Running Java as a Command Line Application
(Windows)
- Install
the Java SDK as described in other instructions.
- To
develop a program in Java, you will typically write several files, one for
each class. Set up a directory
and store all your Java files for one program in this directory.
- Write
each class and store it in a file with the same name as the class, including
case, with a .java
extension. For example, the
class defined by
public
class ThisClass
{
...
would be stored in the file ThisClass.java.
These program files can be written
in any editor and should be stored as text with the .java extension.
- To
compile and run, open a command prompt window or DOS window.
There is usually an icon for this on the Start menu, either
on the main menu or under accessories.
It is called DOS on Win95 and Win98 and it is called Command
Prompt on Win2000 and WinXP. Under unix or linux systems you simply use
the command interface.
- In
your command line window, change directory to the directory where your
programs are located to do your work.
- To
compile the code in a file like the example above.
javac
ThisClass.java
- You
can only run a file as an application that contains the method static
void main. To run the
main method from such a class, type.
java
ThisClass
You can do much of your Java programming in this way. There
is one additional setup process if you want to use libraries that are stored
in a different directory from the one where you do your work.
These libraries may be supplied with a textbook or may be part of something
like the AP CS case study. If you
want to store such libraries and utility code in one place, follow the set of
instructions for setting up your own library wiht jar files found here
or for setting the CLASSPATH environment
variable.
Chris Nevison
chris@cs.colgate.edu
June 2002