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Java Applications and Components

Java Applets and Components

Java Frequently Asked Questions:
    1. What is Inheritance?
    2. What is Polymorphism?
    3. What is Encapsulation?
    4. Avoiding the Divide by Zero Error
    5. Public Classes in Java Source Files
    6. The Import Statement in Java
    7. Classes with Default Access
    8. What are Local Variables?
    9. What is an Abstract Method?
    10. Data Structures
    11. What is Autoboxing and Auto-Unboxing?
    12. What is multithreading?
    13. What are Threads?
    14. Thread States
    15. What is the Purpose of Synchronization?
    16. Thread Interaction
    17. Can You Start a Thread Twice?

Features of Java

The Java programming language is a very powerful and extensive programming language designed to be used on any computer system, ranging from cell phones and PDAs to mainframes, with the Java Runtime Environment installed on it. A Java program written and compiled on one computer system should be able to run on any other computer system so long as that computer has the Java Runtime Environment installed. This platform independence allows Java developers to only have to write one copy of their program, which can then be run on any computer. This ability is often achieved by compiling to Java Byte Code rather than directly to machine code. At run time the Java Runtime Environment then converts the Java Byte Code to machine code and is run through the Computer Processor. The Java Programming Language is also an object-oriented programming language, making far easy to create and maintain programs both large and small. The object-oriented nature of the Java Programming language also allows the programmer to reuse large amounts of code that has already been written. One feature of the Java Programming language which is very useful is the ease of web program creation. With only minor changes to his or her program, a Java programmer can quickly convert a standalone executable program to a Java Applet able to be implanted into a website and able to run on any computer system with access to that webpage and the Java Runtime Environment installed. Java also helps to protect inexperienced Java programmers from themselves by not allowing the use of pointer variables and similar things often found in other programming languages. While some Java programmers view this to be a good thing, there are those who feel that this is making the language less robust then other languages which have these abilities, The C++ Programming Language for example.

Use of Java in the IT Industry

In the years since the Java Programming Language was first released it has come to be one of the most widely used Computer Programming Languages. In fact, “at the May 2006 JavaOne conference, Sun announced that there were one billion java enabled mobile phones and handheld devices” (Java How to Program Page 3). This figure does not even consider the number of other computer devices that can use Java based programs. However, an updated version of this information about the widespread use of the Java Programming Language, shows that there are over 800 million PCs, over 1.5 billion mobile phones and other handheld devices, 2.2 billion smart cards plus set-top boxes, printers, web cams, games, car navigation systems, lottery terminals, medical devices, parking payment stations, etc (www.java.com/en/about ). As the World Wide Web was beginning to grow rapidly in the early 1990’s Sun Micro Systems understood what a programming language which would allow programmers the ability to create dynamic content on web pages could mean; The Java Programming Language was their answer to this. When the Java Programming Language was first announced to the business world in May of 1995 at an industry conference it was quickly seen that the Java Programming Language could provide a way to create large enterprise applications and improve web server’s functions (Java How to Program Page 9). The Java Programming Language was also been used to create fairly successful computer games, such as Runescape, an MMORPG, which on a good night could have as many as nearly 200,000 people playing it at any given time (www.runescape.com). In March of 2007, BBC News ran an article about MMOPRG games, and ranked Runescape as the 4th largest with nearly one million subscribers (BBC News Article). The Java Programming Language is also used for mobile phone applications, remote processors, and low-cost consumer products. The Java Programming Language has grown to have been used in nearly every area of computer technology.