To compile  a java  program, at the command line
type:<br>javac filename.java<br><br>For example, given the file
MyFirstClass.java<br>which contains:<br>class MyFirstClass<br>{<br> public
static void main(String[] args)<br> {<br>
System.out.println("Hello World");<br> }<br>}<br><br>to compile at the
command line type(case sensitive):<br>javac
MyFirstClass.java<br><br>to run at the command line type:<br>java
MyFirstClass<br><br>and you should see the phrase<br>Hello
World<br><br><br>There is lots of good information at
http://java.sun.com especially the
Java Tutorial section.