Introduction to the Java
Welcome to Java 8. We may be welcoming you back. You may be coming to this eco‐
system from another language, or maybe this is your first programming language.
Whatever road you may have traveled to get here: welcome. We're glad you've
Java is a powerful, general-purpose programming environment. It is one of the most
widely used programming languages in the world, and has been exceptionally suc‐
cessful in business and enterprise computing.
In this chapter, we'll set the scene by describing the Java language (which program‐
mers write their applications in), the Java Virtual Machine (which executes those
applications), and the Java ecosystem (which provides a lot of the value of the pro‐
gramming environment to development teams).
We'll briefly cover the history of the Java language and virtual machine, before mov‐
ing on to discuss the lifecycle of a Java program and clear up some common ques‐
tions about the differences between Java and other environments.
At the end of the chapter, we'll introduce Java security, and discuss some of the
aspects of Java which relate to secure coding.
The Language, the JVM, and the Ecosystem
The Java programming environment has been around since the late 1990s. It com‐
prises the Java language, and the supporting runtime, otherwise known as the Java
Virtual Machine (JVM).
At the time that Java was initially developed, this split was considered novel, but
recent trends in software development have made it more commonplace. Notably,