How to write “Hello, world!” in Java?

1. Create a package for a class:

   mkdir -p com/farenda/solved
   

2. Create a file com/farenda/solved/HelloWorld.java with content:

   package com.farenda.solved;
   
   public class HelloWorld {
       public static void main(String[] args) {
           System.out.println("Hello, world!");
       }
   }
   

3. Create directory for compiled classes:

   mkdir classes
   

4. Compile source:

   javac src/com/farenda/solved/HelloWorld.java -d classes
   

5. Run compiled code:

   java -cp classes com.farenda.solved.HelloWorld
   

Hello, world!