Hi Thiago, Thanks for the response - comments below.
>Tapestry-IoC create proxies around your service implementations, so, when >you @Inject UserEntityManager, the object your receive is proxy that >implements UserEntityManager, not BaseEntityManager. This means that the >proxy will invoke a method that returns IPersistentObject, not User. This is the nub of the problem - the proxy implements UserEntityManager, which by definition returns a User object for this particular method - not explicitly a IPersistentObject as in your example, though the returned object does implement IPersistentObject. I thought that the StackTrace might indicate that there is an exception in the ioc registry area that is not being caught / reported properly. If the java.lang.AbstractMethodError had a message that contained something indicating an unexpected return type / class cast issue etc. it would have been easier to pin down. >> This is to reduce the need for explicit casting around the application. >This doesn't seem right to me. You shouldn't rely on an specific >implementation of a given interface. If you need, why return an interface >in first place? Agreed - this is just for convenience in a very context relevant area of the system (user CRUD and other ops) - in other areas of the system the IPersistentObject interface is used as a matter of course in place of Users and other domain objects. Regards, Jim. -----Original Message----- From: Thiago H. de Paula Figueiredo [mailto:thiag...@gmail.com] Sent: 11 December 2009 12:39 To: Tapestry users Subject: Re: java.lang.AbstractMethodError - 5.1.0.5 Em Fri, 11 Dec 2009 10:23:11 -0200, Jim O'Callaghan <jc1000...@yahoo.co.uk> escreveu: > Hi, Hi! > I have a service bound to an interface in the ioc registry. The > interface extends another interface and duplicates a method name and > parameter list > however the return type in the overridden method is a concrete class > rather than an implementing interface, as specified in the super > interface ex.: Tapestry-IoC create proxies around your service implementations, so, when you @Inject UserEntityManager, the object your receive is proxy that implements UserEntityManager, not BaseEntityManager. This means that the proxy will invoke a method that returns IPersistentObject, not User. > This is to reduce the need for explicit casting around the application. This doesn't seem right to me. You shouldn't rely on an specific implementation of a given interface. If you need, why return an interface in first place? -- Thiago H. de Paula Figueiredo Independent Java, Apache Tapestry 5 and Hibernate consultant, developer, and instructor Owner, software architect and developer, Ars Machina Tecnologia da Informação Ltda. http://www.arsmachina.com.br --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tapestry.apache.org For additional commands, e-mail: users-h...@tapestry.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tapestry.apache.org For additional commands, e-mail: users-h...@tapestry.apache.org
