Java Applications

Java Applications

General Steps to Creating, Compiling and Running Java Programs
Applications in Unix & Linux server

1. Open a Unix window.

2. Now, change to the directory of your choice from within the window. 
   For example: 
   

   prompt% cd MyJavaStuff

3. Using the editor of your choice, create some Java source code 
   For example, suppose we want a Java class named "Test", 
       then we would start vi, emacs, pico, or whatever editor you use 
           with the name of the Java file: 
   

   prompt% vi Test.java

   or

   prompt% emacs Test.java

   or

   prompt% pico Test.java

4. The source code, Test.java, might look like this: 
   

   public class Test { public static void main(String args[]) { System.out.println("We work!"); } }

   Don't forget to save the file!

5. Double check the name of the Java program file you just saved 
       by listing out the files in the current directory: 
   

   prompt% ls

6. If the name of the Java program file listed does not end in .java, 
       you need to rename or move (mv) it so that it does 
   For instance, if the file appears as A.java.txt, type

   prompt% mv A.java.txt A.java

   Now if you list the files in the directory, you should see it named correctly

7. Assuming we saved the Java source code (as in step 4) from within our editor, 
       we can now go back to the command prompt and compile it. 
   This is done with the javac compiler command: 
   

   prompt% javac Test.java

8. If it doesn't compile, go back to the editor and edit the A.java file 
       to remove the error. 
   Then repeat step 7 after saving the changes. 
   You may have to do this several times before there are no more compile errors.

9. When it compiles fine 
                   (we know this by the fact we had no error messages 
                   and the "Test.class" file exists), 
   we can run the application (found in Test.class) using the java command 
       followed by the name of the class (without the extension): 
   

   prompt% java Test

10. At this point you should see:
    

    We work!