Java Programming Guide...........................
You should have already installed Java Development Kit (JDK).
Let us begin by writing our first Java program that prints a message "Hello, world!" to the display console, as follows:
Step 1: Write the Source Code: Enter the following source codes using a programming text editor (such as TextPad or NotePad++ for Windows or gedit for UNIX/Lunix/Mac) or an Interactive Development Environment (IDE) (such as Eclipse or Netbeans - Read the respective "How-To" article on how to install and get started with these IDEs).