Using Java Web Start to Launch NetBeans
Posted by hansmuller on January 09, 2006 at 04:21 PM | Comments (23)


About six months ago I had a dream. Not the sort of dream that makes you wake up shrieking or smiling, and not the kind that brings you down from the mountain top or even gets you off the couch. Mine was the kind of dream programmers have. The kind of sloth inspired idea that comes to you while staring at the screen, wondering if there's a way to eliminate all of the mouse clicking and key pressing effort that makes you weary without actually burning calories.

I spend quite a bit of time looking at Java blogs and articles that incorporate lots of source code. Usually there's a link for zip file that contains all of the files the document refers to, and maybe a jar file with a build. Sometimes articles include direct links to source files, however scanning a pile of source code with the web browser isn't terribly appealing. The nicest way to look at code and try out APIs, is to just load everything into a Java IDE like NetBeans. Once that's done it's possible to use the editor and debugger and all of the other IDE features to explore the code. Like a real programmer should. And just like a real programmer, I'm usually too lazy to bother.

So the big idea was to write a web started app that would download a complete NetBeans project, launch NetBeans, and open the key source files in the editor. That way, if someone was reading a blog or an article about some Java project, they could click on a JNLP link - and with no additional effort! - peruse the code from within the IDE. To me, this seems like a civilized way to do business. Sadly, I wasn't able to con one of my colleagues into building such a web started app. Towards the end of last year, as Sun began to slow down in anticipation of the Christmas break, I took a crack at building a NetBeans launcher. You can try it now, by clicking on the handy launch button below. It's a signed application, because it creates a temp file and launches a (NetBeans) process on your machine, so you'll have to click through a security dialog.

To give the example launcher a try, just click the Launch button:



The launch app depends on the NetBeans OpenFile module to start the NetBeans IDE, if necessary. Sadly (at the moment) there isn't an "OpenProject" module, so the best I can do is to show a single Java source file. If the launch app is unable to locate an installed copy of NetBeans, it displays a little form that allows choosing the install directory, or downloading the current NetBeans release. I haven't tested launch very carefully (works on my machine :-) which is unwise, since part of the code to find and launch NetBeans is platform specific. It should work on Windows XP and it might work on Linux or the Mac or Solaris. I'd be happy to hear from anyone who's tried it.

The example file downloaded by the launcher, NetBeans.java, deals with figuring out if and where NetBeans is installed. I didn't pick this one file out of pride, it's incomplete and contains some moderately embarrassing hacks. On the other hand, it does all of the important work. The class is used like this:


The initialize method uses some shameful heuristics to try and figure out where NetBeans was installed. Check out the source code from within the IDE to see what I mean. It would certainly be much nicer to be able to look in a well known (per platform) place to find out what versions of NetBeans were installed and where; maybe in the future that kind of support will emerge.

You can use the launch app on you own web site, just by making a copy of the JNLP file file and replace the URL in argument element at the bottom. The current version links to the example NetBeans.java file:

<argument>http://download.java.net/javadesktop/blogs/hansmuller/launch/NetBeans.java</argument>
You don't need to copy the launch jar files or anything else. Just create a link to your version of launch.jnlp on your site, and make sure your web server is configured to support the JNLP MIME type.

This was originally intended to be a quick project that I'd finish on on the long flight home from Prague back in December. It didn't turn out that way, in part because building (usable) GUIs is always more work than you'd think. It's also because I took the opportunity to get introduced to Matisse. It's been a long time since I've been comfortable writing Swing GUIs with a tool. Using Matisse turned out to be pretty inspiring: it worked well and it greatly simplified the task of evolving a GUI. Using it was a constant reminder of all of the additional desktop app building support that should be in NetBeans. More about that in another blog.

I have a long laundry list of worthy improvements for the NetBeans launcher. I'd be interested to hear what other developers think of it and what you-all think should be changed/improved. Here are a few of TODO items from the top of my list:

Download a complete project packed into a jar file and expand that into a temp directory. Open a set of project relative source files in NetBeans.
Log errors, and warnings and provide a way to show them.
Show the main window roughly in the middle of the screen. And wouldn't it be nice to know which Screen NetBeans was already running on - if there were multiple screens.
An "OpenProject" NetBeans module. I've been assured that this wouldn't be so difficult to write. Making sure that it was deployed to the IDE, before the project was launched would be a bit of a trick.

If you'd like to look at the complete NetBeans launch project, you'll find a zip file of the complete project here. I realize that it's more than a little ironic to publish such a link. Hopefully I'll be able to support loading entire projects (not just files) in round two.

www.idomainsite.com

www.webproworld.com

hi.baidu.com

The one thing that I found dull about netbeans was that there is no "native" or previously installed reporting utility, such as crystal reports in vs2005.

This would make netbeans a much better at desktop application
development. Database operations and reporting go hand in hand.

Justin Fox