Install Oracle Java SE on Oracle Linux

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Install Oracle Java SE on Oracle Linux

Introduction

Oracle's Java Platform , Standard Edition (Java SE ) lets you develop and deploy Java applications on desktops and servers.

The Java Platform Standard Edition Development Kit (JDK) includes tools for developing, testing, and monitoring programs written in the Java programming language and running on the Java platform. The JDK offers developers and users a rich user interface and the performance, versatility, portability, and security that today's applications require.

Beyond these great features, Oracle provides the Oracle JDK free for commercial and production use. When you combine Oracle Java with Oracle's highly performant, reliable, and cloud-ready operating system, Oracle Linux , you get an ideal environment with out-of-the-box optimizations for Oracle software, excellent for running Oracle Java.

Objectives

In this tutorial, you will learn how to:

  • Check for available Oracle Java RPMs
  • Install Oracle Java
  • Verify the JDK version
  • Set the default JDK on a system with multiple versions
  • Run a basic Java "Hello World" program

Prerequisites

  • Minimum of a single Oracle Linux system

  • Each system should have Oracle Linux installed and configured with:

    • A non-root user account with sudo access
    • Access to the Internet

Deploy Oracle Linux

Note: If running in your own tenancy, read the linux-virt-labs GitHub project README.md and complete the prerequisites before deploying the lab environment.

  1. Open a terminal on the Luna Desktop.

  2. Clone the linux-virt-labs GitHub project.

    git clone https://github.com/oracle-devrel/linux-virt-labs.git

  3. Change into the working directory.

    cd linux-virt-labs/ol

  4. Install the required collections.

    ansible-galaxy collection install -r requirements.yml

  5. Deploy the lab environment.

    ansible-playbook create_instance.yml -e localhost_python_interpreter="/usr/bin/python3.6"

    The free lab environment requires the extra variable local_python_interpreter, which sets ansible_python_interpreter for plays running on localhost. This variable is needed because the environment installs the RPM package for the Oracle Cloud Infrastructure SDK for Python, located under the python3.6 modules.

    The default deployment shape uses the AMD CPU and Oracle Linux 8. To use an Intel CPU or Oracle Linux 9, add -e instance_shape="VM.Standard3.Flex" or -e os_version="9" to the deployment command.

    Important: Wait for the playbook to run successfully and reach the pause task. At this stage of the playbook, the installation of Oracle Linux is complete, and the instances are ready. Take note of the previous play, which prints the public and private IP addresses of the nodes it deploys and any other deployment information needed while running the lab.

Check the Availability of Oracle Java

  1. Open a terminal and connect via SSH to the ol-node-01 instance.

    ssh oracle@<ip_address_of_instance>

  2. Check the availability of the Oracle Java packages.

    sudo dnf list jdk*

    When using Oracle Linux in Oracle Cloud Infrastructure (OCI), the Oracle Java packages exist in the ol<version>_oci_included repositories. OCI installs and enables these repositories by default when provisioning an Oracle Linux instance.

    Note: Oracle splits the JDK installation on Oracle Linux into two packages: jdk-<version>-headless and jdk-<version>-headful.

    • jdk-<version>-headless is a headless Java Runtime for running non-GUI applications.

    • jdk-<version>-headful is headful Java Runtime and a set of Development Tools for developing and running all types of applications.

    The jdk-<version>-headful package requires the jdk-<version>-headless package. When installing these packages together, they provide the same functionality as the JDK package Oracle provides for Generic Linux Platforms. See the Installation Guide in the Oracle JDK documentation for more details.

Install Oracle Java

  1. Install one of the Oracle Java versions.

    sudo dnf install -y jdk-22-headful

  2. Confirm the installation by checking the JDK version.

    java -version

    Note: To help ensure that your systems are secure when using Java-based content, Oracle strongly recommends that all Java SE users upgrade to the latest release available for the version you are using.

(Optional) Setting the default JDK on a system with multiple versions

If multiple versions of the JDK exist on an Oracle Linux system, users can set the default version using the alternatives command, which maintains symbolic links that determine default commands. See the update-alternatives(8) manual page for more details.

  1. Install Oracle Java 17.

    sudo dnf install -y jdk-17-headful

  2. Confirm Oracle Java 22 is the default version.

    java -version

  3. Change the default to Oracle Java 17.

    sudo alternatives --config java

    Type 2 and the ENTER key to select Oracle Java 17.

  4. Recheck the version.

    java -version

    Notice the output now shows the version for Oracle Java 17.

  5. Switch the default back to Oracle Java 22.

    sudo alternatives --config java

    Type 1 and the ENTER key to select Oracle Java 22.

Write, Compile, and Run a Java Program

A "Hello, World!" program outputs Hello, World! or a similar welcome message on the screen. The syntax creates a straightforward program and is commonly used to introduce a new programming language to new developers.

  1. Create the Java program.

    tee ~/HelloWorld.java > /dev/null <<'EOF'
class HelloWorld {
  public static void main(String[] args) {
    System.out.println("Hello, World!"); 
  }
}
EOF

  2. Compile the Java program.

    javac HelloWorld.java

  3. Run the Java program.

    java HelloWorld

Next Steps

That completes the tutorial and demonstrates how to install the Oracle Java SE Platform on Oracle Linux and write your first program.

SSR