James Todd's Blog

February 2005 Archives

myjxta :: persistent eye candy

polo rolled in the latest prefuse lib whereby a myjxta user can now copy aside a myjxta graph by placing focus on the graph and simply entering ctrl-e. very cool! there's much more we can do with this feature.

MyJXTA :: use it - learn it - do it

Java == platform independence
XML == application independence
JXTA == network independence

Secure End-to-End Computing

in my ears: Gravity Kills/Gravity Kills/Goodbye

MyJXTA :: co-owner :: Jeff Moore (aka polo)

Jeff Moore, aka polo, is now a MyJXTA project co-owner. I had the good fortune to meet Jeff while attending Linux World in Boston last week and truly look forward to his contributions moving forward. Jeff dove into MyJXTA head first and fleshed out, among other things, the prefuse eye candy. great stuff!

MyJXTA :: use it - learn it - do it

Java == platform independence
XML == application independence
JXTA == network independence

Secure End-to-End Computing

in my ears: U2/Achtung Baby/One

JXTA :: ext:config explained

ext:config library is a JXTA configuration framework that grew organically via a number of real world venues and has been consistently honed through a steady application of refactoring TLC.

The ext:config wiki is nearly draft complete at this time and includes:

• dependency listing
• API (object model)
• profile (declarative model)
• ui
• hands on runnable code samples
• associated resources

A few sections marked as wip remain and are currently under development but for the most part this document is comprehensive and practical.

MyJXTA :: use it - learn it - do it

Java == platform independence
XML == application independence
JXTA == network independence

Secure End-to-End Computing

in my ears: The Chemical Brothers/Life Is Sweet/ Live Is Sweet

JXTA@LinuxWorld.Boston

JXTA will represent at next weeks Linux World Boston edition. I'll be in town 02.14 - 02.16 so if anyone in the BlogEther happens to be in the area and wants to get together to tip a few and talk smack I'm game.

Ok, why did I need an iPod? Given I'm new to the magical Apple Koolaid Elixir and at present amd still happily riding out the initial Mac/OSX buzz I had planned on getting an iPod in time. When I looked at the length of time I'm going to be on a plane over the next couple of days, I decided to speed dial the timeline a bit on that little swag purchase ... and my lovely wife has been very forgiving.

JXTA will have a presence on the pavillion floor. I'll be there along with 2 groups of folks from the JXTA community. polo, a fellow MyJXTA code slinger, will be there as well so I'm looking forward to hashing out some ideas, with beers in hand, whilst we are both in the same timezone.

This year, the demos include:

• BBN Technologies - Sensors and Robot Coordination Application
• proXimio - online community building
• JXTA C - JXTA C implementation
• MyJXTA - JXTA reference application
• NetMap - JXTA Network Visualisation

Get Connected!

MyJXTA :: use it - learn it - do it

Java == platform independence
XML == application independence
JXTA == network independence

Secure End-to-End Computing

in my ears: Paul Oakenfold/Ibiza/Transit

My MyJXTA

Running MyJXTA is relatively trivial, either via WebStart or source. While WebStart totally rocks I encourage folks to try building and running from source. I'll get to why in a bit.

MyJXTA runs, by default, on the "Public JXTA Network," affectionately called the "PubNet." This is basically an massive sandbox with which JXTA developers can deploy their wares and the JXTA curious can scratch their itch. A forum of sorts.

More frequently we've been asked "How can you run MyJXTA in a private network" to which this entry should shed a bit of light. The reasons vary but I believe the principal motivation behind this question is to to fundamentally expose colleagues and management, potentially skpetics, to the wonders of JXTA yet run it within a safe and well known environment. Being all for "enlarging the pie" here's a short little recipe on how to go about deploying MyJXTA on a "private network."

At this point in time, you will need to get the source. Go ahead. Don't be shy. 2 Ant commands and you will be ready to bake.

In order to change MyJXTA's default PubNet behaviour one must, today, edit 2 configuration files:

• src/net/jxta/myjxta/resources/myjxta.xml
• src/net/jxta/myjxta/resources/profile.xml

myjxta.xml is the principal MyJXTA configuration file whereas profile.xml is the JXTA Configuration Extention, aka ext:config, configuration file. More on the later at another time.

Firstly, myjxta.xml. All that needs to be added to this file is the "private network" deployment data, that being:

• id
• name
• description

note: name and description are optional but for usability reasons you should include meaningful values

Now, all that needs to be done is add the aptly named attributes to the network data structure, as follows:

  <network id="urn:jxta:uuid-01234566789abcdef0123456789abcde02"
    name="My MyJXTA"
    description="JXTA Rules">

More information regarding JXTA's data structures, et al can be found in spec.jxta.org.

Ok. That was pretty easy. What's next. Oh yeah, the profile.xml. This file describes the type of JXTA network environment the hosting application will bootstrap into. The first thing we'll need to modify is to specify an alternative bootstrap address, Boostraps are simply well known peers that are utilized to establish the intial network context. For this, we will assign a rendezvous and relay boostrap URI:

    <rendezvous bootstrap="file:///tmp/bootstrap.txt"
      discovery="false">
    ...
    <relays bootstrap="file:///tmp/bootstrap.txt"
      discovery="false">

The bootstrap can be any valid URI that lists seeding context JXTA peers. You can see the PubNet bootstraps here:

• rendezvous
• relays

With that, all that remains is to disable multicasting. This is actually done by convention, mine, at present although another option is to simply change the multicast address. The included multicast address in the sample below is not valid. Sticking to convention for the moment, we simply need to disable multicast. To do so, we set the enabled attribute of the multicast descriptor to "false:"

        <multicast enabled="false">udp://12.34.56.78:1234</multicast>

That's it. Now all that remains is to place the cake into the oven and let it bake. Thusly, we turn to Ant:

  % ant run

At this point, you are running a private network deployment of MyJXTA! Not that painful and rather enabling in the overall scheme of things. That being, to actively infect those around you with the "connected network" vision that is JXTA. That we no longer have to put up with "static addressing." Free them. Free their minds. [flash matrix imagery]

Back to the source. The above, while k3w1, relatively painless and all it is not, well, all that intuitive for those that don't care about angle bracketed text, et al. One of the big "MyJXTA.next" items is "preferences" to which this and a multitude of other like features will be customer [I'm an xp fan ... people you care about and/or connect with are not users]. There is a wealth of preferences features that when appropriately exposed will truly put the My in MyJXTA. If you have an interest in helping to sling some MyJXTA prefernces code, don't be shy.

To close, I am soooooo loving my shiny new iPod. Golden! I'll explain my reasons for getting it at this time but my wife, who knows better, isn't buying it for a moment.

MyJXTA :: use it - learn it - do it

Java == platform independence
XML == application independence
JXTA == network independence

Secure End-to-End Computing

in my ears: Paul Oakenfold/Ibiza/Arena

This work is licensed under a Creative Commons License.