Compiling and running a Java project from Windows command line.

EXAMPLE 1
-----------

1. Simple java hello world HelloJar.jar file made from HelloJar.java:
---------------------------------------------------------------------

package helloJarPack;

public class HelloJar {
	
    public static void printHelloFromJar(){
		
        System.out.println("Hello from HelloJar.jar");
		
    }

}


2. HelloUsingHelloJar.java file that references jar/library HelloJar.jar
----------------------------------------------------------------------------

import helloJarPack.HelloJar;

public class HelloUsingHelloJar {

    public static void main(String[] args){

        HelloJar.printHelloFromJar();

    }

}


3. Folder structure and commands
------------------------------------

Only one folder is used, it contains HelloUsingHelloJar.java and HelloJar.jar.
Inside this folder open cmd prompt.
(inside folder hold shift and right click, select "Open Command Window Here")


javac -cp HelloJar.jar HelloUsingHelloJar.java (enter) 

java -cp .;HelloJar.jar HelloUsingHelloJar (enter)


You should see "Hello from HelloJar.jar" printed in the console.
The first command creates the HelloUsingHelloJar.class file and puts it in the folder.
(-cp stands for class path)




EXAMPLE 2
------------

This example uses a more complex file structure staring with a root level folder
called FolderOne:

FolderOne 
    |
    |--bin
    |
    |
    |--lib
    |   |
    |   |--HelloJar.jar
    |
    |--src
        |
        |--helloPack
              |
              |--example
                   |
                   |--HelloUsingHelloJar.java



Inside this folder open cmd prompt and type this command then press enter:

javac -d bin -sourcepath src -cp .;lib/HelloJar.jar src/helloPack/example/HelloUsingHelloJar.java

(-d directs the file to the bin folder, if using Linux instead of windows replace ";" with ":")


This creates the HelloUsingHelloJar.class file and the file structure /helloPack/example/ and puts it in the bin folder.
Now the file tree should look like this:



FolderOne 
    |
    |--bin
    |   |
    |   |--helloPack
    |          |
    |          |--example
    |               |
    |               |--HelloUsingHelloJar.class
    |
    |--lib
    |   |
    |   |--HelloJar.jar
    |
    |--src
        |
        |--helloPack
               |
               |--example
                    |
                    |--HelloUsingHelloJar.java



Now run this command:

java -cp bin;lib/HelloJar.jar helloPack.example.HelloUsingHelloJar



You should see "Hello from HelloJar.jar" printed in the console.