Hi David and Donatas,
I've been working some more on creating an OpenEJB plug-in that
would
allow applications held in other plug-ins to be deployed when their
plug-in is activated.
This is based on a single OpenEJB server plug-in that contains all
of
the OpenEJB libraries and some additional classes to activate and
manage
the deployment of other applications.
I've managed to get some examples working, and thought it would be
good
to share my efforts with you so far.
The attached Zip file contains three Eclipse projects, the server
plug-in and a simple EchoServer stateless bean application and a
client.
The server plug-in I've created allows for deployment when a plug-in
registers a new OpenEjbApplication as a service. The OpenEJB server
plug-in listens for service requests and automatically deploys and
undeploys an application when the service starts and stops.
The only problem with this approach is making sure the application
plug-in is activated before the client tries to use it (e.g., by
making
a context lookup). This is handled in the activation code of the
client
by forcing the application plug-in to start.
The code I've written allows additional application properties to be
included as part of the normal Eclipse service creation. You can
get the
OpenEJB server plug-in to load properties from files included in the
application plug-in and any fragments (I use META-INF/
openejb.properties
in my EJB plug-in). Because of the Eclipse plug-in/fragment
arrangement,
if you include a file with the same name in a fragment, its
properties
will override those found in the host plug-in. However, the order of
fragment processing is undefined, and so you cannot reliably
override
properties between fragments.
Also, the properties are processed using the Eclipse variables API
to
handle string substitution, so that, for example, a property can
include
${user.home} and get this expanded before it is passed to the
OpenEJB
server. I automatically add all System.getProperties() to the
variables
available, as well as any properties added by the application.
I need this overriding and substitution to allow my test fragment
project to override the database URL of the main EJB plug-in to
use a
different test database, and to have the database location depend
on the
user's home directory.
To get the example working, you will need to create a folder in the
openejb.server project that is a link to the OpenEJB 3.1 lib
folder in
the distribution. Also, make sure that all of the OpenEJB
libraries are
included in the project build path and exported by the project.
You are likely to have many more questions about this code than I've
provided answers to in this short email, but I thought it was time
share
where I have reached so far.
Regards,
Deryck
--
Dr Deryck F Brown
Software Engineer
Ziebel UK Ltd
Unit A, Broadfold Road,
Bridge of Don,
Aberdeen AB23 8EE
Tel: 01224 227227 (X143)
Fax: 01224 703146
Skype: ziebel-deryckb
Web: www.ziebel.biz
<example.zip>
