Arteraktiv » Agil

Introduction to JAVA threads part 1

Agil — Thu, 31 Mar 2011 02:52:33 +0000

Simple java thread example retrieved from IBM developerWorks

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public class TwoThreads {
public static class Thread1 extends Thread {
public void run() {
System.out.println("A");
System.out.println("B");
}
}

public static class Thread2 extends Thread {
public void run() {
System.out.println("1");
System.out.println("2");
}
}

public static void main(String[] args) {
new Thread1().start();
new Thread2().start();
}
}

We have no idea in what order the lines will execute, except that “1″ will be printed before “2″ and “A” before “B.” The output could be any one of the following:

1 2 A B
1 A 2 B
1 A B 2
A 1 2 B
A 1 B 2
A B 1 2

Not only may the results vary from machine to machine, but running the same program multiple times on the same machine may produce different results. Never assume one thread will do something before another thread does, unless you’ve used synchronization to force a specific ordering of execution.

to be continued….

div in a form or mixing form with div [HTML]

Agil — Wed, 09 Feb 2011 21:03:14 +0000

I thought I cant mix between form tag and div tag, I’m talking about HTML. In a basic HTML explanation I thought form tag cant be mixed with other tag than form tag itself. Here’s example of form tag from w3c

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<form action="form_action.asp" method="get">
First name: <input name="fname" type="text" />

Last name: <input name="lname" type="text" />

<input type="submit" value="Submit" />
</form>

But I come across to this theme and realize its’ form theme doesn’t include a form tag, how could it be…
Where I could place action page even the form tag doesn’t included. So it’s easy we just need to warp all form element, with a form tag. here’s an example of div tag in a form tag

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<form>
<div class="grid_16">
<h2>Submit News Article</h2>
Something went wronk.</div>
<div class="grid_5">
<label for="title">Title <small>Must contain alpha-numeric characters.</small></label>
<input name="title" type="text" /></div>
<div class="grid_5">
<label for="title">Slug <small>Must contain alpha-numeric characters.</small></label>
<input name="title" type="text" /></div>
<div class="grid_6">
<label for="title">Category</label>
<select>
<option>Draft</option>
<option>Published</option>
<option>Private</option>
</select></div>
<div class="grid_16">
<label>Summary <small>Will be displayed in search engine results.</small></label>
<textarea></textarea></div>
<div class="grid_16">
<label>Article <small>Markdown Syntax.</small></label>
<textarea class="big"></textarea>
<input type="reset" value="Reset" />
<input type="submit" value="Post" /></div>
</form>

I just need to add action attribute and method attribute if necessaries

debugging php in quick and lightweight environment

Agil — Tue, 08 Feb 2011 17:02:09 +0000

Sometimes the debugger, xdebug, zend debugger, aren’t working. So instead debugging, we just spend time to debug the debugger itself.
To debug quickly in php we just need to call exit function with variable or any parameter we want. so the script stop and displaying what exactly in the exit parameter.
Example, suppose you want to know what happen with an array so you just type

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include_once 'some_include.php';

exit("What's this : ".print_r($arr));
?>

that’s all for today.

Simple PHP MySQL Blog Example

Agil — Thu, 21 Oct 2010 20:26:41 +0000

OK, this is just one of many PHP ad MySQL implementation, it is my course which I’m taking actually. So in this post is what my lecturer gave to us. Lets dive into our first step. OK, no more talk, lets practice.

Developing a web application based on PHP and MySQL as its database can be done by many tools, you can use EclipsePDT, Adobe® Dreamweaver®, Netbeans, and many more. We ‘ll not cover many PHP IDE feature, so we can focus on simplicity of this tutorial. To proceed to the next step we’ll use these tools:

Notepad++ (free text editor with php syntax highlighting)
SRWare (free web browser)
XAMPP 1.7.3 with PHP 5.3.1 and MySQL 5.1.41
This sample database

and now, we can try to cook from some PHP and MySQL,

Run your XAMPP, so apache(php web server) and MySQL server started.

Create a MySQL database, we named it simpleblog, and import the sample database, (If you need detail you can always ask by commenting below).
Prepare your web folder in xampp htdocs folder. We named it simpleblog.
Create MySQL connection file to connect PHP to MySQL. Open Notepad++, create new file, save as MysqlConn.php and save it inside simpleblog/lib folder(note: create lib folder inside simpleblog folder). Copy and paste the next code:
Set user, password, database name, match to your XAMPP setting.

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/* @created nov 10 2007 13:00
* @lastmodified
* @package
* @file obj/MysqlConn
* @desc extends class Connection
* support get single / multiple array
* - use getArrayAssoc / getArrayNum -> single data
* - use getDataAssoc / getDataNum -> mltiple data
* Assoc --> association array,
* Num --> numeric array
*
* copyright (c)2001 - 2007 arif laksito
*/
Class Connection {
var $host;
var $dbname;
var $user;
var $pass;
var $error;

function Connection() {
$this->host = 'localhost';
$this->dbname = 'simpleblog';
$this->user = 'root';
$this->pass = 'pass';
}

}

Class MysqlConn extends Connection {

var $db; // var db conn
var $str; // var statatement query
var $rst; // var result query

// constructor class
// assign variable connection
function MysqlConn() {
$this->Connection();
}

// open connection MsSQL DB
function openConnection() {
$this->db = mysql_connect($this->host,$this->user,$this->pass)
or die('connection error..');
mysql_select_db($this->dbname, $this->db)
or die('conect to db error..');
}

// execution query statement
function execute($str) {
$this->openConnection();
$this->str = $str;
if($this->rst = mysql_query($this->str, $this->db))
return true;
else{
die( 'sql error : '.mysql_error() );
return false;
}

$this->closeConnection();
}

// get array association from execution query
// return false on error
function getArrayAssoc() {
if($this->rst) {
if($this->row = mysql_fetch_array($this->rst, MYSQL_ASSOC))
return $this->row;
else
return false;
}
}

// get array numeric from execution query
// return false on error
function getArrayNum() {
if($this->rst) {
if($this->row = mysql_fetch_array($this->rst, MYSQL_NUM))
return $this->row;
else
return false;
}
}

// return data execution query on object data
// association object
function getObjectAssoc() {
if($this->rst) {
if($this->row = mysql_fetch_object($this->rst, MYSQL_ASSOC))
return $this->row;
else
return false;
}
}

// return data execution query on object data
// numeric object
function getObjectNum() {
if($this->rst) {
if($this->row = mysql_fetch_object($this->rst, MYSQL_NUM))
return $this->row;
else
return false;
}
}

// get set array from query result
// 'select' tipe query
// data --> association array
function getDataAssoc() {
$dataSet = array();
$i = 0;
while($data = $this->getArrayAssoc()) {
for($j=0; $j < $this->getNumFields(); $j++) {
$field = mysql_field_name($this->rst, $j);
$dataSet[$i][$field] = $data[$field];
}
$i++;
}

return $dataSet;

}

// data --> numeric array
function getDataNum() {
$dataSet = array();
$i = 0;
while($data = $this->getArrayNum()) {
for($j=0; $j < $this->getNumFields(); $j++) {
$dataSet[$i][$j] = $data[$j];
}
$i++;
}

return $dataSet;
}

function getNumRows() {
if($this->numRows = mysql_num_rows($this->rst))
return $this->numRows;
else
return false;
}

function getNumFields() {
if($this->numFields = mysql_num_fields($this->rst))
return $this->numFields;
else
return false;
}

function getAffRows() {
if(mysql_affected_rows()>0)
return true;
else
return false;
}

function closeConnection() {
mysql_close($this->db);
}
}
?>

Create index.php file inside simpleblog folder. copy and paste this:

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include_once 'lib/MysqlConn.php';
$sql = new MysqlConn();
$str = "SELECT beritaId, beritaTitle, beritaDetail, beritaTime, nama
from berita left join alumni On berita.beritaSender = alumni.id_alumni;";

$sql->execute($str);
$data = $sql->getDataAssoc();

print '

';

print_r($data);

print '

';

?>

Ok, for now lets try open the url, for me it will be http://localhost/simpleblog. It should be printing some words like this:

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Array

(

    [0] => Array

        (

            [beritaId] => 3

            [beritaTitle] => Internet Semakin diminati Wanita

            [beritaDetail] => San Fransisco, Kamis



Meskipun, pria dan wanita punya minat yang berbeda dalam menggunakan jaringan internet, lambat laun jumlahnya semakin seimbang.

Gambaran ...

For the next step lets make it more web look. Since this post don’t cover xhtml/css theme creating, so we’ll take some free theme from the net, for example freecsstemplates.org. We’ll take sparkling.
Copy unzipped theme to simpleblog folder. So the index.php and index.html which came from theme will be in the same folder.
Rename index.php to something else, index.old.php for example. Rename index.html to index.php. Copy and paste code below into your new index.php, before the html tag, you can paste it on line 13 :

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include_once 'lib/MysqlConn.php';

$sql = new MysqlConn();

$str = "SELECT beritaId, beritaTitle, beritaDetail, beritaTime, nama
from berita left join alumni On berita.beritaSender = alumni.id_alumni;";

$sql->execute($str);
$data = $sql->getDataAssoc();
?>

on line 58 change the code into this:

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foreach($data as $itm) {?>

echo "$itm[beritaTitle]";?>

echo "$itm[beritaTime]";?>Posted by echo "$itm[nama]";?>

echo "$itm[beritaDetail]";?>

} ?>

As you can see from the code above, the line which write the content of the post (post body) was line 7. The code just barely write all content body. We’ll change the code, so just some of the content will shown on the front page. Replace with this one:

1	echo substr($itm[beritaDetail], 0, strrpos(substr($itm[beritaDetail], 0, 300), " ")); ?>

When you click read more, still nothing happen yet. We’ll make one php file again to handle full post body.

JavaFX is dead?

Agil — Thu, 21 Oct 2010 17:44:07 +0000

According to this link Oracle has discontinued further development of JavaFX. Netbeans a free IDE from Oracle, later on its 7 version will not support javaFX, which will be release on march 2011 year based on their roadmap release.

metode numerik

Agil — Tue, 19 Oct 2010 17:43:23 +0000

coba gunakan search engine kesukaanmu untuk mencari kata dengan “metode numerik”, maka akan banyak link yang didapatkan, berikut ini salah satunya. Dari sumber tersebut terdapat pernyataan

Metode Numerik: Teknik dimana masalah matematika diformulasikan sedemikian rupa sehingga dapat diselesaikan oleh pengoperasian Aritmatika.

Metode numerik dapat menyelesaikan masalah matematika? Untuk lebih jelasnya silakan baca pdf tersebut. OK, sebenarnya, artikel ini dugunakan merupakan catatan penulis dalam mengikuti kuliah metode numerik.Dalam mata kuliah ini dibahas juga tentang matriks . Beberapa operasi dalam matriks yaitu operasi penjumlahan dan perkalian. Untuk lebih jelasnya bisa download dari sini.

Dalam mata kuliah ini biasanya menggunakan software simulasi matematika, software dengan kemampuan matematika tinggi, biasanya digunakan MATLAB yang untuk melihat harganya saja harus mendaftar terlebih dahulu, ukuran file instalasinya-pun besar(diatas 1GB). Namun di sini kami gunakan alternatifnya yaitu freemat, berukuran 20MB untuk versi di bawah tahun 2009 gratis, berlisensi GNU Public License ver 2. Perintah-perintah yang digunakan setahu saya sama(cimw), tapi mungkin tetap saja ada perbedaannya, tidak 100% sama semua.

OK, selamat mencoba.

Error preverifying class Preverification failed with error code 1

Agil — Sat, 21 Aug 2010 18:59:02 +0000

When I using both netbeans 6.7.1 and 6.9 to create some j2me based apps it’s stop compiling with the error code:

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Preverifying 2 file(s) into E:\Play_On\Java\MyLab\mobileApp\mFaraid3\build\preverified directory.
Error preverifying class mfaraid.faraidMIDlet
java/lang/VerifyError:
E:\Play_On\Java\MyLab\mobileApp\mFaraid3\nbproject\build-impl.xml:470: Preverification failed with error code 1.
BUILD FAILED (total time: 0 seconds)

So I began investigating which is land me on some links, here, here, and here. After a few days of figuring out solution, fortunately my apps built again successfully. It happens when I realize my apps use java native floating point library, and I setting it to run on CLDC 1.0 not CLDC 1.1 which is floating point supported by built-in library.

Here is checklist I try to solve this problem:

Try turning off obfuscation(still got same error).
Lowering obfuscation level (still got similar error).
Go to “Libraries & Resources” and uncheck “Netbeans MIDP Components”. as my apps was trying to use WaitingScreen but I canceled it, the netbeans not automatically uncheck the unused library. (still got similar error).
Checking library used by the apps and matching it to target platform configuration. it was using floating number and java.lang.Math class, and somehow I was unconsciously switching to CLDC 1.0 which’s not support floating number and java.lang.Math class. So I switch back to CLDC 1.1 MIDP 2.0, and it works.

Why netbeans error log not pointing to this matter anyway….?

Analisis Desain Sistem Informasi

Agil — Wed, 18 Aug 2010 18:12:40 +0000

Analisis -> Desain/Logical Design -> Coding/Physical Design.

Salah satu process model ialah, flowchart, yaitu process model untuk sebuah program.
DFD, data flow diagram, 99% sama dengan use case diagaram dari kelompok use case diagram.
External entity dalam DFD dalam use case biasa disebut actor.
Internal entity dalam DFD ialah database, SQL misalnya, data yang diambil dari dalam.

langkah-langkah membuat DFD :

Sebelumnya pastikan bahan-bahan seperti requirments telah disiapkan, sehingga kita tinggal mengolah requirments menjadi DFD siap saji.

Buatlah context diagram, hanya terdiri dari satu proses.
Jabarkan context diagram menjadi DFD level 0 (nol).
berikan nomor pada tiap proses, internal entity, dan external entity.
Jabarkan lagi menjadi DFD level 1.
Terus jabarkan DFD kelevel berikutnya sesuai kebutuhan.
DFD telah siap saji.

Di dalam rangkaian membuat sistem informasi, aplikasi, program, apps. setelah membuat DFD kita dapat mengolah DFD tersebut untuk menghasilkan kamus data yang kemudian bisa kita olah melalui normalisasi untuk menjadi ERD, yang pada akhirnya ERD tersebut dapat kita olah untuk menjadi struktur database.

Dari DFD dan database yang telah ada mungkin(pengetahuan saya baru sampai sini) kita bisa membuat flowchart dari tiap-tiap proses yang ada pada DFD level terakhir. Dari situ coding bisa dilakukan. namun sebelumnya teliti lagi DFD dan database siapa tahu ada kekurangan.

Menggunakan MovieClip dari library pada adobe flash cs4

Agil — Tue, 04 May 2010 00:16:03 +0000

Menggunakan asset dari library ke dalam stage pada saat runtime tentunya kita dibutuhkan sedikit actionscript. Kita akan mencoba membuat sebuah contoh untuk memanggil asset(baik itu movieclip, button, atau lainnya) dari library ke dalam stage dalam sebuah aplikasi flash sederhana.

Alat yang perlu dipersiapkan:

Adobe Flash versi CS3/CS4/CS5

Pertama-tama kita buat new document pada flash, pilih yang actionscript 3.0. Kemudian buat sebuah kotak hijau(yang akan dijadikan movieclip nantinya) dan sebuah button, berikan nama untuk button misal tombol. Select pada kotak hijau, kemudian klik kanan, pilih Convert to symbol, maka akan muncul dialog seperti di bawah ini (tekan advance jika belum muncul seprti di bawah ini). gantilah nama simbol dengan nama hijau misalnya, untuk menjadikan sebuah movieClip yang bisa diambil dari library pada runtime maka berikan centang pada pilihan export for actionscript, kemudian ganti nama Class menjadi Hijau misalnya (nama Class boleh berbeda dengan nama symbol ). Kira-kira seperti ini skrinsutnya(screenshot):

Seperti inilah kira-kira tampilan export to symbol

Pilih OK.

Setelah itu hapus movieclip yg ada di stage. berikan kode ini pada timeline:

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var nampak:Boolean=false;
var hijau_mc:Hijau = new Hijau();

tombol.addEventListener(MouseEvent.CLICK, handleClick);

function handleClick(e:MouseEvent):void {
if (! nampak) {
addChild(hijau_mc);
nampak=true;
} else {
removeChild(hijau_mc);
nampak=false;
}
}

Ctrl+Enter.

ada yang blum jelas. atau kurang setuju silakan menulis comment

XMPP flex 4 client sample

Agil — Sun, 02 May 2010 19:15:08 +0000

XMPP is an open standard protocol for instant message service. Actionscript 3.0 is a client side programming language. In this post we will try to make an xmpp chat client which not utilizes TLS connection, so we will able to connect to some servers providing non-TLS connection such as jabber.org, igniterealtime.org, etc. To begin we need some requirement to use:

XIFF, an xmpp library for actionscript 3.0
Openfire, an xmpp server (for testing your app locally)
Flash Builder 4 or any equivalent flex editor (FlashDevelop, netbeans+flexplugin)
This sample project, right click to view source

You can see the result here.

Comment, question, and suggestion are welcome.