Objective
The objective is to write, compile and execute a basic Hello World java example program.
Requirements
The only requirement is installed java on your Linux system.
Conventions
- # – requires given linux commands to be executed with root privileges either directly as a root user or by use of
sudocommand - $ – given linux commands to be executed as a regular non-privileged user
Instructions
Check your Java Installation
Before you begin make sure that you already have Java installed on your system. The easiest way to confirm the Java installation is to check java version.
Write Java Hello World Program
The first step is to write simple Hello World Java program. Using any text editor create a new file HelloWorld.java with the following content:
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello World");
}
}
Once ready the HelloWorld.java program should be located in your current working directory:
$ ls HelloWorld.java HelloWorld.java
Compile Java Program
Now that the coding part is behind us, the next step is to compile the Java Hello World program using the javac command line compiler. Open up terminal and enter:
$ javac HelloWorld.java
The above command should not produce any output and errors. The result will be a new Java HelloWorld.class file located within your current working directory:
$ ls HelloWorld.class HelloWorld.java
Run Java Program
The last step is to execute the newly compiled java program. To do so we run the java command with a single parameter which will be the name of our class HelloWorld:
$ java HelloWorld Hello World
