How To - Java

last update 12^th November 2004
The latest Version can be found at http://home.vr-web.de/jSwi/SoftDesk/HowToJava.html

Why Java

Java is a Programming language which can be used on many Platforms like Windows™, MAC OS™, Linux, Unix, OS/390™, AS400™ and some more. For each plattform is Java Runtime Environment (JRE) available. On the one hand you need a compiler (JAVAC) to generate Class files (*.class) from source Files (*.java), on the other hand you need a Java Runtime Environment (JRE) to execute the class files. The class files do not need to be compiled on each platform. Once compiled they will run on nearly every JRE.

Where to get a JRE (Java Runtime Environment)

Look at Sun ,IBM or Apple to get the JRE.

What is a JDK (Java Development Environment)

The JDK contains all the neccesary files to create you own Java Applications;including a Compiler, a JRE, a debugger and other Tools for development and deployment.

What is a JAR file (Java Archive)

A JAR File is a file containis the neccesary class files to run a Java Application. The class files can decompressed with WinZip™ or Stuffit™ but there is no need to do so, because the JRE can handle such JAR files.

How to get it working

Mac OS X

Before starting copy the appripiate pdb file and the jar file into the same folder. On MAC OS X you fill find in the Application Folder, a Application called Terminal. After starting that application you will get a window where you can type the command listed in the documentation of the Java Software.

To check if Java is available simple type java and press the enter key. Naviage to the Folder where the jar fand the pdb file is located with the cd (change directory) command. If you start the terminal Application you are in the user folder. With cd .. (don not forget the blank between cd and the two dots).

With cd / you navigate to the computers root. In the Folder Drives you find a list of all available drives. You can check this with the ls (list) command.