Information Technology Tips

IPv4 Address to Long I have written code for converting dotted IPv4 IP address to BigInteger value in Java. This code is inspired by PHP's ip2long function. The function is useful when you compare IP addresses based on numeric magnitude relationship. Java Code public static BigInteger dotIPv4_to_BigInteger(String dottedIP) { String[] addrArray = dottedIP.split("\\."); BigInteger num = BigInteger.ZERO; BigInteger block = BigInteger.valueOf(256); for (int i = 0; i < addrArray.length; i++) { int power = 3-i; BigInteger value = BigInteger.valueOf(Integer.parseInt(addrArray[i]) % 256); value = value.multiply(block.pow(power)); num = num.add(value); } return num; } Here is an example. // following code output "2071690107" System.out.println(dotIPv4_to_BigInteger("123.123.123.123"));

Introduction In this post, I'm going to write about "Why & How to measure your code of software project. And improve it." I am going to mainly write about this topic from the static code analysis point. Why Measure? There are number of reasons to measure your code. For me especially following reasons (or intentions). Daily Health Check Keep code base clean See impact on entire code base by your code change Detect problems as soon as possible Feel improvement! Let every team members show what happens Monitor test result status Follow coding standard Especially in team based software development, a lot of people change code for different task. And each developer is hard to know what each developer change the code for what purpose. If the source code measurement is public for everyone, it helps everyone to know affect of entire project which the other developers make. What to Measure? There are a lot of measurement is proposed but from static

Symfony 1.4 Action plus View Rendering PHPUnit Test I wrote test case for executing action and rendering view test. However testing action plus final rendering result is quite not easy because you need to understand how Symfony 1.4 framework handles web request and rendering model to view internally. I have investigated in the framework a bit and found a solution. Please see the test case example in the next section. Code <?php $basePath = dirname(__FILE__).'/../../../../apps/your_app_name/modules/'; $modulePaths = glob($basePath.'*', GLOB_ONLYDIR); foreach($modulePaths as $modulePath) { require_once $modulePath.'/actions/actions.class.php'; } class ActionsTest extends PHPUnit_Framework_TestCase { public function testActions() { // create stub web request $request = $this->createStubfWebRequest(); // action you would like to test. // you should pass module and action name refelctively $actions = new TargetActions($this

Motivation: Visualize 2 Dimensional Data with Lightweight Way I wrote small java program for calculating Jaccard Similarity among source code in this post . And map into them 2 dimensional map using Multi Dimensional Scaling technique. I have used MDSJ – Multidimensional Scaling for Java . (By the way the library is quite simple and meet my requirement perfectly!! Excellent!!)> Next step is how to visualize the bunch of 2 dimensional (x,y) coordinate data so that human can easily understand. Of course, I am good at Java, I can write some code for visualize data in Java using Swing or Java FX etc. But it's not lightweight way. So, I decided to use HTML5 Canvas + Javascript. Viewer: Html5 Canvas + Javascript The features of the Data Viewer are: Visualize CSV data Expected 3 columns without header row: name

Reusable Code for Execute Any DB Access Code in Transaction In this post, I will show you highly reusable utility code for wrapping and executing original db access code in transaction. Anyway let's show you the code. function executeInTransaction(callable $func) { $conn = new PDO(SERVER_NAME, USERNAME, PASSWORD, DBNAME); try { $conn->beginTransaction(); $func($conn); $conn->commit(); } catch (Exception $ex) { $conn->rollBack(); throw $ex; } } Oh, how to use? You just simply passing your core DB access code as the callable $func argument. Okay, let me show you example in next section. Example Usage First, assume you have following 2 methods for inserting data to DB. CONST SERVER_NAME = 'localhost'; CONST USERNAME = "username"; CONST PASSWORD = "password"; CONS