Debug Blackberry app inside Eclipse

Once you get your eclipse environment setup, it is pretty straight forward to debug your app, thanks to Blackberry JDE, 4.1 and higher comes with JDWP implementation.

Let's first start JDWP, from Start --> All Programs --> Research In Motion --> Blackberry JDE 4.?.? --> JDWP. In this interface, the first main tab "Simulator" configures the simulator to lanch when debugger connects and the other behaviors. Please make sure that in the "General" tab "Launch simulator when debugger connects" is checked. In the second main tab "Communications", you can change the port JDWP listens to. This is the port we will connect to from our eclipse debugger.

With JDWP running, we can go back eclipse. Before we get started, we should increase the debugger's timeout threshold. Start elcipse, go to Window --> Preferences --> Java --> Debug, at the bottom of the dialog, increase the "Debugger timeout" and "Launch timeout" to 10 times longer. :) It is much needed unless you have a monster computer with multiple cores and multiple gigs of memory.

To config the debugger, go to Run --> Debug... In the dialog, select "Remote Java Application" from left hand list, then click on the "New" button; now at the right hand pane, give it a meaningful name, check the remote host and port matches JDWP's, then go to the third tab "Common", check "Debug" option in "Display in Favorites menu" so you don't have to open this dialog next time. Click "Debug" button if you are ready, otherwise click "Close" button to save the configuration.

Now the fun part begins. Edit code, run the ant task to deploy, set break point, click on the debug icon, and repeat this cycle.