Experimental Physics and
Industrial Control System

"J. Lewis Muir" <[email protected]> · Tue, 11 Jan 2011 09:40:00 -0600

On 1/10/11 6:12 PM, Mitch McCuiston wrote:
>  I've been thinking about implementing an annotation based mapping of
> Java objects to PVs.  I thought I would ask the community if something
> like this already exists before I take it on.  If it doesn't exist,
> would anyone find value in this.  The idea is loosely based on how
> Hibernate maps Java objects to a relational database, although the
> read/write semantics are a little different.  Here is an example.

Hi, Mitch.

I don't really see why one would use annotations for this.  I'd
certainly be in favor of an object implementation in Java above JCA/CAJ
(or perhaps added to it) that would provide a simple and easy-to-use API
for interacting w/ EPICS PVs.  At a minimum, it would provide an EpicsPv
object and make it easy to get and set values, easy to register interest
in a value change, do blocking puts, and more.  I've written such an
implementation, but there are a lot of changes and improvements it needs
before I'd make it publicly available.

So I'd say, yes, there's a need for a simple and easy-to-use API on top
of JCA/CAJ -- something perhaps along the lines of Matt Newville's Epics
Channel Access for Python
<http://cars9.uchicago.edu/software/python/pyepics3/> which provides a
PV class.  But I don't see any reason to use annotations.  Why do you
want to use annotations rather than just regular objects?

Lewis

-- 
J. Lewis Muir
Software Engineer
IMCA-CAT

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System