Comments on: Working with Java 5 Annotations http://www.basilv.com/psd/blog/2008/working-with-java-5-annotations Wed, 08 Feb 2012 03:57:22 +0000 hourly 1 http://wordpress.org/?v=3.3 By: Basil Vandegriend http://www.basilv.com/psd/blog/2008/working-with-java-5-annotations/comment-page-1#comment-105027 Basil Vandegriend Fri, 05 Mar 2010 03:21:28 +0000 http://www.basilv.com/psd/blog/2008/working-with-java-5-annotations#comment-105027 I'm not sure I follow what you are trying to accomplish. With respect to overriding annotations with XML in Java EE, this is done by a container (Spring context, Hibernate session factory, EJB container, etc.) that populates an internal configuration/metadata structure based on defaults, then revises it based on information provided in annotations and separate XML configuration files. The key is the central container to manager this process. While I'm not sure exactly how you are trying to override annotations, using the same approach of a container responsible for populating an internal data structure is a good pattern to follow. I’m not sure I follow what you are trying to accomplish. With respect to overriding annotations with XML in Java EE, this is done by a container (Spring context, Hibernate session factory, EJB container, etc.) that populates an internal configuration/metadata structure based on defaults, then revises it based on information provided in annotations and separate XML configuration files. The key is the central container to manager this process. While I’m not sure exactly how you are trying to override annotations, using the same approach of a container responsible for populating an internal data structure is a good pattern to follow.

]]> By: Cor http://www.basilv.com/psd/blog/2008/working-with-java-5-annotations/comment-page-1#comment-105000 Cor Thu, 04 Mar 2010 09:25:56 +0000 http://www.basilv.com/psd/blog/2008/working-with-java-5-annotations#comment-105000 What I am curious about is the following: There is a mechanism to override the annotated values, in the J2EE world the annotated values are overridden by the XMLs at runtime, presumably to prevent inserting production values in a development environment -which may not be known at development time. But which ever way I try, I cannot come up with a mechanism which allows for an override of the values while working with the annotations as an interface. I have not been able to find a setting mechanism which allows me to override a value with another (which might be retrieved from file). Likewise I have not been able to find a mechanism to add an annotation at runtime. This then leaves me to write implementations for the interfaces (which are no real interfaces) representing the annotations. That however is disencouraged by my compiler/IDE telling me that annotations should not be used as an interface. As a consequence I would be forced to write another interface or container class receiving the information from the annotations and/or the overriding file, but in my view that should be not necessary as the interface is already present (i.e. the annotation). And defining a interface extending the annotation interface is disencouraged as well. So I am almost forced to duplicate the information from the annotation interface, which is against all views regarding re-use in OO. What is your view/advice on this? What I am curious about is the following:
There is a mechanism to override the annotated values, in the J2EE world the annotated values are overridden by the XMLs at runtime, presumably to prevent inserting production values in a development environment -which may not be known at development time.
But which ever way I try, I cannot come up with a mechanism which allows for an override of the values while working with the annotations as an interface. I have not been able to find a setting mechanism which allows me to override a value with another (which might be retrieved from file).

Likewise I have not been able to find a mechanism to add an annotation at runtime. This then leaves me to write implementations for the interfaces (which are no real interfaces) representing the annotations. That however is disencouraged by my compiler/IDE telling me that annotations should not be used as an interface.
As a consequence I would be forced to write another interface or container class receiving the information from the annotations and/or the overriding file, but in my view that should be not necessary as the interface is already present (i.e. the annotation). And defining a interface extending the annotation interface is disencouraged as well. So I am almost forced to duplicate the information from the annotation interface, which is against all views regarding re-use in OO.

What is your view/advice on this?

]]> By: tamgo http://www.basilv.com/psd/blog/2008/working-with-java-5-annotations/comment-page-1#comment-82080 tamgo Sat, 21 Feb 2009 01:11:40 +0000 http://www.basilv.com/psd/blog/2008/working-with-java-5-annotations#comment-82080 thanks for writing this article, have spent hours looking for how to extract properties from annotations. This was the first thing that demonstrated how to do it. thanks for writing this article, have spent hours looking for how to extract properties from annotations. This was the first thing that demonstrated how to do it.

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