Java 17 Recipes

1-1. Installing Java
 Problem
You want to install Java and experiment with the language.

---

2
 Solution
Install Java Development Kit 17 (JDK), which provides the language and a compiler.
Nothing runs without Java. The runtime environment (JRE) lets you execute Java. 
The JDK lets you compile Java sources into executable classes. There are two main 
distributions: Oracle JDK and OpenJDK. We chose the second one under the GNU 
General Public License because the Oracle JDK license changed for releases starting 
in April 2019, permitting only certain uses at no cost. However, you can download the 
commercial builds of JDK from Oracle under a non-open-source license at the Oracle 
Technology Network.
Download the OpenJDK release for your platform from 
https://jdk.java.net/17/
, 
shown in Figure 
1-1
and extract the archive file on your PC.
Figure 1-1. OpenJDK 17 home page
ChApteR 1 GettInG StARted wIth JAvA 17

---

3
 How It Works
Java is a trademark owned by the Oracle Corporation. The language itself is open source, 
and its evolution is controlled by the Java Community Process (JCP). You can read about 
it at 
www.jcp.org/en/home/index
. While Oracle Corporation does not own the language, 
its core development tends to be steered by that company. It is Oracle Corporation that 
runs the JCP and owns the jcp.org domain.
The Java home folder has the bin subfolder that help you to develop and execute 
programs in Java language (with tools and utilities) and that supports the execution of 
programs written in the Java programming language (with an implementation of the Java 
Runtime Environment (JRE), class libraries, and other files). Since Java 11, Oracle and 
the OpenJDK team decided to distribute only the JDK and stop duplicating some of the 
things in JDK in the JRE folder.
There are many editions of Java, such as the Mobile Edition (ME) (
www.oracle.com/
java/technologies/javameoverview.html
) and the Enterprise Edition (EE)
(
www.oracle.com/it/java/technologies/java- ee- glance.html
). Java SE is the 
Standard Edition and represents the heart of the language. We built the recipes in this 
book for Java SE programmers. Those interested in developing embedded applications 
for devices may be interested in learning more about Java ME. Similarly, those interested 
in developing web applications and working with enterprise solutions may be interested 
in learning more about Java EE.
OpenJDK and Oracle JDK binaries are compatible and close to each other, but there 
are some differences.
• Oracle JDK source code includes the following text: “ORACLE 
PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.”
The OpenJDK refers to the GPL license terms.
• The output of Java the version in Oracle JDK includes the Oracle- 
specific identifier. OpenJDK does not include the Oracle-specific 
identifier.
• Oracle JDK uses the Java Cryptography Extension (JCE) Code Signing 
Certificate. OpenJDK allows unsigned third-party crypto providers.
• OpenJDK is offered only as a compressed archive. Oracle JDK offers 
installers.
ChApteR 1 GettInG StARted wIth JAvA 17

---

4
Go to 
www.oracle.com/java/technologies/javase/17- relnote- issues.html
for 
more information on the Oracle JDK.