How to Download JDK 8 on Red Hat Enterprise Linux

If you are a Java developer or enthusiast, you probably know that Java Development Kit (JDK) is a software package that provides you with the tools and libraries to create and run Java applications. JDK includes a Java compiler, a Java runtime environment (JRE), a debugger, a documentation generator, and other utilities.

One of the most popular versions of JDK is JDK 8, which was released in March 2014 and is still widely used today. JDK 8 introduced many new features and enhancements, such as lambda expressions, streams, default methods, date and time API, Nashorn JavaScript engine, and more.

If you want to use JDK 8 on your system, you need to download and install it first. In this article, we will show you how to do that on Red Hat Enterprise Linux (RHEL), which is a leading enterprise Linux platform that offers stability, security, performance, and innovation for various workloads.

Prerequisites

Before you start downloading and installing JDK 8 on RHEL, you need to make sure that your system meets the following requirements:

You have a RHEL system with a supported architecture (x86_64 or aarch64).
You have at least 1 GB of free disk space.
You have root or sudo access to your system.
You have a valid Red Hat subscription and your system is registered to access the software repositories.

If you don’t have a Red Hat subscription yet, you can get one for free as a developer or as an individual user. You can also try RHEL for free for up to 16 systems.

To register your system, you can use the Subscription Manager tool or the web console. For more details, see the RHEL documentation.

Installation methods

There are two main methods to install JDK 8 on RHEL: using the .rpm package or using the .tar.gz archive. We will explain both methods in this section.

Using the .rpm package

The easiest way to install JDK 8 on RHEL is to use the .rpm package provided by Red Hat. This package is available from the Red Hat Customer Portal or the Red Hat Developer website.

To download and install the .rpm package of JDK 8 from the Red Hat Customer Portal, follow these steps:

Log in to the Red Hat Customer Portal with your credentials.
Navigate to Downloads > Red Hat build of OpenJDK.
Click Accept License Agreement.
Under the Download menu, click the Download link that corresponds to the .rpm file for your version of RHEL and architecture.
Save the file to your desired location on your system.
Open a terminal and navigate to the directory where you saved the file.
Run the following command to install the package:

sudo yum install java-1.8.0-openjdk-1.8.0.*-redhat.x86_64.rpm

To download and install the .rpm package of JDK 8 from the Red Hat Developer website, follow these steps:

Log in to the Red Hat Developer website with your credentials.
Navigate to Products > Red Hat build of OpenJDK.
Click Download.
Select your version of RHEL and architecture from the drop-down menus.
Click Download next to the .rpm file.
Save the file to your desired location on your system.
Open a terminal and navigate to the directory where you saved the file.
Run the following command to install the package:

sudo yum install java-1.8.0-openjdk-1.8.0.*-redhat.x86_64.rpm

Using the .tar.gz archive

An alternative way to install JDK 8 on RHEL is to use the .tar.gz archive provided by Oracle. This archive contains the binary files of JDK 8 that you can extract and use on your system.

To download and extract the .tar.gz archive of JDK 8 from the Oracle website, follow these steps:

Go to the Oracle Java SE Downloads page.
Under Java SE 8uXXX, where XXX is the latest update number, click JDK Download.
Select your version of RHEL and architecture from the table and click Download.
Accept the license agreement and save the file to your desired location on your system.
Open a terminal and navigate to the directory where you saved the file.
Run the following command to extract the archive:

tar xvf jdk-8uXXX-linux-x64.tar.gz

This will create a directory named jdk1.8.0_XXX, where XXX is the update number, in your current directory.

To use JDK 8 on your system, you need to set up some environment variables, such as JAVA_HOME, JRE_HOME, and PATH. You can do this by editing your .bashrc file or creating a script in /etc/profile.d/. For example, you can add the following lines to your .bashrc file:

# Set JAVA_HOME export JAVA_HOME=/path/to/jdk1.8.0_XXX # Set JRE_HOME export JRE_HOME=$JAVA_HOME/jre # Add Java bin directory to PATH export PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin

You need to replace /path/to/jdk1.8.0_XXX with the actual path of your JDK 8 directory. You also need to source your .bashrc file or log out and log in again for the changes to take effect.

Verification and testing

To verify that JDK 8 is installed correctly on your system, you can use some commands to check its version and location.

Verifying the installation

To check the version of JDK 8 on your system, run the following command:

java -version

You should see an output similar to this:

openjdk version "1.8.0_XXX" OpenJDK Runtime Environment (build 1.8.0_XXX-redhat-bXX) OpenJDK 64-Bit Server VM (build 25.XXX-bXX, mixed mode)

The output may vary depending on whether you installed JDK 8 from Red Hat or Oracle, but it should indicate that you are using JDK 8.

To check the location of JDK 8 on your system, run the following command:

which java

You should see an output similar to this:

/usr/bin/java

This is the symbolic link that points to the actual location of JDK 8 on your system. To find out where it points to, run the following command:

readlink -f /usr/bin/java

You should see an output similar to this:

/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.XXX-redhat.x86_64/jre/bin/java

This is the actual location of JDK 8 on your system. You can also use the $JAVA_HOME environment variable to get the same information.

Testing the functionality

To test the functionality of JDK 8 on your system, you can try to compile and run a simple Java program using JDK 8. For example, you can create a file named HelloWorld.java with the following content:

public class HelloWorld {     public static void main(String[] args) {         System.out.println("Hello, world!");     } }

To compile this program, run the following command:

javac HelloWorld.java

This will create a file named HelloWorld.class, which is the bytecode of your program.

To run this program, run the following command:

java HelloWorld

You should see an output like this:

Hello, world!

This means that JDK 8 is working properly on your system and you can start developing and running Java applications using JDK 8.

Conclusion

In this article, we have shown you how to download and install JDK 8 on Red Hat Enterprise Linux using two methods: using the .rpm package or using the .tar.gz archive. We have also shown you how to verify and test the installation of JDK 8 on your system.

JDK 8 is one of the most popular and widely used versions of Java Development Kit that provides many new features and enhancements for Java development. By installing JDK 8 on RHEL, you can benefit from the stability, security, performance, and innovation of both platforms.

If you want to learn more about JDK 8 or RHEL, you can check out the following resources:

Frequently Asked Questions

How do I update JDK 8 on RHEL?

If you installed JDK 8 from Red Hat using the .rpm package, you can update it using the yum update command or the web console. If you installed JDK 8 from Oracle using the .tar.gz archive, you need to download and extract the latest version of the archive and update the environment variables accordingly.

How do I uninstall JDK 8 from RHEL?

If you installed JDK 8 from Red Hat using the .rpm package, you can uninstall it using the yum remove command or the web console. If you installed JDK 8 from Oracle using the .tar.gz archive, you can simply delete the directory where you extracted it and remove any references to it from your environment variables.

How do I switch between different versions of JDK on RHEL?

If you have multiple versions of JDK installed on your system, you can use the alternatives command or the web console to switch between them. For example, to switch to JDK 8, run the following command:

sudo alternatives --config java

This will show you a list of available Java versions and ask you to enter a number to select one. Enter the number that corresponds to JDK 8 and press Enter.

How do I set up Java development tools on RHEL?

If you want to use Java development tools such as IDEs, debuggers, testing frameworks, etc., you need to install them separately from JDK. You can use yum install

to install the tools from the Red Hat software repositories, or download and install them from their official websites. Some of the popular Java development tools are Eclipse, NetBeans, IntelliJ IDEA, Maven, Gradle, JUnit, etc.

How do I troubleshoot JDK 8 issues on RHEL?

If you encounter any issues with JDK 8 on RHEL, you can try the following steps to troubleshoot them:

Check the logs and error messages for any clues.
Verify that your system meets the requirements and that JDK 8 is installed correctly.
Update JDK 8 to the latest version and apply any patches or fixes.
Check the Red Hat Knowledgebase or the Oracle Java SE Support for any known issues or solutions.
Contact Red Hat Support or Oracle Support for further assistance.

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