As a Java developer, you will need to install it on your system one time or the other. Contrary to popular belief, it is pretty simple to install Java on your Ubuntu machine. In this article, we will explain the following three ways to install a stable version of Java on your Ubuntu system:
- Through OpenJDK binaries
- Installation Via PPA
- Through official Oracle Java website
The steps and commands described in this article have been run on an Ubuntu 18.04 LTS system.
Java Installation through OpenJDK binaries
The simplest and quickest way to install Java on your Ubuntu system is through Ubuntu’s repository. This way you can install a stable version of Java through the open source Java runtime binaries called the OpenJDK
Open your Ubuntu Terminal either through the Dash or the Ctrl+alt+T shortcut.
Enter the following command as root in order to install execute of Java OpenJDK version 11:
$ sudo apt install openjdk-11-jdk
Java will be installed on your system and ready for use. You can confirm installation and check the installed version through the following command:
$ java -version
Or
$ java --version
For execute of Java OpenJDK version 9, you can use the following command:
$ sudo apt install openjdk-9-jdk
Java Installation Via PPA
You can also install Java on your system by using PPA repositories maintained by Webupd8 Team. Enter this command in your Terminal as sudo to add the PPA repository:
$ sudo add-apt-repository ppa:webupd8team/java
Then you need to update your Ubuntu repositories through the following command:
$ sudo apt update
Finally, use the following command in order to install Java through the added repository:
$ sudo apt install oracle-java8-set-default
During installation, you will be required to agree to the license agreement through the following message:
Press Enter for selecting Ok after which the following message will appear:
Select Yes and then press Enter to continue installation. After the installation is complete, you can verify the installation and version information as follows:
$ java -version
Or
$ java --version
Installation through official Oracle Java website
Another way to install Java is by downloading a Java install package from the official Java website:
https://www.oracle.com/technetwork/java/javase/downloads/index.html
From the list of available versions, you can browse to the version you need and then click the Download button:
I am interested in Java SE Development Kit 11.
Select the Accept License Agreement option and then download the dk-11_linux-x64_bin.tar.gz package.
Select the Save File option after which the .tar.gz file will be saved to the Downloads folder.
Copy this file to your Home folder and then run the following command in order to install through this package:
sudo tar -C /opt/java-jdk -zxf ~/jdk-11_linux-x64_bin.tar.gz
The downloaded version of Java will be installed on your system. You can verify the installation through the following command:
$ java -version
Or
$ java --version
Setting a Default Version from all the Installed Java Versions
If you have multiple version of Java installed on your Ubuntu, you can select one as your default one:
First, let us get a list of installed Java versions through the following command:
$ sudo update-alternatives --get-selections | grep java
On my system, the current version of Java is Java 8 and Java 11 is also available for use:
The following command lets you configure a different version of Java as default:
$ sudo update-alternatives --config java
In the following image, you can see that a Selection number is assigned to each version of Java. The asterisk ‘*’ with selection number 2 shows that Java 8 is the currently configured default option.
You can enter a different selection number for respective Java version and then press Enter. Your default version of Java will then be updated with the selection you make here. You can verify is by running the ‘java -version’ command.
Through this article, you have learned three ways to install Java through the command line. You can also install multiple versions of Java but set one as a default version through the procedure described in this article.
