Host file in XP

c:\windows\system32\drivers\etc\hosts

ஈழம் மௌனத்தின் வலி

Google Wave

Google Wave is an online tool for real-time communication and collaboration. A wave can be both a conversation and a document where people can discuss and work together using richly formatted text, photos, videos, maps, and more.

http://wave.google.com/

Currently new accounts are allowed with invitations.

Go - New Programming Language from Google

Tutorials:
http://golang.org/doc/go_tutorial.html

Singletons are Global state: Use wisely

We had an opportunity to write unit test cases for some legacy code and it was tough job. Find it very difficult especially when so much singletons are used on code base.

We should really use it only when its required. The following article forces that.

Refer:
http://www.ibm.com/developerworks/webservices/library/co-single.html

Google has singleton detector for sometime now, that can be very useful if you need to analyze the code base without source code.

Refer:
http://code.google.com/p/google-singleton-detector/

Law of Demeter and violations.

Law of Demeter - "Only talk to your immediate friends"
An object should avoid invoking methods of a member object returned by another method. In Java,the law can be stated simply as "use only one dot". That is, the code "a.b.Method()" breaks the law where "a.Method()" does not.

Violations:
With the SOA applications rising up these days, its very difficult to draw a line to what extend one can violate this law.

One way to create appropriate facades to wrap the internal extensions, however it just looks like for the sack of the (LoD) Law of Demeter and in fact slows one down on development.

Lot of third party libraries does not seem to care about the principle at all.Everyday we use these libraries,needless to say with lot of dots,and when we get "NullPointerException", the deguggin goes crazy.

We should realize the value of LoD, at least from unit testing perspective and its very hard to test the piece of the code that violates the LoD to larger extend.

Strongly feel, developers or API Architects should take LoD into account when they design plugin/libraries.

Challenge your Math Skill

Visit http://mathschallenge.net/ and try to solve a problem or two.

Happy solving!

Are you ready to prove your programming expertise?

Following are few of the sites which offer wide variety of challenges for programmers of most of the languages and reward them.

Code Golf

When: Ongoing, new challenges posted sporadically

Languages: Perl, PHP, Python, Ruby

How it works: Based on the original perl golf, Code Golf allows you to show off your code-fu by solving coding problems using the least number of keystrokes. The challenges cover a nice mix of topics; example challenges are 99 Bottles of Beer, Tower of Hanoi, The Game of Life, and converting Roman numerals to base 10 integers.

How to win: Submit your code, and if it passes the challenge test cases, your entry is scored according to the number of characters. Win bragging rights by appearing on the overall leader board or the leader board for each problem.

UVa

When: New contests every month

Languages: C, Java, C++, Pascal

How it works: Each contest consists of anywhere between 3 and 10 problems. The problem sets demand quick thinking and a good computer science background with solid knowledge of algorithms, data structures, and mathematics. Common themes are palindromes, primes, and graphs. Check out the extensive contest archives for practice.

How to win: Contests are timed and usually last several hours, so have some coffee and brain food nearby. Submit code for each problem to the automatic tester when it’s finished. Contestants are ranked by the number of correct solutions and ties broken by the time taken to complete the challenge.

Mindcipher

When: Ongoing

Languages: Logic

How it works: Mindcipher is a social repository of the world’s greatest brain teasers, logical puzzles and mental challenges. No programming required, just logic and common sense. Some of the problems are taken from Google and Microsoft interviews so brush up your interview skills while having some fun. Categories of brain teasers are mathematics, physics, at the campfire, logical, riddles, lateral thinking, optical illusions, and general. Each puzzle is ranked according to difficulty and members can vote up favorite puzzles.

How to win: Answers are provided for each brain teaser, so there isn’t really any winning involved.


Project Euler

When: Ongoing

Languages: All languages

How it works: Each problem is designed to be solved by some combination of mathematical insight and algorithm design. Problems build on one another, getting progressively harder, so its a great way to keep your math skills fresh. After solving a problem you are given access to the forum containing algorithm discussion and solutions in a wide variety of languages, so Project Euler is a nice way to learn a new language.

How to win: Submit correct answers to the most recent 25 problems to earn a spot on the venerable Eulerians list. Or solve more than 200 puzzles to reach level 5.


TopCoder

When: Weekly rated competitions, and practice rooms that are always open

Languages: Java, C++, C#, Visual Basic

How it works: In TopCoder’s algorithm competitions, you have a set amount of time to complete the problem set (usually an hour). Code is normally developed inside TopCoder; there are multiple plugins that provide an IDE within your browser.

TC also holds “competitions” in bug fixing and component design, development, and assembly. These competitions are actually work developed on a speculative basis for companies who have outsourced development to TC, with “prizes” given to work with the best ratings.

How to win: For the algorithm competitions, develop, test, and submit solutions to the 3 problems in the set during the submission widow. After a 5 minute intermission you can view competitors’ code and challenge it by giving a test case that you believe will break the submission. Scoring is based on problem difficulty, time to complete the problem, results of the challenge round, and results of automated testing.


The International Obfuscated C Code Contest

When: Yearly (but currently on hiatus after 19 competitions)

Languages: C

How it works: Submit your most obfuscated ANSI C code. Each contest has a list of rules concerning code size, the build process, compile dependencies, etc. However, legal abuse of the rules is somewhat encouraged. Winners from previous years have all used nefariously tricky obfuscation.

How to win: Submissions are judged by a panel of judges based on how obfuscated the code is. Originality is important in both the type of obfuscation used and the purpose of the code.


Enjoy Programming!!!

Enchanting Tamilnadu -

Recently Tamilnadu Tourism Development Corporation lead by Dr.V.Irai Anbu, IAS,
revamped their services to improve tourism in the state.

Next time before planning any vacation, visit http://www.tamilnadutourism.org/

அறிய பொக்கிஷங்கள் அடங்கிய களைஞ்சியம் நம் தமிழகம் என்பதை நினைவூட்டும் வகையில், பயனுள்ள தகவல்களை இத்தளத்தில் காணலாம்.

TTDC-இன் பணி சிறக்க வாழ்த்துக்கள்.

Browserscope - Browser Profiler

Open source project that tests and compare your browser performance with rest of available browser on the market.

Backed by Google,this is very helpful on profiling your browser and application.

More @ www.browserscope.org

How to develop iPhone apps?

A legal iPhone application can only be developed on Apple hardware. ie, Mac systems.

The applications are developed on Apple OS [OS 10.5 or later] using iPhone Sofware Development Kit.

One has to register as 'iPhone' app developer through enrolling iPhone Developer Program [Standard Program $99 and Enterprise Program $299 as on today] in order to get the iPhone/iPod Touch - SDK.

Successful applications can be sent to Apple for approval and there by getting into Apple Store before reaching out to the customers.

Few people hack these steps to develop iPhone app using windows, however that cannot get through via App Store and will never be legal.

Lot of rources to guide through step by step creation of iPhone app can be found at developer central at Apple site.


http://developer.apple.com/iphone

Leadership and Vision

GigaOM - Intresting current affairs on Tech

http://gigaom.com/

Windows command prompt Tips

Useful tips that can be used on windows command prompt.

1. F1 retypes the previous command one character at a time
2. F2 brings up a dialog and asks "Enter the char to copy up to:"
3. F3 retypes the last command in full
4. F4 brings up a dialog and asks "Enter char to delete up to:"
5. F5 as for F3
6. F6 Print EOF character (Ctrl+Z)
7. F7 brings up a dialog of all the recent command history
8. F8 brings up each of the most recent commands, one at a time
9. F9 brings up a dialog and asks "Enter command number:"

Great Tamils

Silver Bullet - Time Travelling Debugger

Full video courses from leading universities.

Worth a visit!

http://www.academicearth.org/

முன்னணி கல்வி நிறுவனங்களின் இலவச பாடசாலை.

பல்வேறு துறைகளை பற்றிய அறிஞர்களின் உரைகளின் படத்தொகுப்பு.

http://www.academicearth.org/

Change Column from Varchar2 to CLOB


SQL>alter table test_table add clob_column CLOB;

Table altered.

SQL> update test_table set clob_column = current_varchar_column;

xx rows updated.

SQL> alter table test_table drop column current_varchar_column;

Table altered.

SQL> alter table test_table rename column clob_column to current_varchar_column;

Table altered.


Java4iPhone

Product Intro - List2Shop - Manage your shopping checklist!

Did you ever wish, you had a shopping checklist handy every time you went to a grocery store or a mall? Ever thought of a tool to keep a tab on weekly shopping needs?

Refer:

http://www.list2shop.com/shopping/

Speed Up Your JavaScript

JavaScript - Higher-Order Functions - First Class Functions

The main difference between a mathematical function[or pure functional language function] and the notion of a "function" used in imperative programming[widely spread industrily used programming languages] is that imperative functions [or methods] can have side effects, changing the value of already calculated computations, i.e. the same language expression can result in different values at different times depending on the state of the executing program.

Conversely, in functional code, the output value of a function depends only on the arguments that are input to the function, so calling a function f twice with the same value for an argument x will produce the same result f(x) both times.

Functions are higher-order when they can take other functions as arguments, and return them as results. (Operators in mathematics, such as the differential operator d / dx that produces the derivative in calculus when applied to a function f, are examples of this.)

Higher-order functions enable currying, a technique in which a function is applied to its arguments one at a time, with each application returning a new function that accepts the next argument.

Higher order functions in Java script.

sayHello = function(f1){

alert(f1('Power Of JS')('Easy Higher Order Functions!'));

};

sayHello(function(prefix){

getPrefix = function(){

return prefix;

};

return function(a){

return getPrefix()+' - ' +a;

}; } );

Thoughts on Keyboard Design

From the ages of personal/business computing machine and Notebook/laptop designs, I guess keyboard is one of the most neglected part. Not sure how many manufacturers ever really given any thought on that.

At least customized laptops can be provided with options of keyboards. You have lots of choices on other aspects of laptop, then why not we have to bear with same-old fashined keyboard alone?

If the designer really run out of any changes....here my two pennies..

* CAPS LOCK - Its carried from typewriter design. How many people require ALL CAPS typing on a laptop?? We have sophisticated word processors these days which can easily do the job. Why the hell we still need this?

* NUM LOCK - I really forget when either me or my friends [ppl with computers for 20 hrs a day] last time use this key?

* Functional Keys - Albeit key board savvvy techies like keyboard navigations..but lots of functions can be programmed without functional keys.. can we save that space for other keys?

Lets hope, these matters for those who matter on laptop designs.

நம் பணி!

அறிவியலின் மகளாய் பிறந்து, அமெரிக்காவில் வளர்ந்து இன்று நம் பட்டி தொட்டி எங்கும் நீக்கமற நிறைந்திருந்து, மன பலத்தையும் , அறிவையும், உழைப்பையும் மட்டும் நம்பியிருந்த பலகோடி இளம் நம்பி நங்கைகளுக்கு, தொழிலாய் அமைந்து பொன்னான வாழ்வளித்திருக்கும் கணினிக்கு நமது வாழ்நாள் நன்றி!

கணினியை என்னை போன்று தொழிலுக்காகவோ, அல்லது பொது-சுய உதவிக்காகவோ பயன்படுத்தும் எல்லா கைகளுக்கும் வணக்கம்.

ஒருநாள் ஆய்வகங்களிலும், பணம் புரளும் அலுவகங்களிலும் மட்டுமே ஆராதிக்கப்பட்டவள், இன்று நம்மூர் மருந்து கடை தொட்டு, பீடி சிகரட் கடை வரை வலை விரித்திருப்பது நிதர்சனம்.

இவ்வளவு அரிய வளர்ச்சியை சீரமைக்க, மேம்படுத்த, கண்காணிக்க, பரவலாக்க, எத்துணையோ கைகள் உழைக்கின்றன.

கணினி தொழிலும், கட்டிட வேலை போன்று பரவலானதலும், ஆங்கில அறிவை பெற்ற ஒரு சிலரே செய்ய முடியும் என்கிற ஆணவத்தாலும், இத் துறையை நாடும் பல போலிகள் பெருகிவிட்டன.

எதோ ஒரு, டுடோரியல் சென்டெரில் ஆறு மாதம் படித்துவிட்டு, ஒன்றோ இரண்டோ சான்றிதழ்களை பெற்று கொண்டு , தானும் ஒரு Sofware Engineer என்று சொல்லிக்கொண்டு எத்துணையோ வேடதாரிகள் பிழைத்துக்கொண்டு இருக்கிறார்கள்.

இத்துறையின் பொறுப்பு, நான்கு வரி code, கூகிள்-இருந்து சுட்டு, copy paste செய்துவிட்டு QA வை கையில் போட்டுகொண்டு - Defects free Delivery - செய்வதோடு மட்டும் முடிந்துவிடுவதில்லை.

இதையும் தாண்டி, இதன் அடிப்படையை புரிந்து, இவள் அழகை, பெருமையை உண்மையாய் ரசித்து, இன்னும் ஒரு படி மேல் கொண்டு செல்ல துடிக்கும் ஒரு சில நெஞ்சங்களும் இருக்கத்தான் செய்கின்றன.

இத்துறையின் பொறுப்பு ஒரு நல்லாசிரியரை போன்றது. ஒரு ஆசானின் தவறால் எப்படி ஒரு இளம் சமுதாயமே பாதிக்கபடுகிறதோ, அங்ஙனம் பெருகிவரும் சாப்ட்வேர் கருப்பு ஆடுகளால், கணினியின் நலன் மட்டுமின்றி, நம் நாட்டின் நாளைய வளர்ச்சியும் கூட பாதிக்கபடலாம்.

ஆகையால், ஒவ்வொரு கணினி வல்லுனரும் - குறிப்பாக இந்திய கணினி வல்லுனர்கள்-
தமது பொறுப்புணர்ந்து, எவ்வழியில் இத்துறையில் நுழைந்திருந்தாலும், இனிமேலாவது ,இதன் அருமை உணர்ந்து, செம்மையான வளர்ச்சிக்கான வழிகளை சிந்தித்து செயல் ஆற்றுவோமாக.

இப் பொறுப்பே இப்பதிவை தொடங்குவதற்கான உந்து சக்தி. பின்வரும் நோக்கங்களுக்கான நமது சிந்தனைகளை இங்கே பகிர்வோமாக.

* கலையாக பயிலுதல் & பயிற்றுவித்தல்
* நுணுக்கங்கள்
* திட்ட மேலாண்மை & செய்முறை
* நம்ம ஊர் பயன்படிற்கான கருவிகள்

இப்பதிவு, கணினியையும் அதன் பயன்பாட்டையும், அதன் வளர்ச்சியையும் ஆராதிப்பவர்களுக்கு காணிக்கை.

Dependency Injection with Guice

Guice (pronounced 'juice') is a lightweight dependency injection framework for Java 5 and above, brought to you by Google.

It uses power of Java 5 Annotations to replace new with @Inject.

Before delving into the new framework, lets recapture "Dependency Injection"

Before starting a surgery, the surgeon makes sure, whatever required to complete the surgery procedure are readily available.

The surgery assistant does the prep work and manages everything available before calling the surgeon to start. Imagine how horrible it would be for a surgeon to do the prep work during the surgery itself. It would leave enormous amount of risk on critical operation.

Similarly for a TransactionMananger to act on a transaction,it may depend on - Source Account, Receiver Account, Transaction modes etc.

If the transaction manager works on gathering the dependencies during the transaction, it will not only affect the transaction time , but can also impact on quality which can lead to errors.

If an assistant makes sure, TransactionManager gets everything it requires before starting the transaction, the TM can just focus and ensure smoother transaction. If at all there is any error, it will be very easy to find out as responsibilities are way clear off.

This is what called as "Dependency Injection". In other words "Dont call me. I will call you".

public class TransactionManager{

Account sourceAccount;
Account receiverAccount;
Double amount;

void transfer(){
this.sourceAccount.debit(this.amount) ;
this.receiverAccount.credit(this.amount);
}

}

public class Account{

long accountNo;
String name;

void debit(int a){
}

void credit(int a){

}

}

The dependencies of TransactionManager are sourceAccount and receiverAccount. All these dependencies are injected by an assistant - called - Inversion of Control Engine. [IoC Engine]

The IoC engine just requires following configuration to perform this.

< bean name="transactionManager" class="TransactionManager" >
< property name="sourceAccount" ref="sourceAccount"/>
< property name="receiverAccount" ref="receiverAccount"/>
< property name="amount" value="100"/>
</bean >

< bean name="sourceAccount" class="Account" >
< property name="accountNo" value="123" />
< property name="accountName" value="first last" />
</ bean >

< bean name="receiverAccount" class="Account" >
< property name="accountNo" value="89234" />
< property name="accountName" value="xyz man" />
</ bean >



Without dependency injection the transfer() would have been like this

void transfer(){
Account sourceAccount=new Account();
sourceAccount.setAccountNo(123);
sourceAccount.setName("first last");

Account receiverAccount=new Account();
receiverAccount.setAccountNo("89234");
receiverAccount.setName("xyz man");

sourceAccount.debit(100);
receiverAccount.credit(100);

}


Instead of tying the dependencies too tightly and mixing with core functionality, the assistant [IoC - Inversion of Control or Dependency Injection Engine] makes sure all the dependencies are readily available when required.

This not only makes the surgeon [TransactionManager] job easier, but also ensures testability and maintenance. If the amount or Account implementation changes in future, its very easy to update the code. Just change the configuration and you all done. The IOC will keep you updated and will deliver you all dependencies at required time


Refer for more info.
http://code.google.com/p/google-guice/

Comet - Reverse Ajax - Server Push

We see many attempts to bring Rich User experience - more of a- app like features to the modern browser users.

Numerous frameworks developed based on Java scripts handling browser DOM model to achieve Rich UI. These frameworks are currently leveraging the Asynchronous Requests to the server- AJAX. These requests are made from browser to server, however little research or development explored on the other way around - server pushing data to active browser sessions which would result in more of applet like applications on browser still proving better performance.

Comet - a new word - used to describe a web application model in which a long-held HTTP request allows a web server to push data to a browser, without the browser explicitly requesting it

There are many methods currently employed for this technique.

Example applications:

Google chat , Meboo

Javascript : Anything can convert to Boolean!

Most powerful languages are very simple to program and very complex to master. and no doubt Javascript is one among them!

As Javascript as minimal data types, and in times anything can be potentially converted to boolean value, and the reason is few values [0, false, '',undefined, null] are equate themselves to boolean FALSE.

So, here is an example to convert any data type to equate to a boolean value.

var val=5;

val=!!val;

alert('Numeric Value:'+val); //true




val=0;

val=!!val;

alert('Zero Numeric Value:'+val); //false




val = '';

val =!!val;

alert('Empty space value:'+val); //false




val = undefined;

val = !!val;

alert('undefined value:'+val); //false




val = new Array();

val=!!val;

alert('Array Object value:'+val); //true




val= {};

val=!!val;

alert('Empty Object value:'+val); //true




val=false;

val=!!val;

alert('Boolean value:'+val);  //false




val= null;

val=!!val;

alert('Null value:'+val); //false




Albeit this power can mislead to type safety, it certainly adds great value when used wisely.

Hope you do so :-)

eRights - Unified Access & Concurrency Control for IT Products

We might have used Lightweight Directory Access Protocol [LDAP] used to control user authentication and entitlements for enterprise applications. 

Albeit open source ldap can fulfill extensive access control mechanism complex entiltments for enterprises, it potentially lacks concurrency enforcement for which many of us, would have employed other custom solutions [like tracking session id/access id with respect to application usage etc]

eMeta attempts to bridge the gap between access & concurrency controls through its unified approach via its eRights suite.

The product description goes as below.....

"eRights is an enterprise-information commerce software package for the online 

information industry. It provides authentication, access control, concurrency control. 

It helps IT product enterprises to  implement sophisticated personalized licenses 

and allow organizations to extract products from large databases of information.

eRights directly addresses the problems of selling and distributing information 

online by recognizing that information products are built from elements of 

content and application services that can be packaged in different ways to 

address different markets. eRights optimizes the many paths and usage terms and 

makes user, access, and product information available to other components of 

content distribution systems, such as personalization and content management 

software, content protection technologies, and payment systems."

Lets analyze a custom implementation on eRights :-

Resource 

The bottom of hierarchy starts with resource - that can have id and name. This is atomic unit of access control that can be devised. 

Product

The set of resources are grouped together and called a product - this can be real world business entity. 

User

This represents individual user / role that can access the product. Apart from regular name, id, password,  details it can also store as much customer info as possible.

Group

The set of users - called as Group that represents a team/organiztion unit/ a department etc.

Other than individual user access - group login/password also can be configured. 

License

The users and/or groups are assigned a product or set of products with set of rules governing validity time period, trial/preferred access, concurrent usage, number of logins etc which is called Licensing.

Concurrency Maintenance:

When a user logs in, an eRights session can be tied with the user record which can keep track of concurrency. 

Programming interfaces:

eRights offers application programming interfaces for many standard programming languages [Java, .Net, Perl etc] which enables application developers seamlessly integrate eRights into their application suite.

Conclusion

Concurrency control is certainly a step ahead on product marketing and its worth to consider unified solutions like eRights.

More info: 

http://www.emeta.com

Composite Configuration

This Configuration class allows you to add multiple different types of
Configuration to this CompositeConfiguration. If you add Configuration1, and
then Configuration2, any properties shared will mean that Configuration1 will be
returned. You can add multiple different types or the same type of properties
file. If Configuration1 doesn't have the property, then Configuration2 will be
checked.




























Here, if you want to override any of the configurations mentioned by default, simply define them in APP_1

How to check what version of JavaScript supported in Browser

Run the following code in any browser thru HTML page. You will get the answer.



<script type="text/javascript">
var jsver = 1.0;
</script>
<script language="Javascript1.1">
jsver = 1.1;
</script>
<script language="Javascript1.2">
jsver = 1.2;
</script>
<script language="Javascript1.3">
jsver = 1.3;
</script>
<script language="Javascript1.4">
jsver = 1.4;
</script>
<script language="Javascript1.5">
jsver = 1.5;
</script>
<script language="Javascript1.6">
jsver = 1.6;
</script>
<script type="text/javascript">
document.write('Javascript version ' + jsver+ ' supported');
</script>


Note:

Firefox, Netscape 7/8, Mozilla, and Opera 7+ all support version 1.6
Netscape 6 supports version 1.5
Opera 6 supports version 1.4
Netscape 4.5, Opera 5, and Internet Explorer 6 support version 1.3
Netscape 4 supports version 1.2

extJS - Javascript library for RIA

Ext JS is a cross-browser JavaScript library for building rich internet applications. It includes:

High performance, customizable UI widgets

Well designed and extensible Component model

An intuitive, easy to use API

Commercial and Open Source licenses available

Scope in Javascript

Variable scope describes when a piece of information is accessible.
When a variable is created, the value it stores is only available for a certain part of the code execution.
Memory is set aside to store that piece of information and then freed when it is no longer needed.


JavaScript, a variable declared outside of a function is available inside a function:


var name = "Jonathan";
function showme()
{
alert(name); // will display "Jonathan"
}
showme();


A variable declared within a function will not be available outside of a function.


function showme()
{
var name = "Jonathan";
}
showme();
alert(name); // name will be undefined


#1 Do not use global variables from within a function
Instead, pass in any required values as parameters to the function.

Using our JavaScript example from before we can do this:

var name = "Jonathan";
function showme(myname)
{
alert(myname); // will display "Jonathan"
}
showme(name);
alert(name); // will display "Jonathan"


#2 Use object-oriented programming (OOP)
This mantra is similar to the first point, but on a larger scale. Instead of a collection of functions that perform related tasks, the functions become methods of an object. (A method is a function that belongs to an object.) Values can then be passed into the object in a variety of useful ways:

By setting the properties of an object
By passing values as parameters of a method
By passing values as parameters of the constructor (the method that gets executed when an object is first instantiated)
Here’s a quick JavaScript OOP example:

function Person(myname)
{
this.name = myname;
}
var me = new Person("Jonathan");
alert(me.name);



Scope in Javascript

this keyword refers to current object

Dojo - Javascript Framework

Overview

- Dojo is a HTML and Javascript Framework for Rich interactive Applications
- Dojo offers many widgets, utilities and ajax libraries to develop your application.
- Open source under BSD license
- Robus Ajax framework
- Programmer can use just API to build powerful functions
-

Basic components

Tree,Button,Calendar control,Grid,List box

Pros

Associative arrays
Loosely typed variables
Regular expressions
Objects and classes
Highly evolved date, math, and string libraries
W3C DOM support in the Dojo

Challenges:

- Browser dependent; applicable for any client framework
- No way to hide dojo code in view source

What is === operator in Javascript?

=== is strict equality operator ,it returns true only when the two operands are having the same value without any type conversion.

Example

alert(1=="1"); returns true
alert(1==="1"); returns false



Javascript Cookies

Cookies

Cookies were originally invented by Netscape to give 'memory' to web servers and browsers. The HTTP protocol, which arranges for the transfer of web pages to your browser and browser requests for pages to servers, is state-less, which means that once the server has sent a page to a browser requesting it, it doesn't remember a thing about it. So if you come to the same web page a second, third, hundredth or millionth time, the server once again considers it the very first time you ever came there.

This can be annoying in a number of ways. The server cannot remember if you identified yourself when you want to access protected pages, it cannot remember your user preferences, it cannot remember anything. As soon as personalization was invented, this became a major problem.

Cookies were invented to solve this problem. There are other ways to solve it, but cookies are easy to maintain and very versatile.

How cookies work
A cookie is nothing but a small text file that's stored in your browser. It contains some data:

A name-value pair containing the actual data
An expiry date after which it is no longer valid
The domain and path of the server it should be sent to

As soon as you request a page from a server to which a cookie should be sent, the cookie is added to the HTTP header. Server side programs can then read out the information and decide that you have the right to view the page you requested or that you want your links to be yellow on a green background.

So every time you visit the site the cookie comes from, information about you is available. This is very nice sometimes, at other times it may somewhat endanger your privacy. Fortunately more and more browsers give you the opportunity to manage your cookies (deleting the one from the big ad site, for example).

Cookies can be read by JavaScript too. They're mostly used for storing user preferences.

name-value

Each cookie has a name-value pair that contains the actual information. The name of the cookie is for your benefit, you will search for this name when reading out the cookie information.
If you want to read out the cookie you search for the name and see what value is attached to it. Read out this value. Of course you yourself have to decide which value(s) the cookie can have and to write the scripts to deal with these value(s).

Expiry date

Each cookie has an expiry date after which it is trashed. If you don't specify the expiry date the cookie is trashed when you close the browser. This expiry date should be in UTC (Greenwich) time in the format created by the Date.toGMTString() method

Domain and path

Each cookie also has a domain and a path. The domain tells the browser to which domain the cookie should be sent. If you don't specify it, it becomes the domain of the page that sets the cookie, in the case of this page www.quirksmode.org.Please note that the purpose of the domain is to allow cookies to cross sub-domains. My cookie will not be read by search.quirksmode.org because its domain is www.quirksmode.org . When I set the domain to quirksmode.org, the search sub-domain may also read the cookie.I cannot set the cookie domain to a domain I'm not in, I cannot make the domain www.microsoft.com . Only quirksmode.org is allowed, in this case.
The path gives you the chance to specify a directory where the cookie is active. So if you want the cookie to be only sent to pages in the directory cgi-bin, set the path to /cgi-bin. Usually the path is set to /, which means the cookie is valid throughout the entire domain.This script does so, so the cookies you can set on this page will be sent to any page in the www.quirksmode.org domain (though only this page has a script that searches for the cookies and does something with them).

document.cookie

Cookies can be created, read and erased by JavaScript. They are accessible through the property document.cookie. Though you can treat document.cookie as if it's a string, it isn't really, and you have only access to the name-value pairs.

If I want to set a cookie for this domain with a name-value pair 'ppkcookie1=testcookie' that expires in seven days from the moment I write this sentence, I do

document.cookie =
'ppkcookie1=testcookie; expires=Thu, 2 Aug 2001 20:47:11 UTC; path=/'
First the name-value pair ('ppkcookie1=testcookie')
then a semicolon and a space
then the expiry date in the correct format ('expires=Thu, 2 Aug 2001 20:47:11 UTC')
again a semicolon and a space
then the path (path=/)

This is a very strict syntax, don't change it! (Of course the script manages these dirty bits for you)

Also, even though it looks like I'm writing this whole string to the string document.cookie, as soon as I read it out again I only see the name-value pair:ppkcookie1=testcookie
If I want to set another cookie, I again do

document.cookie ='ppkcookie2=another test; expires=Fri, 3 Aug 2001 20:47:11 UTC; path=/'

The first cookie is not overwritten, as it would when document.cookie would be a real string. Instead the second one is added to document.cookie, so if we read it out we get

ppkcookie1=testcookie; ppkcookie2=another test
If I reset a cookie

document.cookie ='ppkcookie2=yet another test; expires=Fri, 3 Aug 2001 20:47:11 UTC; path=/'

the old cookie is overwritten and document.cookie readsppkcookie1=testcookie; ppkcookie2=yet another test

To read out a cookie you have to treat document.cookie as a string and search for certain characters (semicolons, for instance) and for the cookie name. I'll explain how to do it below.
Finally, to remove a cookie, set it with an expiry date before today. The browser sees that the cookie has expired and removes it.

document.cookie ='ppkcookie2=yet another test; expires=Fri, 27 Jul 2001 02:47:11 UTC; path=/'

Example
If you're thoroughly confused by all this strange syntax, try the example below. You can set two cookies, ppkcookie1 and ppkcookie2. Fill in the desired value in the text box.
The value of the cookie should be

I set the cookies to remain active for seven days. If you return to this page within that time, you'll get an alert that the cookie(s) is/are still active. Try it by setting a cookie, then reloading this page.

These are the three scripts you need.

function createCookie(name,value,days) {
if (days) {
var date = new Date();
date.setTime(date.getTime()+(days*24*60*60*1000));
var expires = "; expires="+date.toGMTString();
}
else var expires = "";
document.cookie = name+"="+value+expires+"; path=/";
}
function readCookie(name) {
var nameEQ = name + "=";
var ca = document.cookie.split(';');
for(var i=0;i < ca.length;i++) {
var c = ca[i];
while (c.charAt(0)==' ') c = c.substring(1,c.length);
if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
}
return null;
}
function eraseCookie(name) {
createCookie(name,"",-1);
}

Explanation

functions are not very difficult, the hardest part is creating the correct syntax for setting a cookie.
createCookie

When calling createCookie() you have to give it three bits of information: the name and value of the cookie and the number of days it is to remain active. In this case the name-value pair should become ppkcookie=testcookie and it should be active for 7 days.createCookie('ppkcookie','testcookie',7)

If you set the number of days to 0 the cookie is trashed when the user closes the browser. If you set the days to a negative number the cookie is trashed immediately.
The function receives the arguments and starts doing its job.function createCookie(name,value,days) {
First of all see if there is a days value. If there isn't we don't need to do the time calculation. if (days) {
If there is, create a new Date object containing the current date. var date = new Date();
Now get the current Time (in milliseconds) and add the required number of days (in milliseconds). Set the Time of the date to this new value, so that it now contains the date in milliseconds that the cookie should expire. date.setTime(date.getTime()+(days*24*60*60*1000));
Set the variable expires to this date in the UTC/GMT format required by cookies. var expires = "; expires="+date.toGMTString();
}
If 0 is passed to the function, expires is not set and the cookie expires when the user closes his browser.. else var expires = "";
Finally write the new cookie into document.cookie in the correct syntax. document.cookie = name+"="+value+expires+"; path=/";
}
Cookie created.
readCookie
To read out a cookie, call this function and pass the name of the cookie. Put the name in a variable. First check if this variable has a value (if the cookie does not exist the variable becomes null, which might upset the rest of your function), then do whatever is necessary.var x = readCookie('ppkcookie1')
if (x) {
[do something with x]
}
The function receives the argument and starts.function readCookie(name) {
We're going to search for the name of the cookie, followed by an =. So create this new string and put it in nameEQ: var nameEQ = name + "=";
Then split document.cookie on semicolons. ca becomes an array containing all cookies that are set for this domain and path. var ca = document.cookie.split(';');
Then we go through the array (so through all cookies): for(var i=0;i < ca.length;i++) {
Set c to the cookie to be checked. var c = ca[i];
If the first character is a space, remove it by using the substring() method. Continue doing this until the first character is not a space. while (c.charAt(0)==' ') c = c.substring(1,c.length);
Now string c begins with the name of the current cookie. If this is the name of the desired cookie if (c.indexOf(nameEQ) == 0)
we've found what we were looking for. We now only need to return the value of the cookie, which is the part of c that comes after nameEQ. By returning this value we also end the function: mission accomplished. if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
}
If, after having gone through all cookies, we haven't found the name we're looking for, the cookie is not present. We return null. return null;
}
Cookie read.
eraseCookie

Erasing is extremely simple.

eraseCookie('ppkcookie')

Pass the name of the cookie to be erased and call createCookie() to set the cookie with an expiry date of one day ago.

function eraseCookie(name) {
createCookie(name,"",-1);
}

The browser, seeing that the expiry date has passed, immediately removes the cookie.

ICU DateFormat - Year Representation

The format character 'Y' (upper case) is intended to be used in conjunction with ISO 8601 "week of year" notation whereas the format character 'y' (lower case) represents the actual year.

Example:
December 31, 2008 formatted with YYYY/MM/dd yields 2009/12/31
December 31, 2008 formatted with yyyy/MM/dd yields 2008/12/31

ICU - International Components for Unicode

What is ICU?

ICU stands for International Components for Unicode.

ICU is a cross-platform Unicode based globalization library. It includes support for locale-sensitive string comparison, date/time/number/currency/message formatting, text boundary detection, character set conversion and so on.

History

ICU was originally developed by the Taligent company. The Taligent team later became the Unicode group at the IBM® Globalization Center of Competency in Cupertino.

Developing globalized software is a continuous balancing act as software developers and project managers inadvertently underestimate the level of effort and detail required to create foreign-language software releases.In general, the standard process for creating globalized software includes "internationalization," which covers generic coding and design issues, and "localization," which involves translating and customizing a product for a specific market.

ICU Services provides standard platform-independent libraries to resolve this issue.

The ICU services support all major locales with language and sub-language pairs.

Services of ICU

ICU enables you to write language-independent C and C++ code that is used on separate, localized resources to get language-specific results. ICU supports many features, including language-sensitive text, dates, time, numbers, currency, message sorting, and searching. ICU provides language-specific results for a broad range of languages.

The set of services provided by ICU includes:

Strings, Properties and CharacterIterator
Conversion Basics
Locale and Resource Management Support
Date and Time Support
Format and Parse
Formatting Numbers
Transformations
Searching and Sorting
Text Analysis
Text Layout
Search String


ICU and Java

Java™ classes developed at Taligent were incorporated into the Java Development Kit (JDK) 1.1 developed by Sun® Microsystems. The classes were then ported to C++ and later some classes were also ported to C. The classes provide internationalization utilities for writing global applications in C, C++, or Java programming languages.

ICU for Java (ICU4J) includes enhanced versions of some of these classes, plus additional classes that complement the classes in the JDK. C and C++ versions of the same international functionality are available in ICU for C (ICU4C). The APIs differ slightly due to language differences and new functionality.

For example, ICU4C includes a character converter API.ICU4J and ICU4C keep the same development goals. They both track additions to the Java internationalization APIs and implement the latest released Unicode standard. They also maintain a single, portable source code base.

Reference

http://icu-project.org/