The Diffrence between AWT and Swing......

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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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