This chapter describes how to create and run a Java program. It shows the classic "Hello World" program – the program that nearly everyone writes as their first program in a new language.
The previous chapters have discussed computer hardware, computer software, bits and bytes, machine language, language translation, language interpretation, and virtual machines. This chapter assumes that you know all that and are ready to look at Java.
These notes are written for Java Standard Edition version 8.0 or higher. Previous versions may not work as well with these notes. If you are installing Java for the first time on your computer, install the Java Development Kit (JDK) from Oracle.
Easy Way to Run Java: The web site http://ideone.com/ lets you copy-and-paste Java code into a web page text box, then compile and run it completely within your browser. This is ideal for playing with the example programs in many of these chapters. Another web site that does this https://www.codiva.io/
(Review :)Can the processor of a computer system directly execute source programs written in Java?