Java Developer's Guide for Fedora

Purpose

To make Java a friendlier language. To make it easier for beginning and experienced developers to learn and work with Java on Fedora.

Request for Additions and Corrections

Please e-mail me your ideas.

How to Learn Java

Here are some quality learning resources:

• A free on-line and printable book: Think Java: How to Think Like a Computer Scientist by Allen B. Downey
• An on-line course: Introduction to Programming Using Java by David J. Eck
• Video Tutorials at thenewboston

Java is Available from Multiple Vendors

The standard Java platform is implemented by products from multiple vendors:

• OpenJDK is the default for Fedora
• Oracle
• IBM
• GNU Java

OpenJDK is the product backed by the open source community, including Fedora.

Java Version Numbers: Apparently Designed to Produce Customer Confusion

Sun Microsystems, the creators of Java, apparently thought it would be good marketing to refer to the same versions of Java with different numbers.

• 8 = 1.8
• 7 = 1.7
• 6 = 1.6
• 2 = 1.2, 1.3 & 1.4

Where is Java Installed?

/usr/lib/jvm Docs?

Setting the Active Java Runtime

alternatives --config java

Invoking Java Runtime Programs

• java
• javac
• jar

How to Run Java Applications

How you run a Java application depends on how it was packaged and distributed to you. If the packaging was done well, running the application can be as simple as selecting it from a menu on your favorite desktop environment. However, since one of the primary goals of Java is that Java applications should work on any and all operating systems, it is likely that you may receive a Java program that is packaged in a very basic form (for example, a .class or .jar file) that works on all operating systems. This makes it slightly harder to run the application because you have to understand a little bit about how Java works.