Category Archives: Programming

Remote debugging Tomcat with Eclipse

When you’re running a Tomcat server on your own machine for development purposes, it’s pretty easy to tie it to Eclipse.  When that Tomcat instance (or, in my case, instances) are running as a service, without the benefit of the control panel, it gets a little harder.  Especially if it’s not a traditional web application, but a desktop app with a supporting web back-end.

Here’s how to debug a Tomcat server with Eclipse when it’s running as a service.  This example assumes that the server is at localhost, and that you’ll be debugging on port 5003 (your choice, so long as it’s available – and it can’t be the port that that Tomcat is already on).

Firstly, when you start your Tomcat service you need to pass a few additional options:

set JPDA_TRANSPORT=dt_socket

Next, the line that actually launches the service needs to pass those options in the JvmOptions parameter:

--JvmOptions "-XDebug;-Xrunjdwp:transport=%JPDA_TRANSPORT%,address=%JPDA_ADDRESS%,server=y,suspend=n;-DJAVA_HOME=...

Important: no white-space in there.

Lastly, create the debug configuration in Eclipse:  Run -> Debug Configurations, add a new Remote  Tomcat Application.

  • Connection Type: Standard (Socket Attach)
  • Host: localhost
  • Port: 5003

Et viola, start this debug configuration to attach to the server, then launch your application as normal.

Obscure Ant build errors

I’ve been using Eclipse at work now, the first time I’ve done more than toy with it.  Along with Eclipse are the attendant tools – Ant, Maven, TomCat and ClearCase (oh yes, ClearCase).

So, Ant. I came across a situation where the build was failing to deploy the WAR files to TomCat, with the following error:

build.xml:887: C

Not much use there.  As it turns out, the solution was both simple and cripplingly unintuitive: replace “file://” with “file:///”.  The extra slash makes all the difference.

For example:





Picsie updated to Alpha 1.3

Picsie has a minor new feature – a little UI improvement to make it easier to load more than one window at once.

When you load an image or video with Picsie, it checks to see if any other Picsie windows are open.  If not, it opens in the middle of the screen.  If Picsie is already running, it opens wherever Windows puts it, so it doesn’t cover the previous window.

Alpha 1.3 (7 July 2010)

  • Installer (~75KB).  This will set up your file associations for you.
  • Standalone .exe (~200KB).  Use this if you already have Picsie installed and you just want the latest version.  Just drop it over the existing one.

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Picise updated to Alpha 1.2

A couple of quick fixes to Picsie.

Alpha 1.2 (20 June 2010)

  • Installer (~75KB).  This will set up your file associations for you.
  • Standalone .exe (~200KB).  Use this if you already have Picsie installed and you just want the latest version.  Just drop it over the existing one.

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LaTeX Includes

Latex offers a very nice way to divide large documents into manageable files – the include command.  Combined with the includeonly command you have a very powerful method of compiling your document.

Typically,  each included file is a chapter – this is apparently how it was designed, and is certainly how I – and every other LaTeX user I know – use it.  Today I decided that one chapter was far too big, and split it up into a few smaller files for easy management.  Took seconds, no problem.

Only later, when I was annotating a hard copy for my supervisor did I realise that every include finished with an implicit clearpage.  Just what you want when you’re starting a chapter, and so I’d never noticed it.  When you’re starting a new section though, that’s not what you want.

In this case, use the input command  – same format, same effect, but no implicit clearpage.  You lose the includeonly functionality, but it fixes your section breaks.


Problem: Unwanted page breaks around include statements.

Solution:  Use the near-identical input command instead.

Unexpected LaTeX!

Somehow I forgot to mention that as well as delving into the world of C# I’m just finishing up my PhD thesis.  Having experienced the horrors of trying to manage a large document in Word, I set about learning to use LaTeX, which for this kind of work is superior in just about every imaginable way.

Once you decide on a style sheet, LaTeX pretty much manages everything for you, and lays it all out beautifully.  When it works, it works sublimely.  When it doesn’t work, you can really end up stuck.

So, I’m going to post a bunch of LaTeX problems too, since it can be really hard to find solutions when you don’t know the right vocabulary.

Mouse events on DirectX.AudioVideoPlayback Controls

This is the issue that finally pushed me over the edge to setting up this blog.  Normally when you have a coding problem, you find the answer fairly quickly and move on.  Sometimes though, the solution remains elusive.  Then you put the answer on a page of your own, to help out the next weary traveler.

Which bring me neatly to…


I recently posted my lightweight media viewer, Picsie.  As well as images, it also handles some formats of videos.  The video playback was largely on a whim when I stumbled across the wonders of Microsoft.DirectX.AudioVideoPlayback.  The code to set it up and use it is endearingly simple:

Microsoft.DirectX.AudioVideoPlayback.Video videoPlayer
	= new Microsoft.DirectX.AudioVideoPlayback.Video(filename);
videoPlayer.Owner = videoPanel;

Give it a video file and a control to draw on, and tell it to start.  Some form of error handling is probably wise too.

All well and good so far.  A few buttons to control playback, and you’ve got a basic but functional video player.  My problem came when I wanted the video to have the same control system as the rest of Picsie – left-double-click to centre, right-click to exit, drag to move.  These all worked for images, but when I came to test it on videos, only the drag code seemed to work.

It was pretty simple to diagnose.  MouseDown, MouseMove and MousePress all continued to function as before.  For reasons unknown, the Video object ate any Click, MouseClick, DoubleClick and MouseDoubleClick events.

At this point the Internet failed me.  No solutions, and I had two features no longer working:

  • Right-click to exit
  • Double-click to centre

Not able to find a way to get my events back, it was fairly trivial, if a little messy, to move the right-click code to the MouseUp event, with a little jiggery pokery to make sure it was a click and not a drag.  On the other hand, did I really want to write all the code to check for and handle double clicks myself?  No, no I didn’t.  Thankfully, I didn’t have to.  MouseEventArgs has a “Clicks” property (when did that appear, and why did nobody tell me?), which you can use to fake a double-click event:

private void Panel_MouseDown(object sender, MouseEventArgs e)
	if (e.Button == MouseButtons.Left && e.Clicks == 2) {

And there you go.  I never did find out why the Video object ate my events.  There’s probably a really simple solution somewhere, or I did something boneheaded, but more than one person faced this problem and never found an answer, so here’s mine.  Fake clicks and double-clicks.


Problem: AudioVideoPlayback.Video eats MouseClick and MouseDoubleClick events.

Solution: Check for double-clicks using the MouseEventArgs “Clicks” property in the MouseDown/MouseUp events which aren’t eaten.


Downloads – Alpha 1.10 (10 November 2015)

  • Installer (~75KB).  This will set up your file associations for you.
  • Standalone .exe (~200KB).  Use this if you already have Picsie installed and you just want the latest version.  Simply drop it over the existing executable.

Picsie is a very lightweight image and video viewer, with an emphasis on speed and minimal interface.   I primarily made it because while in the past I was perfectly happy with XnView, Quick Look on the Mac made it obvious how much Windows was missing something similar.

A while later I saw VJPEG which did pretty much exactly what I wanted.  Unfortunately it lacks a few features I like, so I set about making my own.
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