It is time for spring cleaning my hard disk at home. I am sorting/deleting files that I no longer use. I will post here files that I do not need now, but might need in the future.

So… I found a small linux shell script  that individually compiles every java file in a directory and all its subdirectories. The code is:


for d in ls
javac $d/*.java > $d/compile.txt


The text file can be found here:  batchcompile

I recently wanted to redirect the output of Log4j to a JTextPane, so as to output messages to the JTextPane using a different color depending on the severity.

I spent some time searching for information and I quickly put together a small example. The following screenshot shows the output.


The source code is available here.

I recently installed eclipse 3.3 and Java 1.6. Today I tried to use SiTra (Simple Transformations in Java) but when I tried to compile it Java started complaining on the following methods of the

The error was something about java inconvertible types. I don’t know if it is the new version of eclipse or Java 1.6. Looks like for some reason the compiler doesn’t recognise that Rule.class is of type Class<? extends Rule<S, T>>, so as to call the public <S, T> T transform(Class<? extends Rule<S, T>> ruleType, S source)

A simple solution is to ct the Rule.class expression to Class (it sounds weird but it worked).

So the transform and transformAll methods become:

For the past two days I have been working with MS Access to create an application. One of the features I wanted to create, was a parametric query that would take the value from a combobox on a form and create a report.

To be more precise I had a form with a combobox populate with IDs and names and when the user selected a specific item from the combo and clicked on a button I wanted to have a report that showed some information of related to the selected ID.

One way to do it is to create some vb code and create a select query with a “where” clause. But, that is not too flexible, caz if I want to change the query, I have to change the code.

Today I came across a more flexible solution. Parametric queries. I knew how to use parametric queries, but not in conjunction with forms. So if you want to create a parametric query related to a form, all you have to do in the query is define the parameter at the beginning like:

PARAMETERS [Forms]![formName]![ControlName] ParameterType;

In the where clause you also have to use the same notation. So for example:

where Id = [Forms]![formName]![ControlName]

and that’s it!

I was trying to convert an MS Access database I had developed to MDE. It was crashing every time I was trying to create the MDE file.

After some search on the internet I run across a Microsoft article that solved the problem for me.

The link is:;en-us;814858&spid=2509&sid=98

What it says is:

To work around this problem, you can reload the VBA project of the Access database from text and then create the MDE file or the ADE file. To do this, follow these steps:

Note Make a backup copy of the database before you start these steps.
1. On the taskbar, click start and then click Run.
2. Type msaccess.exe /decompile and then click OK.

3. Open the original .mdb file or the original .adp file that you want to save as the new MDE file or the new ADE file.
a. Press ALT+F11 to open the Visual Basic Editor.
b. On the Debug menu, click Compile <databasename>.

c. On the File menu click Save <databasename>, and then close the Visual Basic Editor.
4. On the Tools menu, click Database Utilities and then click Make MDE File or click Make ADE File.
5. In the Save MDE As dialog box or the Save ADE As dialog box, locate the folder where you want to save the MDE file or the ADE file, type the file name in the File name box, and then click Save.<databasename>

I tried it and it and it works like a charm! Apparently I had deleted some forms and there was some VBA code related to those forms that was still there. With the decompile option not only did I manage to create an MDE file, but I also reduced the size of the db by almost 1MB(!!) after I compacted it.

From now on I am going to use the /decompile option every time before I deploy a new version of access.

As I was searching for something on google, I saw an ad at the bottom of the page. The ad was about the Davinci code new movie that is coming out. I clicked and found a sudoku like puzzle, related to the movie. The puzzle is explained in the following two pictures (description can also be found on:

Well… it is clearly a very simple problem for a constraint solver, like Alloy Analyzer! I created the following model (took me half an hour, so no comments or too much thought about it).

Alloy Analyzer came up with a solution in 3 seconds, on the dual core 2GB RAM opteron server running linux!

The solution is the following one:

symbol= { (Cell_0 Blade_0) (Cell_1 Blade_0) (Cell_2 Blade_0) (Cell_3 Blade_0) (Cell_4 Fi_0) (Cell_5 Fi_0) (Cell_6 Fi_0) (Cell_7 Fi_0) (Cell_8 Cross_0) (Cell_9 Cross_0) (Cell_10 Cross_0) (Cell_11 Cross_0) (Cell_12 Star_0) (Cell_13 Star_0) (Cell_14 Star_0) (Cell_15 Star_0) }

rowIndex = { (Cell_0 One_0) (Cell_1 Two_0) (Cell_2 Three_0) (Cell_3 Four_0) (Cell_4 One_0) (Cell_5 Two_0) (Cell_6 Three_0) (Cell_7 Four_0) (Cell_8 One_0) (Cell_9 Two_0) (Cell_10 Three_0) (Cell_11 Four_0) (Cell_12 One_0) (Cell_13 Two_0) (Cell_14 Three_0) (Cell_15 Four_0) }

columnIndex = { (Cell_0 One_0) (Cell_1 Four_0) (Cell_2 Three_0) (Cell_3 Two_0) (Cell_4 Four_0) (Cell_5 Three_0) (Cell_6 Two_0) (Cell_7 One_0) (Cell_8 Three_0) (Cell_9 Two_0) (Cell_10 One_0) (Cell_11 Four_0) (Cell_12 Two_0) (Cell_13 One_0) (Cell_14 Four_0) (Cell_15 Three_0) }

It is quite straightforward! The symbol of Cell_0 is Blade, its row is One and column One. The symbol of Cell_1 is Blade again, he row is Two and Column Four etc.

The symbol names are not related to the movie or book symbol names. In my model Blade is the pyramid like shape, Fi is the Greek letter fi, Cross is the symbol that looks like a cross and Star is the symbol that looks like a star. I know that I spent half an hour to solve a problem that would have taken me around 10 minutes to solve manually, but as a proper nerd I prefer to use my (few) grey cells to think how to use a computer to solve a problem for me, instead of solving the problem myself.

Well.. that’s it! I don’t want to spend more than 1 hour on this!

There are a couple of blogs with solutions to the puzzles.
Links to solutions:

UPDATE: I used the model on my P4 running @ 2.8G with 712 MB ram and took AA 23 seconds to solve the problem. Not bad at all! But for bigger problems the state space will be increased by too much. Looks like an AI technique should be used to find a solution.