On Aug 23, 2006, at 10:17 PM, Alan Cabrera wrote:

David,

This sounds really interesting. If you have the time, can you give a brief explanation of what

xbean-reflect

xbean-reflect is the coolest library ever. It's basically a beefed up reflection library.

Remember before how all pluggable components had an "init(Properties props)" method? Same concept except now we throw the component class and the properties into an "ObjectRecipe" and call create(). The recipe will take the props out, convert them to the right data types, and construct the object using the right constructor and setters.

So our Containers and stuff now use constructors and setters. Same with anything in a service-jar.xml file.

http://fisheye.codehaus.org/browse/openejb/trunk/openejb3/container/ openejb-core/src/main/resources/META-INF/org.openejb/service-jar.xml? r=2679

Some code refs:

http://fisheye.codehaus.org/browse/openejb/trunk/openejb3/container/ openejb-core/src/main/java/org/openejb/assembler/classic/ Assembler.java?r=2821#l254 http://fisheye.codehaus.org/browse/openejb/trunk/openejb3/container/ openejb-core/src/main/java/org/openejb/assembler/classic/ Assembler.java?r=2821#l264 http://fisheye.codehaus.org/browse/openejb/trunk/openejb3/container/ openejb-core/src/main/java/org/openejb/assembler/classic/ ContainerBuilder.java?r=2824#l98

We also use it to construct Stateful and Stateless session bean instances.

http://fisheye.codehaus.org/browse/openejb/trunk/openejb3/container/ openejb-core/src/main/java/org/openejb/core/stateful/ StatefulInstanceManager.java?r=2835#l90 http://fisheye.codehaus.org/browse/openejb/trunk/openejb3/container/ openejb-core/src/main/java/org/openejb/core/stateless/ StatelessInstanceManager.java?r=2821#l71

xbean-finder

xbean-finder is the second coolest library ever. It's a beefed up service finder for grabbing stuff in your classpath. We use it a couple of places.

COMMAND LINE TOOL:

The available commands are in properties files in "META-INF/ org.openejb.cli/{name}", where {name} is the name of the command. See:

http://fisheye.codehaus.org/browse/openejb/trunk/openejb3/ container/openejb-core/src/main/resources/META-INF/org.openejb.cli http://fisheye.codehaus.org/browse/openejb/trunk/openejb3/openejb- itests/src/main/resources/META-INF/org.openejb.cli

Remember before how it was sort of strange that we had the "test" command hardcoded in a script, but the person may have uninstalled the itests? Well now, if you have the itests jar, the "test" command will be available. If you don't have the itests jar, the "test" command won't be available. The "test" command itself is in the itests jar. You can put any command in any jar and it will automatically become available on the command line. Remove the jar and the command is gone.

When someone types "java -jar openejb.jar start" this guy will look for "META-INF/org.openejb.cli/start". If he finds it, he'll create it and execute it. If he doesn't find it, he'll list the available commands by enumerating over all the files he see's in the classpath under the "META-INF/org.openejb.cli/" directory.

http://fisheye.codehaus.org/browse/openejb/trunk/openejb3/ container/openejb-core/src/main/java/org/openejb/cli/Main.java?r=2708

An extra cool thing is that each command has in it's properties a "description" property. This is localized, so if the VM locale is "pl" it will look for a "description.pl" property and use its value when printing command line help. Hey Jacek, you want to make OpenEJB the first open source container to have command line tools in Polish?

I'd like to give Jeremy Whitlock a big shout-out for doing such a bang up job on this. He and I worked out the idea and white-boarded it in the wiki, then Jeremy went off and coded up the whole thing! It was fantastic.

SERVER SERVICES:

We also use the xbean-finder to create our Server Services (aka. protocols). Our ServerService implementations are in properties files under "META-INF/org.openejb.server.ServerService/{protocolName}"

http://fisheye.codehaus.org/browse/openejb/trunk/openejb3/server/ openejb-server/src/main/resources/META-INF/ org.openejb.server.ServerService/admin http://fisheye.codehaus.org/browse/openejb/trunk/openejb3/server/ openejb-ejbd/src/main/resources/META-INF/ org.openejb.server.ServerService/ejbd http://fisheye.codehaus.org/browse/openejb/trunk/openejb3/server/ openejb-telnet/src/main/resources/META-INF/ org.openejb.server.ServerService/telnet http://fisheye.codehaus.org/browse/openejb/trunk/openejb3/server/ openejb-http/src/main/resources/META-INF/ org.openejb.server.ServerService/httpejbd

The very first time a ServerService is constructed, we squirt the properties file into the openejb/conf/ directory so the user can edit it. The properties files for ServerServices are very xinet.d like. For example, here is the definition of the "admin" server service:

    server      = org.openejb.server.admin.AdminDaemon
    bind        = 127.0.0.1
    port        = 4200
    disabled    = false
    threads     = 1
    only_from   = localhost

You can reconfigure the "admin" server service, for example, via the properties file in openejb/conf/admin.properties. Or you can do it on the command line as such:

<in-a-shell>
$ ./bin/openejb start -Dadmin.bind=192.168.42.13
OPENEJB_HOME=/Users/dblevins/work/openejb1/target/openejb-1.1-SNAPSHOT
OpenEJB 1.1-SNAPSHOT    build: 20060420-2356
http://www.openejb.org
resources 1
OpenEJB ready.
[init] OpenEJB Remote Server
  ** Starting Services **
  NAME                 IP              PORT
  webadmin             127.0.0.1       4203
  httpejbd             127.0.0.1       4204
  telnet               127.0.0.1       4202
  ejbd                 127.0.0.1       4201
  admin                192.168.42.13   4200
-------
Ready!
</in-a-shell>

You can override any server service property in the same way. Here are a bunch more examples:

 Option: -D<service>.bind=<address>
   openejb start -Dejbd.bind=10.45.67.8
   openejb start -Dejbd.bind=myhost.foo.com
   openejb start -Dtelnet.bind=myhost.foo.com

 Option: -D<service>.port=<port>
   openejb start -Dejbd.port=8765
    openejb start -Dhttpejbd.port=8888

 Option: -D<service>.only_from=<addresses>
    openejb start -Dadmin.only_from=192.168.1.12
    openejb start -Dadmin.only_from=192.168.1.12,joe.foo.com,robert

 Option: -D<service>.threads=<max>
    openejb start -Dejbd.threads=200

 Option: -D<service>.disabled=<true/false>
    openejb start -Dtelnet.disabled=true

IN THE FUTURE:

I'd like to extend this overriding to *anything* in OpenEJB that uses properties.

openejb start -Dcmp.PoolSize=200

On a similar note, I've posted in the past about using entirely properties to configure the server and containers with no need for any kind of xml config file. I'll dig that up and repost.


Anyway, I'm sure this is more than you asked for :)

I've pulled this information from various sources in email archives, svn and some from my head. I spent a couple hours writing this email, is there anyone who might be interested in putting this info in the wiki and formatting it all nicely?

Thanks,
David


is and how they are used?


Regards,
Alan

David Blevins wrote:
On Aug 22, 2006, at 1:47 PM, Jacek Laskowski wrote:

Hi,

The subject says it all - where/how's XBean used in OpenEJB 3?

So far, I've worked in the xbean-reflect module (which I love) in a few places, assembly and protocol creation IIRC. We use the xbean-finder all over. And Dain did the xbean-spring work, which gives us an alternate way to assemble OpenEJB. Definitely some work that can be done there -- the xml format is still in prototype stage and could be improved.

There are a couple modules of OpenEJB origin that were seeded when XBean was at Codehaus, xbean-telnet and xbean-classpath. Both were moved over so ActiveMQ, ServiceMix and others could use them. The xbean-telnet module which is based on our telnet code and has since been cleaned up a bit by Hiram for ActiveMQ -- he's pretty good at making things look organized. The xbean-classpath module is based on a chunk of our embedding cod; the part that can shove classes into the classpath "forcefully" if needed. Always been meaning to work those back in.


Is anyone working on using more features of XBean in OpenEJB3 (if
there's any left out ;-))?

I'm not currently working on anything, but I hope to start prototyping an idea i had a couple weeks ago where we put ".xbean" files in our server directories that say what they are (conf dir, beans dir, logs dir, libs dir) and we wouldn't have to assume they were named a specific thing or in a specific location anymore. People could put the directories where ever they wanted, or in some cases (libs and beans) have as many of them as they want. Still a rough idea in my head and I have the urge to make it capable of doing a lot more, such as a general-purpose metadata system. You never really know till you start working on it.


Shall I
expect more to come or do I need to roll up my sleeves and do it
myself? ;-)

Both :) Overall, it's a "scratch your itch" based system. So if you have an itch, you're encouraged to scratch it :)

As long as there are ideas, there'll be code to write and consume :)

-David

Jacek

--Jacek Laskowski
http://www.laskowski.net.pl




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