Eclipse hints, tips, and random musings

Ingress CAFÉ (Consolidated Application Foundation for Eclipse) was selected as the Best Application Development Tool at LinuxWorld Conference & Expo this week. Congratulations!

Dmitry Leskov introduced me to Excelsior JET at JavaOne this year.

Excelsior JET 6.5 will enable you to compile your Eclipse RCP application to a native code executable and distribute it without the original class/jar files.

My first question, when Dmitry showed me JET in action was whether or not it supports the OSGi dynamic runtime. The answer is yes (which is reflected in the FAQ): even with your RCP application compiled using JET, you can still dynamically install and load OSGi bundles at runtime.

The first beta of Excelsior JET, supporting Linux and Windows, is available now. I’ve only just started playing with the Linux version, but it looks promising.

I’ve got some numbers from from the usage data collector for the month of July. It’s the first full month of real data. Currently, I’ve only got data for commands, views, editors, and perspectives used; the information is restricted to only show those entries that start with “org.eclipse.”. You can change the sort order of the table by clicking in the columns.

I haven’t been able to update the “project proximity” report. There’s just too much data for the query I’m running. Once I optimize the query, I’ll update that report too.

I generally enjoy reading Jeff Atwood’s Coding Horror blog. Yesterday his post, Quantity Always Trumps Quality, made me think of two things. First, the thoughts conveyed are exemplified at Eclipse: we value code over specifications; code is written, mistakes are made, lessons are learned, and everything gets better in the process. Second, it made me think if advice I give new grads and new hires: write lots of code.

Mistakes are okay so long as you learn from them. Oh… and be careful what you decide is API, you may have to live with it for a long time.

I blogged a while back about the potential use of a bus for delivering property change notifications in place of the very common observer pattern. A reader commented that the exact service I need to implement that sort of thing is already available in the form of the OSGi Event Service. An implementation of this service is provided by the Equinox project.

I’ve updated part of the Eclipse Expense Expense Reporting Tool example to make use of the service.

I updated my business domain objects to post events detailing their changes through the EventAdmin service. This was made relatively easy owing to the fact that I had already implemented those objects with a common superclass. I added the postEvent(…) method to that common superclass:

	void postEvent(String propertyName, Object oldValue, Object newValue) {
		EventAdmin eventAdmin = getEventAdmin();
		if (eventAdmin == null) return;

		Properties properties = new Properties();
		properties.put(SOURCE, this);
		properties.put(SOURCE_TYPE, this.getClass().getName());
		properties.put(PROPERTY_NAME, propertyName);
		if (oldValue != null) properties.put(OLD_VALUE, oldValue);
		if (newValue != null) properties.put(NEW_VALUE, newValue);

		eventAdmin.postEvent(new Event(PROPERTY_CHANGE_TOPIC, properties));
	}

It’s pretty straightforward. The first thing it tries to do is obtain the service. The getEventAdmin() method uses the bundle activator (and a ServiceTracker) to find a service that implements EventAdmin. If no such service can be found, we bail out and pretend that nothing happened. If we do find an EventAdmin, we create and post an Event instance. The postEvent method posts the event to be delivered asynchronously; the sendEvent method delivers the event to waiting handlers before returning.

The Event instance is packed with properties. The nature of these properties are application-specific. In this case, I’m including properties that tell me what has changed and in what object. The event also has a "topic". The topic is used to determine how the event is delivered; only event handlers that are listening for this particular topic will be informed of the event (there’s a little more to it than this). It’s very much like the Java Messaging Service (JMS).

This is only part of the story. Publishing events through the event service is only interesting if there are subscribers on the other side. I’ll talk about what I’ve done on that side sometime next week…

Participation in the Usage Data Collector has been nothing short of outstanding. As of this moment, we have gathered usage data from more than 22,000 users (more than 20,000 new participants this month alone). The usage trends page shows this in a cool graph.

The other reports that we’ve generated are a little out of date since running those reports is pretty darned time consuming. I’ve optimized the database for storage space first, writes second, and reading/reporting third. I’m going to spend some time today making reading a little less painful so that we can actually run those reports.

22,000 users participating. Staggering.

Try this in Eclipse Ganymede (one of the variants that includes the Java development tools):

Copy this text:

System.out.println(new Date());

Bring the Package Explorer into focus (make sure that none of the existing projects is highlighted) and select “Paste” from the context menu.

JDT will build the project, package, class, and main method for you. How cool is that?

There’s a lot more hidden in the new and noteworthy. I’m in love with the rich hovers.

I just created bug 239808, Eclipse IDE for Education, as a proposal for a new component in the SOC project. Please add your comments on the bug. While you’re at it, we’re looking for volunteers…

The proposal originates from the need to provide a streamlined environment to help first-year undergraduate-level university students ease into the combined challenges of learning about programming, programming languages, and an integrated development environment.

Initial work has focused on providing a simplified Java development perspective with a view that makes it much easier to create packages and classes for assignments. Future work may include streamlining of other workflows, views, and editors. I think this project has a lot of cool potential. Imagine integrating some ECF code that would allow a student—with the push of a single button—to share their editor with a teaching assistant to get help remotely. Or another button that—with a click—packages up the work and submits it for marking.

As a general rule, the SOC project is intended as a place for mentored student work done under the Google Summer of Code (GSoC) programme. However, we were careful when we created the project to allow for flexibility. The spirit of the project is to provide a place for student and student-related work to occur. I believe that the Eclipse IDE for Education falls into the student-related category.

I believe that the Eclipse IDE for Education has many merits that bring value to the SOC project. In particular:

1. It will be long-lived and thus should provide some much-needed continuity to the project
2. We have started to attract other professors and researchers to get involved. Their involvement will raise the awareness of the SOC project
3. Some students are bound to get involved. It seems like a natural thing for SOC 2009 student projects.

Initial committers on the new project will likely all be SOC mentors. However, I do anticipate that we will pick up several students once we get the project underway. In my fantasy scenario, the component will act as a lightening rod for student involvement.

There’s something about the Java Forum Stuttgart conference that I really like. The conference is a little on the large size (I believe that I heard that there were 1,200 attendees) which gives the exhibit area a really busy feel. Good busy.

As a speaker, I can’t say enough about this conference. They take care of us. Every year they get us great gifts. The best part is that the gifts tend to have some local tie-in. This year, they gave us coffee and tea from local providers. It came with a little booklet that, if I could read German, would tell me all about the company and how it is a cornerstone of the Stuttgart business community. That personal touch is nice. It also helps that they assign me my very own personal assistant (who I assume is the very own personal assistant for a couple of other folks). This year, she remembered my Modelleisenbahn hobby and had a map ready for me pointing out the locations of local stores.

My talk went very well. I presented Mylyn to a standing room only crowd (apparently there were about a dozen people in an overflow room). Here’s what they looked like from my perspective.

I decided to mix things up a bit this time through and started with a demo. I went out on a bit of limb and just started implementing part of the solution for bug 237658. The first thing I did was create subtask for this bug. With Mylyn 3.0, new tasks (or subtasks) can be created for a repository without actually submitting them (which was handy as I didn’t notice the Ethernet cable which I’m sure would have given me Internet access if I had thought to try it). So I created the subtask and just started into changing the Expenses (EBERT) application to channel change events through the Equinox event framework. I plan to submit the new subtasks to Bugzilla and check the code into a new branch sometime soon (I’m feeling a little lazy right now).

I asked the audience to try not to get too taken by the Equinox stuff and focus on the task-oriented development process (I really did want to get them thinking a bit more about Equinox and the Examples project). In the process, I managed to show off the Bugzilla integration, and the Über-cool context-based filtering. I wrapped up with a quick pass through the slides to reinforce what I demonstrated. The net result of the demonstration was the same as last year: I felt like a rock star. People love Mylyn.

One of the disturbing take-homes from the session is the number of developers who apparently do not use an issue tracking system of any form. Mylyn supports, Bugzilla, JIRA, Trac, XPlanner, CodeBeamer, and more. But there were a lot of questions about how Mylyn can be used to share tasks without a repository (I showed how you can drag tasks out of the Task List view onto the file system and then from the file system into a different workspace’s Task List; I guess that works).

I rounded out my week by talking about Ganymede with two different audiences. The first audience got to listen to me two hours after I got off the plane. It was not one of my best performances. The crowd today in Zürich seemed to have had a better time; clearly a few extra hours of rest make big difference.

I leave you today with a picture I took of Doug Clarke from the EclipseLink project from last night’s Stammtisch.

It’s good to be king.

If you have a question about some Eclipse project, the newsgroups are your best bet.

If you’re not sure what group is appropriate for your question, post it on newcomer. Posters to newcomer are often redirected to other newsgroups, but newcomer is a good starting point since a lot of very knowledgeable people watch the group pretty carefully.

The newcomer group may be misnamed. While it is indeed for newcomers, it’s not exclusively for them. Lots of folks who have years of experience with Eclipse post their questions there.

The newcomer newsgroup isn’t just for newbies. Can you think of a better name?