1. First take the copy of Java in c: directory. Let the directory name is "Jdk1.3". The main files stored in bin is sub directory of Jdk1.3.
2. Click on Start > Run. Type cmd and click Ok bottom. It will open the Command Prompt of windows.
3. Type edit AUTOEXEC.BAT on Command Prompt.
4. Add a new line in the autoexec.bat file, such as, PATH=%PATH%;C:\jdk1.3\bin;I:\jdk1.3\myproject; myproject is a directory where all java programs stored. Save and close the file. Restart the computer to set the PATH.
5. Type Cd c:\jdk1.3\myproject.
6. Type javac to get help information.
7. Type javac app.java command to compile you program.
8. Type Java app command to run you program.
Note: The file name of Java program must be had .java extension.
public class app
public static void main(String args)
System.out.println("Hello from JAVA!");
Basic Skill: Finding Java classes with CLASSPATH:
You can set the CLASSPATH environment variable to include that directory. By default, there are no paths or directories in CLASSPATH , but you can add a semicolon - separated list to CLASSPATH like this one for windows.
C:\> SET CLASSPATH=c:\classes;c:\newclasses;%CLASSPATH %
Now the java compiler (and other java tools) will know enough to search c:\classes and c:\newclasses automatically. That means that this code will now work if printer.class (own class) is in c:\classes, because that directory is in CLASSPATH.
Note: CLASSPATH is very important while we compile java program. Remember after compiling a written program in java it creates a .class file which must be stored in that directory which set at CLASSPATH.