Getting Started with Java: Part 1

Overview, Execution, and Installation

What is Java?

Java is a class-based, object-oriented programming language which was developed by James Gosling in 1995 at Sun Microsystems. Today, it is one of the most widely-used programming languages.

How is Java executed?

In Java, programs are run in two phases: compilation and execution.

A program’s source code is first compiled into Java bytecode. Bytecode is simply a set of instructions which are understood by the machine.

Compilation Phase

During execution, the Java bytecode is executed using the Java Runtime Environment (JRE). The JRE is a software bundle that contains resources needed for the program to run, including the Java Virtual Machine (JVM), Java class libraries, and other supporting files. JVM is a runtime engine that converts Java bytecode into machine language.

Execution Phase

The compilation of source code into Java bytecode allows Java to be platform independent. Meaning, you can write a program on Windows and execute it on a Mac (as long as the machine has a JRE).

How do I install Java?

The first step in creating your first Java project is installing the Java Development Kit (JDK). The JDK includes all of the necessary tools to build applications. You will also need a code editor. Popular editors include NetBeans, Eclipse, and IntelliJ. I use the community version (free) of IntelliJ.

What’s next?

In my next post, I will take you through building your first Java project as well as the fundamentals of Java programming.

Resources

• Programming with Mosh: Java Tutorial for Beginners
• Java Docs