How to Install Java on CentOS 8
Java is a free, open-source and one of the most popular programming languages expressly designed for use in the distributed environment of the internet. There are two different implementations of Java, Oracle Java and OpenJDK. Oracle Java has some additional commercial features while OpenJDK is an open-source implementation of the Java Platform.
In this tutorial, we will show you how to install OpenJDK 8, OpenJDK 11 and Oracle 8 on CentOS 8.
Requirements
- A server running CentOS 8.
- A root password is set up on your system.
Install OpenJDK 11
First, search the OpenJDK available versions in the CentOS 8 repository by running the following command:
dnf search jdk
You should see the following output:
Last metadata expiration check: 1:23:41 ago on Wednesday 18 December 2019 02:23:23 AM EST. ========================================================= Summary & Name Matched: jdk ========================================================= java-11-openjdk-demo.x86_64 : OpenJDK Demos 11 java-1.8.0-openjdk-demo.x86_64 : OpenJDK Demos 8 java-11-openjdk-jmods.x86_64 : JMods for OpenJDK 11 java-11-openjdk-src.x86_64 : OpenJDK Source Bundle 11 java-1.8.0-openjdk-src.x86_64 : OpenJDK Source Bundle 8 java-11-openjdk.x86_64 : OpenJDK Runtime Environment 11 copy-jdk-configs.noarch : JDKs configuration files copier java-1.8.0-openjdk.x86_64 : OpenJDK Runtime Environment 8 java-11-openjdk-javadoc.x86_64 : OpenJDK 11 API documentation java-1.8.0-openjdk-javadoc.noarch : OpenJDK 8 API documentation java-11-openjdk-devel.x86_64 : OpenJDK Development Environment 11 java-1.8.0-openjdk-devel.x86_64 : OpenJDK Development Environment 8 java-11-openjdk-headless.x86_64 : OpenJDK Headless Runtime Environment 11 java-1.8.0-openjdk-accessibility.x86_64 : OpenJDK 8 accessibility connector java-1.8.0-openjdk-headless.x86_64 : OpenJDK Headless Runtime Environment 8 java-11-openjdk-javadoc-zip.x86_64 : OpenJDK 11 API documentation compressed in a single archive java-1.8.0-openjdk-javadoc-zip.noarch : OpenJDK 8 API documentation compressed in a single archive ============================================================ Summary Matched: jdk ============================================================= icedtea-web.noarch : Additional Java components for OpenJDK - Java browser plug-in and Web Start implementation
Now, install OpenJDK 11 using the following command:
dnf install java-11-openjdk-devel.x86_64
Once the installation is completed, you can verify the installed Java version by running the following command:
java -version
You should see the following output:
openjdk version "11.0.5" 2019-10-15 LTS OpenJDK Runtime Environment 18.9 (build 11.0.5+10-LTS) OpenJDK 64-Bit Server VM 18.9 (build 11.0.5+10-LTS, mixed mode, sharing)
Install OpenJDK 8
Some Java-based applications only support on OpenJDK 8. In this case, you will need to install OpenJDK 8 on your server. You can install OpenJDK 8 easily with the following command:
dnf install java-1.8.0-openjdk-devel
After installing Java, you can check the installed version of Java with the following command:
java -version
You should see the following output:
openjdk version "1.8.0_232" OpenJDK Runtime Environment (build 1.8.0_232-b09) OpenJDK 64-Bit Server VM (build 25.232-b09, mixed mode)
Switch Between Java Versions
You can also install the multiple versions of Java in a single system and switch between them as per your requirements.
You can run the following command to switch the Java version from OpenJDK 8 to OpenJDK 11 as shown below:
alternatives --config java
You will be asked to provide your desired Java version as shown below:
There are 2 programs which provide 'java'. Selection Command ----------------------------------------------- 1 java-11-openjdk.x86_64 (/usr/lib/jvm/java-11-openjdk-11.0.5.10-0.el8_0.x86_64/bin/java) *+ 2 java-1.8.0-openjdk.x86_64 (/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.232.b09-0.el8_0.x86_64/jre/bin/java) Enter to keep the current selection[+], or type selection number: 1
Type 1 and hit Enter to switch the Java version.
After change again check the current active Java version with the following command:
java -version
Install Oracle Java 8
First, you will need to log in the Oracle Java website and go to the Oracle Java 8 JDK Downloads Page. Next, accept the license agreement and download the jdk-8u231-linux-x64.rpm package.
Once the download is completed, run the following command to install Oracle OpenJDK 8:
dnf localinstall jdk-8u231-linux-x64.rpm
After installing Oracle OpenJDK 8, you can verify the Java version with the following command:
java -version
You should see the following output:
java version "1.8.0_231" Java(TM) SE Runtime Environment (build 1.8.0_231-b11) Java HotSpot(TM) 64-Bit Server VM (build 25.231-b11, mixed mode)
Conclusion
That's it for now. We learned how to install the different versions of Java in CentOS 8. You can now easily install your desired Java version and switch between them as per your requirements.
