Compile and Run a Hello-world Java Program

Step 1

 

Open "Folder" and create a new directory called "myproject" under your home directory to keep all your works.

---

Step 2

 

Open "Text Editor" (gedit). Enter the following source code and save as "Hello.java" under the "~/myproject" directory created eariler.

 

    public class Hello {   // To save as "Hello.java" under "~/myproject"

       public static void main(String[] args) {

          System.out.println("Hello, world from Ubuntu!");

       }

    }

---

Step 3

To compile the Hello-world Java program, launch a Terminal and issue these commands:

 

// Change directory to where the source code resides

cd ~/myproject

     

// List the contents of current directory. Check for "Hello.java"

ls

    ...... Hello.java ....

     

// Compile "Hello.java" into "Hello.class"

javac Hello.java

     

// Check for "Hello.class"

ls

    ...... Hello.class ....

---

Step 4

 

Run the Hello-world Java program:

 

// Run "Hello.class"

java Hello

    Hello, world from Ubuntu!

---