How To Install Java with Apt on Ubuntu 20.04

Updated on August 31, 2021
How To Install Java with Apt on Ubuntu 20.04
Not using Ubuntu 20.04?Choose a different version or distribution.
Ubuntu 20.04


Java and the JVM (Java’s virtual machine) are required for many kinds of software, including Tomcat, Jetty, Glassfish, Cassandra and Jenkins.

In this guide, you will install various versions of the Java Runtime Environment (JRE) and the Java Developer Kit (JDK) using apt. You’ll install OpenJDK as well as the official JDK from Oracle. You’ll then select the version you wish to use for your projects. When you’re finished, you’ll be able to use the JDK to develop software or use the Java Runtime to run software.


To follow this tutorial, you will need:

Installing the Default JRE/JDK

The easiest option for installing Java is to use the version packaged with Ubuntu. By default, Ubuntu 20.04 includes Open JDK 11, which is an open-source variant of the JRE and JDK.

To install this version, first update the package index:

  1. sudo apt update

Next, check if Java is already installed:

  1. java -version

If Java is not currently installed, you’ll see the following output:

Command 'java' not found, but can be installed with: sudo apt install openjdk-11-jre-headless # version 11.0.11+9-0ubuntu2~20.04, or sudo apt install default-jre # version 2:1.11-72 sudo apt install openjdk-13-jre-headless # version 13.0.7+5-0ubuntu1~20.04 sudo apt install openjdk-16-jre-headless # version 16.0.1+9-1~20.04 sudo apt install openjdk-8-jre-headless # version 8u292-b10-0ubuntu1~20.04

Execute the following command to install the default Java Runtime Environment (JRE), which will install the JRE from OpenJDK 11:

  1. sudo apt install default-jre

The JRE will allow you to run almost all Java software.

Verify the installation with:

  1. java -version

You’ll see output similar to the following:

openjdk version "11.0.11" 2021-04-20 OpenJDK Runtime Environment (build 11.0.11+9-Ubuntu-0ubuntu2.20.04) OpenJDK 64-Bit Server VM (build 11.0.11+9-Ubuntu-0ubuntu2.20.04, mixed mode, sharing))

You may need the Java Development Kit (JDK) in addition to the JRE in order to compile and run some specific Java-based software. To install the JDK, execute the following command, which will also install the JRE:

  1. sudo apt install default-jdk

Verify that the JDK is installed by checking the version of javac, the Java compiler:

  1. javac -version

You’ll see the following output:

javac 11.0.11

Next, let’s look at how to install Oracle’s official JDK and JRE.

Installing Oracle JDK 11

Oracle’s licensing agreement for Java doesn’t allow automatic installation through package managers. To install the Oracle JDK, which is the official version distributed by Oracle, you must create an Oracle account and manually download the JDK to add a new package repository for the version you’d like to use. Then you can use apt to install it with help from a third party installation script.

The version of Oracle’s JDK you’ll need to download must match version of the installer script. To find out which version you need, visit the oracle-java11-installer page.

Locate the package for Focal, as shown in the following figure:

Installer package for Ubuntu 20.04

In this image, the version of the script is 11.0.7. In this case, you would need Oracle JDK 11.0.7. Your version number may vary depending on when you’re installing the software.

You don’t need to download anything from this page; you’ll download the installation script through apt shortly.

Then visit the Downloads page and locate the version that matches the one you need.

Oracle Java 11

Click the JDK Download button and you’ll be taken to a screen that shows the versions available. Click the .tar.gz package for Linux.

Linux download

You’ll be presented with a screen asking you to accept the Oracle license agreement. Select the checkbox to accept the license agreement and press the Download button. Your download will begin. You may need to log in to your Oracle account one more time before the download starts.

Once the file has downloaded, you’ll need to transfer it to your server. On your local machine, upload the file to your server. On macOS, Linux, or Windows using the Windows Subsystem for Linux, use the scp command to transfer the file to the home directory of your sammy user. The following command assumes you’ve saved the Oracle JDK file to your local machine’s Downloads folder:

  1. scp Downloads/jdk-11.0.7_linux-x64_bin.tar.gz sammy@your_server_ip:~

Once the file upload has completed, return to your server and add the third-party repository that will help you install Oracle’s Java.

Install the software-properties-common package, which adds the add-apt-repository command to your system:

  1. sudo apt install software-properties-common

Next, import the signing key used to verify the software you’re about to install:

  1. sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys EA8CACC073C3DB2A

You’ll see this output:

gpg: key EA8CACC073C3DB2A: public key "Launchpad PPA for Linux Uprising" imported gpg: Total number processed: 1 gpg: imported: 1

Then use the add-apt-repository command to add the repo to your list of package sources:

  1. sudo add-apt-repository ppa:linuxuprising/java

You’ll see this message:

Oracle Java 11 (LTS) and 16 installer for Ubuntu (21.04, 20.10, 20.04, 18.04, 16.04 and 14.04), Pop!_OS, Linux Mint and Debian. Java binaries are not hosted in this PPA due to licensing. The packages in this PPA download and install Oracle Java, so a working Internet connection is required. The packages in this PPA are based on the WebUpd8 Oracle Java PPA packages: https://launchpad.net/~webupd8team/+archive/ubuntu/java Created for users of https://www.linuxuprising.com/ Installation instructions (with some tips), feedback, suggestions, bug reports etc.: . . . Press [ENTER] to continue or Ctrl-c to cancel adding it.

Press ENTER to continue the installation. You may see a message about no valid OpenPGP data found, but you can safely ignore this.

Update your package list to make the new software available for installation:

  1. sudo apt update

The installer will look for the Oracle JDK you downloaded in /var/cache/oracle-jdk11-installer-local. Create this directory and move the Oracle JDK archive there:

  1. sudo mkdir -p /var/cache/oracle-jdk11-installer-local/
  2. sudo cp jdk-11.0.7_linux-x64_bin.tar.gz /var/cache/oracle-jdk11-installer-local/

Finally, install the package:

  1. sudo apt install oracle-java11-installer-local

The installer will first ask you to accept the Oracle license agreement. Accept the agreement, then the installer will extract the Java package and install it.

Now let’s look at how to select which version of Java you want to use.

Managing Java

You can have multiple Java installations on one server. You can configure which version is the default for use on the command line by using the update-alternatives command.

  1. sudo update-alternatives --config java

This is what the output would look like if you’ve installed both versions of Java in this tutorial:

There are 2 choices for the alternative java (providing /usr/bin/java). Selection Path Priority Status ------------------------------------------------------------ 0 /usr/lib/jvm/java-11-openjdk-amd64/bin/java 1111 auto mode 1 /usr/lib/jvm/java-11-openjdk-amd64/bin/java 1111 manual mode * 2 /usr/lib/jvm/java-11-oracle/bin/java 1091 manual mode Press <enter> to keep the current choice[*], or type selection number:

Choose the number associated with the Java version to use it as the default, or press ENTER to leave the current settings in place.

You can do this for other Java commands, such as the compiler (javac):

  1. sudo update-alternatives --config javac

Other commands for which this command can be run include, but are not limited to: keytool, javadoc and jarsigner.

Setting the JAVA_HOME Environment Variable

Many programs written using Java use the JAVA_HOME environment variable to determine the Java installation location.

To set this environment variable, first determine where Java is installed. Use the update-alternatives command:

  1. sudo update-alternatives --config java

This command shows each installation of Java along with its installation path:

There are 2 choices for the alternative java (providing /usr/bin/java). Selection Path Priority Status ------------------------------------------------------------ 0 /usr/lib/jvm/java-11-openjdk-amd64/bin/java 1111 auto mode 1 /usr/lib/jvm/java-11-openjdk-amd64/bin/java 1111 manual mode * 2 /usr/lib/jvm/java-11-oracle/bin/java 1091 manual mode Press <enter> to keep the current choice[*], or type selection number:

In this case the installation paths are as follows:

  1. OpenJDK 11 is located at /usr/lib/jvm/java-11-openjdk-amd64/bin/java.
  2. Oracle Java is located at /usr/lib/jvm/java-11-oracle/jre/bin/java.

Copy the path from your preferred installation. Then open /etc/environment using nano or your favorite text editor:

  1. sudo nano /etc/environment

At the end of this file, add the following line, making sure to replace the highlighted path with your own copied path, but do not include the bin/ portion of the path:


Modifying this file will set the JAVA_HOME path for all users on your system.

Save the file and exit the editor.

Now reload this file to apply the changes to your current session:

  1. source /etc/environment

Verify that the environment variable is set:

  1. echo $JAVA_HOME

You’ll see the path you just set:


Other users will need to execute the command source /etc/environment or log out and log back in to apply this setting.


In this tutorial you installed multiple versions of Java and learned how to manage them. You can now install software which runs on Java, such as Tomcat, Jetty, Glassfish, Cassandra or Jenkins.

Get Ubuntu on a hosted virtual machine in seconds with DigitalOcean Droplets! Simple enough for any user, powerful enough for fast-growing applications or businesses.

Learn more here

About the authors

Still looking for an answer?

Ask a questionSearch for more help

Was this helpful?

This textbox defaults to using Markdown to format your answer.

You can type !ref in this text area to quickly search our full set of tutorials, documentation & marketplace offerings and insert the link!

Thank you for writing this article, helpful :)

I kept getting the error mentioned here: sha256sum mismatch. When I ran the recommended command: sudo rm /var/lib/dpkg/info/oracle-java11-installer-local.postinst -f, I was finally able to follow your tutorial. So, I would echo the complimentary comments if you’re starting from scratch, but I had already attempted to install Java 11

How do you figure out the recv-keys is EA8CACC073C3DB2A?

[…] Next, import the signing key used to verify the software you’re about to install:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys EA8CACC073C3DB2A

Thank you !

This is by far the best and most complete HowTo I have ever found on this topic. Great job Brian!

The only thing that is missing is the relation between the java versions and the javaws binary.
On my windows laptop running ‘javaws’ in a terminal gives me an info popup showing ‘Java Web Start’ (i assume that’s the version). When i do the same on my Ubuntu 20.04 VM i get ‘Java™ Web Start 1.6.0_45’

I know that the java version numbers are a bit special (how is that for an understatement ?! ;-) but i just cant get my head around the output i get from javaws.

Any ideas ?

Try DigitalOcean for free

Click below to sign up and get $200 of credit to try our products over 60 days!

Sign up

Join the Tech Talk
Success! Thank you! Please check your email for further details.

Please complete your information!

Featured on Community

Get our biweekly newsletter

Sign up for Infrastructure as a Newsletter.

Hollie's Hub for Good

Working on improving health and education, reducing inequality, and spurring economic growth? We'd like to help.

Become a contributor

Get paid to write technical tutorials and select a tech-focused charity to receive a matching donation.

Welcome to the developer cloud

DigitalOcean makes it simple to launch in the cloud and scale up as you grow — whether you're running one virtual machine or ten thousand.

Learn more
DigitalOcean Cloud Control Panel