon the problem documented for example here: http://www.hibernate.org/250.709.html, that you cannot just ask for the super-class and expect a child class' instance, even if for example toString() gives the correct answer.
> In http://www.hibernate.org/hib_docs/v3/reference/en/html/performance.html#performance-fetching-proxies the use of 
> <sub-class class="..." proxy="...">...</subclass>
> is documented. From that I realized that was this @Proxy annotation that I never thought of using before.
> Looking at http://www.hibernate.org/hib_docs/annotations/reference/en/html/entity.html#entity-hibspec that documents @Proxy:
> 1) It talks about proxyClassName attribute, which doesn't exist (any more at least), it has been replaced with Class<?> proxyClass
> 2) It doesn't mention anything about you having to annotate every class in the hierarchy from Cat to DomesticCat with @Proxy(proxyClass=BusinessInterfaceForEachClass.class)
> If not all of the hierarchy are annotated with @Proxy it'll throw a MappingException complaining that proxyClass is not an interface or the class itself, which doesn't quite translate to "you need to annotate whole hierarchy." Is this error because of some defaulting to void.class in the upper hierarchy perhaps?

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira