a developer's perspective

Sample Calculator GUI in Java Swing

2007-06-16T03:22:00.006+07:00

Recently, I was giving my 1st-year IT students several Swing GUI exercises on OOP with Java lab sessions. One of the exercises was to create a simplified Calculator GUI that looks like the Calculator on standard Windows OS. The objective of the exercise was to make the students familiar with the basic Swing layout managers (note: I haven't thought them GridBag, Spring, or JGoodies Forms layouts),

Freedom Writer

2007-05-20T08:34:00.000+07:00

I've just finished watching Freedom Writers. It's been a long time since I've watched anything with that quality. Not just because I am a lecturer myself, but even before I became one, I still would have thought the same. Simply put, the movie is awesome.Through the 120+ minutes, my emotion was taken captive by the storyline that I learned a lot from the movie. I have pretty much the same ideals

Encrypted CVS Repository

2006-01-20T07:52:00.000+07:00

We currently have a client that's very concerned with Information Security. It's a multinational company, and we're dealing with its Indonesian subsidiary. Its head office periodically performs scans throughout their subsidiaries' networks across the world, and identifies any possible information security breach. The problem is the network scans prove that when someone has read-access to the CVS

Reading a character from the Console

2006-01-09T07:02:00.002+07:00

Reading a character from the Console should not be a problem. I hadn't had that problem using C++ back in the college days, but somehow it's not that easy in Java. I have never found the need for it myself, but someone at the local JUG mailing list apparently needs it.Java has always have the problem of reading a character from the Console, without buffering and echoing back to the Console. This

Understanding Fluent Interface

2006-01-02T09:08:00.003+07:00

After reading Martin Fowler's post regarding fluent interface, I try to write small trivial implementations to understand the concept. Here are the common interfaces of Customer, Order & OrderLine classes, as required by Martin's "makeNormal" method:Customer +addOrder(Order): voidOrder +addLine(OrderLine): void +setRush(boolean): voidOrderLine +OrderLine(int, Product) +setSkippable(boolean):

Getting a credit card

2005-12-15T06:29:00.000+07:00

I've always been a no-credit guy. I don't like to ask for any loan for any purpose. That's my principle since I was a kid, perhaps parts of what my dad has taught me. Now, I've created and/or implemented more than 2 automotive loan application systems (one of them is a product of my employer), and since I know exactly the formula they use for the loan installment payments, it further discourages

A better work in the next 5 years?

2005-12-13T05:46:00.000+07:00

Since highschool, I always believe that I need to keep on learning in order to stay alive. The same with my line of work. I'm trying to keep myself up-to-date with what might be a valid source of income for the next years to come. I've been trying to keep myself to think that I need to be able to find myself a good, if not better, work in the next 5 years.My current choice is a Bachelor Degree in

Today's Reading - 12 Dec 05

2005-12-12T07:15:00.002+07:00

Iranian blogger is rejected to visit the US due to his blog contents.His lesson teaches us to be careful in saying our political views, to be careful NOT to bring up unnecessary information about our personality when we're crossing any border, and also to think again whether being searchable by Google is a good thing or not.Erik Thauvin is receiving e-mails that says he has Java Trademark

recursive directory search

2005-05-17T20:41:00.000+07:00

A friend of mine just asked me how to write a Java code that will perform a search on a directory and all of its subdirectories (recursively) matching a given file suffix, for example, all JSP files. I remembered that I was doing a small project a few months ago that had to deal with this functionality. And, I also remembered that it was a simple thing to do. So I went to the jakarta-commons

String bug

2005-04-28T20:01:00.000+07:00

Apparently, there is a bug in the Sun JDK 1.4.2 or lower implementation of java.lang.String. This bug has been identified as 4310930, 4546734, 4637640, 4724129 in Sun's Bug Database. I've come across this bug while reading Charles Miller's post, when he was having trouble with the OutOfMemoryError in his JDBC code. Please download this source code to see what I'm talking about. Try to run the

Petals around the Rose Puzzle

2005-04-14T12:18:00.000+07:00

A friend of mine send me a link to the Petals around the Rose Puzzle. It's essentially a simulation of rolling 5 dice at the same time, then guess what is the number of Petals around the Rose. It's quite fun actually to guess them. I've had 16 tries (approx. 15 mins) before finding my solution to the problem. The solution has been proven within the next 30 successfull tries. Try them out for

Immutable classes

2005-04-11T16:14:00.000+07:00

Here's my opinion on immutable classes, answering Bayu's comment which asks for an explanation on when and how to implement them. Making a Java class immutable usually make the overall design of a system slightly better compared to making all Java classes mutable. Whenever possible, making such class immutable will make it easier to be implemented and maintained. First, don't provide any

VB6 no longer supported

2005-04-04T11:55:00.000+07:00

Since last Friday, 01-Apr-2005, Microsoft no longer supports VB6. Instead, VB6 will only be supported for another 3 years in a period called extended phase. After 01-Apr-2008, VB6 will no longer be supported. During extended phase, all supports & updates will be charged. All online supports will be terminated during the extended phase. And, no new license can be bought for VB6. For a complete

List Pagination (Continued)

2005-03-31T10:28:00.000+07:00

To answer Josh's comment on why the implementation of list pagination is quite long, here's a brief background. This post may be beneficial to Java/OOP newbie, in terms of thinking in an OOP and working in a TDD (Test Driven Development) way. It's all started with the modeling of what a Page object may look like. Well, it has to have a page number and the contents (list of records) itself. Then,

List Pagination (Value List Holder)

2005-03-30T16:11:00.000+07:00

Someone at our JUG Indonesia has a problem with displaying a List in a number of pages (aka List Pagination). This problem can be solved using the Value List Holder design pattern. I'm attaching my solution to the problem for him (or anyone who may found this useful), so that it'd be easier for him to have a look and discuss.This solution can be used for both web application and non-web

migrating from WebLogic in Linux to OC4J in XP

2005-03-17T17:34:00.000+07:00

A couple of weeks ago I was trying to resurrect a 3 yr-old project, implemented using WebLogic 6 in Linux, into a working web application using OC4J 10gAS in Windows XP. Here are some notes I made during the process, which might help anyone doing or planning to do the same: 1. Do not rely on vendor specific deployment descriptor. If you have to, use the same name everywhere. Back in 2001

using JSPWiki

2005-03-16T16:50:00.000+07:00

Over the last two months, I've been busy doing many improvements within the company, with one of them is creating a company Wiki to store our lessons learned through the years. After examining through a number of Java Wiki Engine, my final decision was to go with JSPWiki. Compared against XWiki, it's much easier to install and to maintain. It's very light, requires no RDBMS, and almost anyone

double vs. BigDecimal

2005-01-31T11:17:00.000+07:00

Apart of continuous education and code reviews, there are still some Java codes I've found among my colleagues which are created without giving much thought on the floating-point arithmetic in Java. This is contradictory to the fact that a consistent floating-point arithmetic is essential for any financial applications.Try and run the following code snippet: public static void main (String[]

analyzing the Requirement Gathering process

2005-01-12T14:10:00.000+07:00

When I tried to analyze what's the best suited way for our company to perform the Requirement Gathering process, I've come across to the following resources: - Wikipedia on Requirement Gathering - Requirement Analysis, an article by Karanjeet Bali Both resources have helped me a lot in performing with the definition of the Requirement Gathering process, the challenge of effective Requirement

Goals for Year 2005

2005-01-05T17:40:00.000+07:00

I'm currently trying to define a workplan for the year 2005, where I could bring the company to a higher level in terms of performing software development tasks. There are a lot of things that will need improvements, both on the technical aspect and process/methodologies. Can anyone point me out to a good resource of where to find the best resources for SDLC, processes, and methodologies? Four

tsunami video

2004-12-30T15:06:00.000+07:00

Just thought I share what I found in Google while searching for the Tsunami video.. There is actually a better video which was aired last night on national TV, about a whole family in Aceh (Indonesia) who have to stay in the second level of their house watching nothing but water and ruins of the neighbouring houses surrounding their house. The numbers are increasing, it's more than 27,000+

Carcassonne Game Session Report 17-Dec-04

2004-12-29T14:36:00.000+07:00

A couple Friday ago, I had a chance to gather some of my friends to play some board game at my place. The game we played that night was Carcassonne. If you're not familiar with the game, you can check it out on FunAgainGames or BoardGameGeek. It was a good gaming session though I expect more people would be able to join the session. Anyway, following is the session report:Carcassonne Session

tsunami

2004-12-28T09:18:00.000+07:00

South Asia & South East Asia have just been hit by a great tsunami caused by the 5th largest earthquake since 1900, causing 24,000+ people killed, many thousands missing & millions injured. Indonesia is no exception, the death toll is reaching 4,000+ already. Search Google News for "Tsunami" or "Tsunami Indonesia".. Please help in any way that you can..

Query by Example or by Criteria

2004-12-24T18:38:00.000+07:00

Again, misconception on ORM. A colleague of mine tries to query the database to find a record based on a field of the same table. He tries to use a query by example (a feature in Toplink which allows us to find the matching persistent object(s) if you provide the sample instance). I don't know whether this feature exists in other ORM technologies, e.g. Hibernate, but it's becoming quite handy.

POI for Excel parser

2004-12-13T09:39:00.000+07:00

It's been over a month since my last post. Sorry guys. It's been busy at work, and no internet connection. I had a nice two weeks vacation though, and it was fun.. :D Anyway, during the vacation, I happened to help a friend of mine finish up his project. I helped him to create a component to parse resume documents. These documents can be in Word, Excel, HTML or plain text. He wanted me to be