Principal Software Architect Discussion Topics

Recently some friends at work asked whether I would consider mentoring them on topics associated with performing a principal software architect role within an organization. Given our limited time available we decided to meet for an hour every two weeks to discuss preassigned topics. Click here for a syllabus of the discussion topics and links to related articles.

Remotely Debugging Java Applications

Totem’s software is written as a single Java application executed when power is first applied to the robot.  To speed up the development process the software is developed on a separate MS Surface tablet and then downloaded to the robot.  In most cases the software is tested in the Java development environment hosted on the Surface.  However there are occasions when the software must be tested on the robot itself (e.g., testing modules that interact with hardware).  Thankfully Java supports remote debugging – the ability to use the Java development environment to remotely debug the software executing on the robot.  This article describes the configuration required to accomplish remote debugging of the robot’s Java applications, assuming Eclipse is used as the host Java development environment.

Verify Java Run-Time Compatibility

On the Surface PC invoke the Eclipse Preferences dialog, then navigate to Java > Installed JREs:

eclipse

On the Raspberry Pi type “java -version”:

piRuntime

Both JREs should use the same major version number – 1.8 in this case.

Create a Shell Script to Execute the Application with a Remote Debugging Listener

Java applications are packaged for deployment as a single standalone “jar” archive file.  Contained within the jar archive are the various application implementation artifacts (e.g., Java class files, images, etc).  Executing the application is accomplished by invoking the “java” command and passing the filename of the application’s jar file as a parameter.  To enable remote debugging additional parameters are provided specifying the network port on which java listens for connections by remote development environments.  Unfortunately several parameters must be specified containing rather cryptic syntax.

Rather than type a lengthy command each time we want to run the application we can create a shell script that provides a short, easy-to-type alias instead.  For example, the debug.sh shell script shown below executes the application within jar file totem.jar while creating a remote debugger listener on port 8000:

javaRemoteDebugging

Now each time we want to remotely debug the totem.jar application we can simply type ./debug.sh to start the application.

Create an Eclipse Remote Debugging Configuration

Within the Eclipse development environment create a new remote debugging configuration by opening the Debug Configurations dialog.  Select the line titled Remote Java Application and then click the New icon located  at the top of the list.  In response Eclipse will create a new entry and display a panel listing the entry’s various configuration options.  The following image illustrates typical configuration values, assuming the listener is listening on port 8000 as shown in the previous step:

eclipseRemoteDebugging

At this point the configuration is complete.  To remotely debug the application the first step is to start the application running on the robot by invoking the ./debug.sh command within the Raspberry Pi’s command window.  Then click the Debug button within Eclipse’s debug manager window (or invoke the link within the Debug menu) to connect the Eclipse debugger to the running application.  You can now set breakpoints and examine variable values in real-time as the application executes on the robot.

The Art of Creating Powerful Presentations

Have you wondered why Apple’s presentations continually WOW audiences while Microsoft’s don’t?  In my opinion the reason listed in this Presentation Zen blog entry is spot-on!

“Simplicity means the achievement of maximum effect with minimum means.”
— Dr. Koichi Kawana

The Presentation Zen website contains many other valuable observations and useful resources for presenters (e.g., “Where to Get Good Images“).  I highly recommend you check it out.

Steve

Using Hibernate JPA within Glassfish

Glassfish provides TopLink as its default JPA provider.  However it’s possible for applications to instead use Hibernate within a Glassfish deployment.  The challenge is to determine where to install the Hibernate libraries so that the application references Hibernate instead of TopLink.  While googling for an answer I saw several recommendations suggesting that the Hibernate libraries be installed within Glassfish’s server lib directory, thereby in essence removing TopLink and replacing it with Hibernate. Continue reading →

Calling EJB 3 Session Beans from Spring

There’s been quite a bit of discussion these days as to which technology is best for developing enterprise applications – EJB 3 or Spring?  In my view it’s not an “either-or” question, both technologies have their strong points and use within an application.  When deciding which technology to use, my answer is “simplicity wins”.  Given a particular component to implement the best technology is the one that 1) accomplishes the goal, 2) minimizes complexity, and 3) is the quickest to implement with the least amount of code. Continue reading →

Team Development: Reaching Consensus from Conflicting Opinions

discussionWhen developing a software application there are typically several possible solutions for a given set of requirements.  Often the “best” solution isn’t immediately obvious causing intense debates among team members with strong conflicting opinions.  Rigorous debates are actually a normal healthy part of the creative process.   The best solutions often result from the combined analysis of diametrically opposing viewpoints.  However for the sake of team morale it is critically important that team members agree to follow specific guidelines while debating.  In this blog entry I present some guidelines I’ve found helpful for engaging in intense debates while maintaining team respect and cohesiveness. Continue reading →