Chapter 2. Installing OpenJDK

The following sections describe how to install OpenJDK on Microsoft Windows and Red Hat Enterprise Linux (RHEL).

2.1. Installing OpenJDK on Windows

The following section describes how to install OpenJDK 11 on Windows using the MSI-based installer.

Procedure

  1. Download the MSI-based Installer from the Red Hat Developer Portal.
  2. Run the installer and follow the on-screen installation instructions.
  3. Configure CodeReady Studio to use OpenJDK by following the instructions for Working with Java Runtime Environments.

2.1.1. Additional resources

2.2. Installing OpenJDK on RHEL

The following section describes how to install OpenJDK 11 on RHEL.

Prerequisites

Procedure

  • To install OpenJDK RPMs, run:

    # yum install java-11-openjdk-devel

Optionally, you can install the java-11-openjdk-src and the java-11-openjdk-demo packages. The java-11-openjdk-src package contains the complete OpenJDK 11 class library source code you can use with IDE indexers and debuggers. The java-11-openjdk-demo package contains Java runtimes for OpenJDK (demos and examples).

  • To install java-11-openjdk-demo and java-11-openjdk-src, run:

    # yum install java-11-openjdk-src java-11-openjdk-demo

Troubleshooting

If you encounter the following error message while attempting to log in to the OpenShift cluster, configure your Java to use TLSv1.2. This problem only occurs in Java JDK versions prior to Java 11.0.7 and OpenShift cluster 4.4.0 or higher.

Unable to execute request to request url https://<openshift-cluster-oauth-authorization-server>

  • To configure Java to use TLSv1.2:

    1. Open the file codereadystudio.ini located in the studio directory inside of the CodeReady Studio installation directory.
    2. Add the following line under the -vmargs section:

      `-Djdk.tls.client.protocols=TLSv1.2`

2.2.1. Additional resources