how to create executable jar file of java...

Step 1: Locate the Jar utility in the JDK folder

• Before you do anything else, make sure that you have jdk installed on your computer. You also will need to know the directory to the jdk. Specifically, you will need the path to the Jar utility that is inside your jdk folder. My path to jar is:

·          C:\"Program Files"\Java\jdk1.6.0_02\bin\jar

• As you can probably tell, I'm using Java 1.6 and within the 'bin' folder is jar which is the program that you will use to make jar files. Basically typing that line up above tells the command prompt that we're going to run the jar utility which is located in the folder C:\"Program Files"\Java\jdk1.6.0_02\bin
• On your own computer, the path to the jar utility will probably look similar, it depends on where you installed the jdk to.

Step 2: Create themanifest file

Since you could potentially be compiling many files into one jar file, Java needs to know which one will have the main method. Our example is a bit more trivial since we're just compiling one class into a Jar. Nonetheless, the way that Java knows which of classes has the main method is from a single line in what's known as a manifest file. A manifest file can be a text file made with notepad. I called my manifest file manifest.txt, my manifest file says:

Main-Class: JarDemo

Use the command prompt to navigate to where the JarDemo.class and manifest.txt file are saved and type :

C:\>  C:\Path\to\jdk\bin\jar cvfm jarDemoCompiled.jar manifest.txt JarDemo.class
If you don't like always typing out the generally long path to the jdk. You can set the path as follows

    c:> path c:\path\to\jdk\bin;%path%

Doing so would allow you to type

C:\>  jar cvfm jarDemoCompiled.jar manifest.txt JarDemo.class

When I don't usde the shortcut on my computer, I must type:

C:\>  C:\"Program Files"\Java\jdk1.6.0_02\bin\jar cvfm jarDemoCompiled.jar manifest.txt JarDemo.class

cvfm means "create a jar; show verbose output; specify the output jar file name (jarDemoCompiled.jar); specify the manifest file name(manifest.txt) and use the file JarDemo.class to create the jar
  

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A Look Over Keyboard History and Generation.

           Input devices are hardware components that enable users to interact with a computer. Without input devices, we cant feed instructions to a computer. There are lots of possible input devices, but the two most common are a Keyboard and Mouse.

INVENTION OF KEYBOARD 

           The invention of the modern computer keyboard began with the invention of the Typewriter. Christopher Latham Sholes patente the typewriter that we commonly use today in 1868. The Remington Company mass marketed the first typewriters starting in 1877.

KEYBOARD LAYOUT  

              The keyboard is one of the most popular ways of inputting information into a computer. It is fast and accurate device.  A keyboard layout is the arrangement of the array of key across the keyboard. There are so many different types of keyboard but one keyboard layout is very familiar that layout  is “QWERTY”.

QWERTY Keyboard :

                Q,W,E,R,T,Y  is the first six latters of the top row of the alphabets of the QWERTY layout. The arrangement of QWERTYLayout was given by Sholes, the inventor of the typewriter. Besides the standard alphabet keys having the QWERTY arrangement, computer keyboards also consist of the control keys, the function keys, the numerical keys etc.

PC83-key keyboards:

            The PC 83-key was the earliest keyboard offered by IBM with its first Personal Computer.This had 83 keys. The PC/XT keyboard had many of the same features as a standard typewriter at the time, with various changes such as including the 10 function key.

84-key keyboards:

                         Later IBM added one more key with its PC AT computer keyboard to make it 84-key keyboard in the 1980s. It had 84 keys arranged in three distinct groups, with letters and commonly used keys like the Space bar occupying the center, a set of function keys to the left, and a number pad on the right. The AT keyboard used a round 5-pin connector and an electrical signaling scheme that outlived the keyboards themselves. Today, these types of keyboards are generally only used in aging legacy hardware setups and historical displays.

101-key Keyboard:

                           In 1986, IBM introduced the IBM PC/AT Model 339. Included in this last AT-family system was the new Enhanced 101-key keyboard. Little did IBM realize at the time, perhaps, but this 101-key keyboard would become the de-facto standard for keyboards for the next decade and beyond. Even today's Windows keyboards and fancy variants with extra buttons and keys are based on this layout.

108-key Keyboard:

                     A 108-key keyboard that can be connected to any computer with a PS/2 or AT keyboard connector. This is advanced model of the keyboard. This keyboard have more functionality of multimedia key which is designed at the top of keyboard.

The Dvorak Simplified Keyboard:

                  There are a number of different arrangements of alphabetic, numeric, and punctuation symbols on keys. These different Keyboard Layout arise mainly because different people need easy access to different symbols, either because they are inputting text in different languages, or because they need a specialized layout for mathematics, accounting, Computer Programming or other purpose.

NEW GENERATION KEYBOARD

Foldable Keyboard -

                           Fold able (also called flexible) keyboards are made of soft plastic or Silicon which can be rolled or folded on itself for travel. When in use, these keyboards can conform to uneven surfaces, and are more resistant to liquids than standard keyboards. These can also be connected to portable devices and smartphones. Some models can be fully immersed in water, making them popular in hospitals and laboratories, as they can be disinfected. 

Projection Keyboard -

                          Projection Keyboards project an image of keys, usually with a laser, onto a flat surface. The device then uses a camera or infrared sensor to "watch" where the user's fingers move, and will count a key as being pressed when it "sees" the user's finger touch the projected image. Projection keyboards can simulate a full size keyboard from a very small projector. Because the "keys" are simply projected images, they cannot be felt when pressed. Users of projected keyboards often experience increased discomfort in their fingertips because of the lack of "give" when typing. A flat, non-reflective surface is also required for the keys to be projected. Most projection keyboards are made for use with PDA and smartphones due to their small form factor.

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Various Mobile Operating Systems....

Various Mobile Operating Systems:-

                                          There are So many types of Operating Systems available in Mobile Markets. Some are Expensive, Some are Free, Some are Chargeable, and some are Costly. In This Post we take a look and get knowledge of these operating Systems.

1. Android:-

Android (AN-droyd) is a Linux-based operating system designed primarily for touchscreen mobile devices such as smartphones and tablet computers. Initially developed by Android, Inc., which Google backed financially and later bought in 2005, Android was unveiled in 2007 along with the founding of the Open Handset Alliance: a consortium of hardware, software, and telecommunication companies devoted to advancing open standards for mobile devices. The first Android-powered phone was sold in October 2008.

Android is open source and Google releases the code under the Apache License. This open-source code and permissive licensing allows the software to be freely modified and distributed by device manufacturers, wireless carriers and enthusiast developers. Additionally, Android has a large community of developers writing applications ("apps") that extend the functionality of devices, written primarily in a customized version of the Java programming language. In October 2012, there were approximately 1,000,000 apps available for Android, and the estimated number of applications downloaded from Google Play, Android's primary app store, was 50 billion as of Sep 2013. A developer survey conducted in April–May 2013 found that Android is the most popular platform for developers, used by 71% of the mobile developer population.

Symbian

Symbian was a mobile operating system (OS) and computing platform designed for smartphones and currently maintained by Accenture. Symbian was originally developed by Symbian Ltd. as a descendant of Psion's EPOC and runs exclusively on ARM processors, although an unreleased x86 port existed. The current form of Symbian is an open-source platform developed by Symbian Foundation in 2009, as the successor of the original Symbian OS. Symbian was used by many major mobile phone brands, like Samsung, Motorola, Sony Ericsson, and above all by Nokia. It was the most popular smartphone OS on a worldwide average until the end of 2010, when it was overtaken by Android. Symbian rose to fame from its use with the S60 platform built by Nokia, first released in 2002 and powering most Nokia smartphones. UIQ, another Symbian platform, ran in parallel, but these two platforms were not compatible with each other. Symbian was officially released in 4 2010 as the successor of S60 and UIQ, first used in the Nokia N8, to use a single platform for the OS. In May 2011 an update, Symbian Anna, was officially announced, followed by Nokia Belle (previously Symbian Belle) in August 2011.

Windows OS

Windows Mobile is a family of mobile operating systems developed by Microsoft for smartphones and Pocket PCs. Windows Mobile is the predecessor of Windows Phone. In February 2010, Microsoft announced Windows Phone to supersede Windows Mobile. As a result, Windows Mobile has been deprecated. Windows Phone is incompatible with Windows Mobile devices and software. The last version of Windows Mobile, released after the announcement of Windows Phone, was 6.5.5. Most versions of Windows Mobile have a set of standard features, such as multitasking and the ability to navigate a file system similar to that of Windows 9x and Windows NT, with support for many of the same file types. Much like its desktop counterpart, it comes bundled with a set of applications to perform basic tasks. Internet Explorer Mobile is the default web browser and Windows Media Player is the default media player used for playing digital media. Microsoft Office Mobile, the mobile versions of Microsoft Office, is the default office suite.

BlackBerry

BlackBerry OS is a proprietary mobile operating system developed by BlackBerry Ltd for its BlackBerry line of smartphone handheld devices. The operating system provides multitasking and supports specialized input devices that have been adopted by BlackBerry Ltd. for use in its handhelds, particularly the trackwheel, trackball, and most recently, the trackpad and touchscreen. The BlackBerry platform is perhaps best known for its native support for corporate email, through MIDP 1.0 and, more recently, a subset of MIDP 2.0, which allows complete wireless activation and synchronization with Microsoft Exchange, Lotus Domino, or Novell GroupWise email, calendar, tasks, notes, and contacts, when used with BlackBerry Enterprise Server. The operating system also supports WAP 1.2. Updates to the operating system may be automatically available from wireless carriers that support the BlackBerry over the air software loading (OTASL) service. Third-party developers can write software using the available BlackBerry API classes, although applications that make use of certain functionality must be digitally signed. 

iOS

iOS (previously iPhone OS) is a mobile operating system developed and distributed by Apple Inc. Originally unveiled in 2007 for the iPhone, it has been extended to support other Apple devices such as the iPod Touch (September 2007), iPad (January 2010), iPad Mini (November 2012) and second-generation Apple TV (September 2010). Unlike Microsoft's Windows Phone and Google's Android, Apple does not license iOS for installation on non-Apple hardware. As of August 2013, Apple's App Store contained more than 900,000 iOS applications, 375,000 of which were optimised for iPad. These apps have collectively been downloaded more than 50 billion times. It had a 21% share of the smartphone mobile operating system units shipped in the fourth quarter of 2012, behind only Google's Android. In June 2012, it accounted for 65% of mobile web data consumption (including use on both the iPod Touch and the iPad). At the half of 2012, there were 410 million devices activated.[10] According to the special media event held by Apple on September 12, 2012, 400 million devices had been sold by June 2012. The user interface of iOS is based on the concept of direct manipulation, using multi-touch gestures. Interface control elements consist of sliders, switches, and buttons. Interaction with the OS includes gestures such as swipe, tap, pinch, and reverse pinch, all of which have specific definitions within the context of the iOS operating system and its multi-touch interface. Internal accelerometers are used by some applications to respond to shaking the device (one common result is the undo command) or rotating it in three dimensions (one common result is switching from portrait to landscape mode.

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