In order to compile and run Java programs on a computer, the computer 
needs to be able to find the java programs you will use - javac.exe for 
compiling source, and java.exe for running Java programs.  In order for 
this to work, your PATH environment variable must be set properly.

The Java programs, in turn, will need to know where to look on your 
computer to find .class files needed to resolve references.   These 
references include custom classes that you write as well as classes written 
by developers at Sun (for example:  java.util.HashMap or 
java.lang.String).  In order for this to work, your CLASSPATH environment 
variable must be set properly.

These instructions refer to something called the <JAVA_INSTALL_DIR> - 
this is the directory that you installed the Java SDK into.  For most of 
you, that will typically be c:\jdk1.3.1 or c:\program files\jdk1.3.1  
Replace <JAVA_INSTALL_DIR> with the actual directory you installed into.  
YOU MUST INSTALL THE JDK TO COMPILE JAVA SOURCE FILES ON YOUR COMPUTER.

To install the JDK:  
Insert the CD that came with the book into your CD drive.  Go to ...
<CD-DRIVE>\software-win\sj-sdk\j2sdk-1_3_1-win.exe.


To set your path variable:
--------------------------
There are various places you can "permanently" set environment 
variables[1] on the different versions of Windows, but the following steps, 
when carried out at a command prompt will always work *for the duration of 
that command prompt*:

set PATH=%PATH%;<JAVA_INSTALL_DIR>\bin;

example:
set PATH=%PATH%;c:\jdk1.3\bin;


To set your classpath variable:
------------------------------
Again, you may eventually figure out how to permanently set this 
variable, but it will always work that if you type the following commands 
into a command prompt, the classpath variable will be set correctly for 
the duration of that command prompt:

This line makes sure all the standard Java classes are available to you 
- it is not technically required unless you are using a program like Jikes.exe 
to compile.

set CLASSPATH=<JAVA_INSTALL_DIR>\jre\lib\rt.jar

This next line adds the CURRENT DIRECTORY (this changes as you change 
directories) to the classpath as well.  Dot represents the current 
directory.
set CLASSPATH=%CLASSPATH%;.

If you do not wish to (or cannot for some reason) set the classpath at the 
command prompt, you can always specify it each time you invoke java.exe or 
javac.exe by adding the -classpath switch to the javac.exe program, or the 
-cp switch to the java.exe program.

For EXAMPLE:

javac -classpath c:\jdk1.3.1\jre\lib\rt.jar;.; -d . *.java

Remember, this is an example only, you may have installed the JDK into a 
different directory (see JAVA_INSTALL_DIR discussion above).

As your work on the class project progresses, you will need to use classes 
and interfaces that I have written for you.  They are available for download
from the website in a jar file named partone.jar.

The preferred way of using classes packaged in a jar file is to simply add
the jar file to your classpath.  Note that I have adapted the previous command
to now use the partone.jar file as part of the classpath:

javac -classpath c:\jdk1.3.1\jre\lib\rt.jar;.;partone.jar  -d . *.java

The command above assumes that you have saved the partone.jar file in the same
directory as your source code.   You could have saved it to another directory
though:

javac -classpath c:\jdk1.3.1\jre\lib\rt.jar;.;c:\downloads\partone.jar  -d . *.java

In this last case, the partone.jar file was saved to the c:\downloads directory.

To compile:
----------
Remember that we always place our source/classes in packages, so you 
will need to rememeber to compile with the -d flag telling javac where to 
start creating the directory tree that mimics the package structure.  
Since the current directory is in the classpath (from step #2 of 
classpath instructions), the following is a suitable command:

javac -d . <MY_SOURCE_FILE_NAME>

Remember to add the .java extension - this is the FILENAME of the 
source you want to compile, not the name of the class.

To run:
------
Make sure you are running your program from the same directory that you 
compiled it from.

java <MY_CLASS_NAME>

Remembed to OMIT the .class extension.  This is the CLASSNAME not the 
FILENAME of the class.


If you understand how classpaths work, you should understand how to 
adapt these instructions to always compile your source files to a common 
base directory.  Basically, as long as the directory that you pass to the -d . 
switch when you compile is also listed in your classpath, you will be OK.

For example:

C:\
  |
  +--- cis218
  		|
  		+ classes
  		|	|
  		|	+ edu
  		|		|
  		|		+ cod
  		|			|
  		|			+ cis218
  		|				|
  		|				+ Source1.class
  		|				+ Source2.class
  		|				+ Source3.class
  		+ source
  			|
  			+ Source1.java
  			+ Source2.java
  			+ Source3.java
  			
In this example, the compilation command would be as follows
(from the c:\cis218\source directory):

javac -d c:\cis218\classes *.java

Then to run one of the classes (let's say that Source1.java includes
a public static void main(String[] args) method):

java -cp c:\cis218\classes edu.cd.cis218.Source1

You may also elect to keep your source files in directories that mirror 
their package structure as well (this is a common and well-accepted 
practice in real life).


[1]
Windows 98:   	Start | Run | msconfig 
			  	Set the variables as above under the AUTOEXEC.BAT tab
Windows NT:	  	Start | Settings | Control Panel | System
				Set the variables as above under the ENVIRONMENT tab
Windows 2000:	Similar to NT, I think, but may be the ADVANCED tab
Windows XP:		Don't know off the top of my hea