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					               Java
How to find, install and begin
to use the Java programming
          language.
  What we‟re going to cover
A word or two on the history of some old fashion
            programming languages

           A small history of Java…

      How do I install it on my computer?

       How do I use what I just installed?
A short look at some old school
 languages, BASIC, C and C++

  It all begins in the sixties…
                      BASIC

 BASIC stands for Beginner‟s All-purpose Symbolic
                Instruction Code.


It was designed in 1963 at Dartmouth college. It was
 designed to make it easy for non-technical people to
             write computer programs.



BASIC programs were like grocery lists. You told the
program what you wanted to do and it did it in order.


               BASIC was Interpreted.
                  C and C++

Developed in the early seventies, “C” became the
     de-facto language for microcomputer
  programming in the seventies and eighties.

   “C” was not interpreted, it was compiled.

                    __________

Later, in the early eighties, C++ introduced object
orientation to the C world. Originally called “C
 with Classes”, Bjarne Stroustrup developed the
    additions to C that, in 1985, became C++.

OO is when programmers try to mimic the real
world more closely and make programs act like
    “objects” and not just be grocery lists.
     So, what have we learned?
1. BASIC was an interpreted programming language

   2. “C” was a compiled programming language

    3. “C++” brought object orientation to “C”
                      Say goodbye to the
                         seventies and
                         welcome to a
                      short (but hopefully informative)
                      history of the Java
                        programming
                           language
Authentic Seventies
      Nerds
                           James Gosling began developing Java beginning
                                              in 1991

                            It was first called “Project Green” and „Oak”

                             First developed for remote cable TV boxes
James Gosling Circa 1971
                           James Naughton creates “HotJava” in 1995. it‟s
                           a web browser that lets you run “Applets”. The
                                  entire browser is written in Java.

                                     In 1998 Java 1.2 is released

                              Java just released version 1.6 or J2SE 6…



 James Gosling Today
Java Buzzwords

                  Simple

           Object Oriented

      Architecture Neutral

                  Portable

            Multithreaded

    High Performance – JIT


Buzzwords glommed from the Core Java 2 book verbatim
FREE
Is Java Interpreted or Compiled?
           Is Java Interpreted or Compiled?

                            BOTH!!
               Java programs are compiled to Bytecode


        Bytecode is then interpreted by a JVM, or Java Virtual
       machine. The virtual machine is what runs your program


It‟s the JVM that cares about your Operating system, NOT THE PROGRAM!


                 WORA - Write Once, Run Anywhere!
Is Java Object Oriented?
         Is Java Object Oriented?

                     YES!

Every bit of code in a Java program is in a “Class”


Code Reuse, Encapsulation, Polymorphism, Inheritance
DUKE!
 Why? Who knows…
           Downloading a Java JDK

               You want a JDK, not just a JRE

       Create a “Temp” directory on your PC or laptop

                  Go to http://java.sun.com

 Go to the “Popular Downloads” section and select “Java SE”

  Select a JDK without Netbeans (We‟ll talk about this later)

              Agree to the accept the use policy

Right Click and Save the Offline Windows JDK to your temp dir
                  Installing a Java JDK
            Go to your “Temp” dir using Windows Explorer

Make sure no other apps are running and double click the install program
                you just downloaded. Follow the steps.

                           I install in C:\Java

 Watch fom multiple JREs and JDKs! In Windows the Registry runs the
            show now, not the JAVA_HOME env variable

       Test with a Command Prompt Window and “java –version”

             Add C:\Java\”Java ver”\bin to your PATH var

 Be sure to add “current directory” to the CLASSPATH (if you had one)
           Now, Lets test it

           DOS - Command Prompt

          Make a directory structure

            Type “Edit” and Voila

                    PSVM

            Test JAVAC and JAVA

Create Bytecode ( the *.class file) with “Javac”

          Run Program with “Java”
If we were
 lucky we
    got
something
that looks
like this…
                 Help on the Web
           http://java.sun.com/javase/6/docs/api/

                 http://www.javaranch.com

         http://java.sun.com/docs/books/tutorial/

               http://www.sorcon.com/java2/

             http://remus.rutgers.edu/freestuff

                    Got an Error?
Just type it verbatim into Google and you usually can find the
       answer to your question or solve your problem.

  Wikipedia is a good place to get background and history
          On anything, and Java is no exception
Remember….
                                Java is both compiled and
                                        interpreted

                                 Java is Object Oriented

                           http://java.sun.com is Java‟s home

 You want the Java Development Kit (JDK) , not a JRE or J2EE

      Take your time, use temp directories for setup files

       Test with a simple “Hello World” after you install

     Use the Web for help (Google errors, javaranch, etc.)
THANK YOU
 http:\\remus.rutgers.edu\java\workshops\

 Any questions or comments can be sent to me
          At biglars@cs.rutgers.edu


                 Be Good Now…




            ©2007 Rutgers University & Lars Sorensen

				
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