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How to install Java on Ubuntu 22.04 ?


Install Java on Ubuntu 22.04

Objective

Java is one of the most famous language in the world. Its wide adoption in the past years makes it an unavoidable language in the development world. To have more information and the capabilities of the Java language see the official documentation.

In this tutorial you will learn how to install a Java Development Kit (JDK) on the Ubuntu 22.04 Linux distribution.

 

Requirements

This tutorial assume that you have an Ubuntu 22.04, running in an OVHcloud Compute Instance for example, and some basic knowledge of how to operate it. If you don’t have a running Ubuntu 22.04, follow the guide to use an OVHcloud Compute Instance.

 

Instructions

This tutorial uses OpenJDK version. This is the open source version but there are many licensed versions provided by vendors (Oracle, Microsoft, AWS, …).

In this tutorial, you will, first, install a JDK, then you will use it and to finish you learn how to switch between different installed versions.

At the time of writing this tutorial, the last LTS release of Java is 17.x and the last GA release is 18.x.

 

Installation of the OpenJDK LTS version

To install Java on Ubuntu, the easiest way is to use apt-get command:

sudo apt-get update && apt-get -y install openjdk-17-jdk

Output should be like this:

$ sudo apt-get update && apt-get -y install openjdk-17-jdk
Hit:1 http://security.ubuntu.com/ubuntu jammy-security InRelease
Hit:2 http://nova.clouds.archive.ubuntu.com/ubuntu jammy InRelease
Hit:3 http://nova.clouds.archive.ubuntu.com/ubuntu jammy-updates InRelease
Hit:4 http://nova.clouds.archive.ubuntu.com/ubuntu jammy-backports InRelease
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following additional packages will be installed:
  adwaita-icon-theme alsa-topology-conf alsa-ucm-conf at-spi2-core ca-certificates-java dconf-gsettings-backend dconf-service fontconfig fontconfig-config
  fonts-dejavu-core fonts-dejavu-extra gsettings-desktop-schemas gtk-update-icon-cache hicolor-icon-theme humanity-icon-theme java-common libasound2 libasound2-data
  libatk-bridge2.0-0 libatk-wrapper-java libatk-wrapper-java-jni libatk1.0-0 libatk1.0-data libatspi2.0-0 libavahi-client3 libavahi-common-data libavahi-common3
  libcairo-gobject2 libcairo2 libcups2 libdatrie1 libdconf1 libdeflate0 libdrm-amdgpu1 libdrm-intel1 libdrm-nouveau2 libdrm-radeon1 libfontconfig1 libfontenc1
  libgail-common libgail18 libgdk-pixbuf-2.0-0 libgdk-pixbuf2.0-bin libgdk-pixbuf2.0-common libgif7 libgl1 libgl1-amber-dri libgl1-mesa-dri libglapi-mesa libglvnd0
  libglx-mesa0 libglx0 libgraphite2-3 libgtk2.0-0 libgtk2.0-bin libgtk2.0-common libharfbuzz0b libice-dev libice6 libjbig0 libjpeg-turbo8 libjpeg8 liblcms2-2 libllvm13
  libpango-1.0-0 libpangocairo-1.0-0 libpangoft2-1.0-0 libpciaccess0 libpcsclite1 libpixman-1-0 libpthread-stubs0-dev librsvg2-2 librsvg2-common libsm-dev libsm6
  libthai-data libthai0 libtiff5 libvulkan1 libwayland-client0 libwebp7 libx11-dev libx11-xcb1 libxau-dev libxaw7 libxcb-dri2-0 libxcb-dri3-0 libxcb-glx0
  libxcb-present0 libxcb-randr0 libxcb-render0 libxcb-shape0 libxcb-shm0 libxcb-sync1 libxcb-xfixes0 libxcb1-dev libxcomposite1 libxcursor1 libxdamage1 libxdmcp-dev
  libxfixes3 libxft2 libxi6 libxinerama1 libxkbfile1 libxmu6 libxpm4 libxrandr2 libxrender1 libxshmfence1 libxt-dev libxt6 libxtst6 libxv1 libxxf86dga1 libxxf86vm1
  mesa-vulkan-drivers openjdk-17-jdk-headless openjdk-17-jre openjdk-17-jre-headless session-migration ubuntu-mono x11-common x11-utils x11proto-dev xorg-sgml-doctools
  xtrans-dev
...
update-alternatives: using /usr/lib/jvm/java-17-openjdk-amd64/bin/jhsdb to provide /usr/bin/jhsdb (jhsdb) in auto mode
Setting up libgtk2.0-0:amd64 (2.24.33-2ubuntu2) ...
Setting up humanity-icon-theme (0.6.16) ...
Setting up libgail18:amd64 (2.24.33-2ubuntu2) ...
Setting up libgtk2.0-bin (2.24.33-2ubuntu2) ...
Setting up libgail-common:amd64 (2.24.33-2ubuntu2) ...
Setting up openjdk-17-jre:amd64 (17.0.3+7-0ubuntu0.22.04.1) ...
Setting up ubuntu-mono (20.10-0ubuntu2) ...
Setting up openjdk-17-jdk:amd64 (17.0.3+7-0ubuntu0.22.04.1) ...
update-alternatives: using /usr/lib/jvm/java-17-openjdk-amd64/bin/jconsole to provide /usr/bin/jconsole (jconsole) in auto mode
Processing triggers for ca-certificates (20211016) ...
Updating certificates in /etc/ssl/certs...
0 added, 0 removed; done.
Running hooks in /etc/ca-certificates/update.d...

done.
done.
Processing triggers for libglib2.0-0:amd64 (2.72.1-1) ...
Processing triggers for libc-bin (2.35-0ubuntu3) ...
Processing triggers for man-db (2.10.2-1) ...
Setting up at-spi2-core (2.44.0-3) ...
Processing triggers for libgdk-pixbuf-2.0-0:amd64 (2.42.8+dfsg-1) ...
Scanning processes...                                                                                                                                                     
Scanning candidates...                                                                                                                                                    
Scanning linux images...                                                                                                                                                  

Restarting services...
 /etc/needrestart/restart.d/systemd-manager
 systemctl restart packagekit.service postgresql@14-main.service ssh.service systemd-journald.service systemd-networkd.service systemd-resolved.service systemd-timesyncd.service systemd-udevd.service udisks2.service
Service restarts being deferred:
 systemctl restart systemd-logind.service
 systemctl restart user@1000.service

No containers need to be restarted.

No user sessions are running outdated binaries.

No VM guests are running outdated hypervisor (qemu) binaries on this host.

Next, you can test your fresh installation:

java -version

Output should be like this:

$ java -version
openjdk version "17.0.3" 2022-04-19
OpenJDK Runtime Environment (build 17.0.3+7-Ubuntu-0ubuntu0.22.04.1)
OpenJDK 64-Bit Server VM (build 17.0.3+7-Ubuntu-0ubuntu0.22.04.1, mixed mode, sharing)

A good practice is to set an environment variable JAVA_HOME with the path of the JDK installation.

export JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64/ echo $JAVA_HOME

Output should be like this:

$ export JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64/
$ echo $JAVA_HOME
/usr/lib/jvm/java-17-openjdk-amd64/
$ 

 

Manage two or more JDK installations

Imagine you have to use the last GA version for a specific project. First you install the latest GA version of OpenJDK:

sudo apt-get -y install openjdk-18-jdk

Output should be like this:

$ sudo apt-get -y install openjdk-18-jdk
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following additional packages will be installed:
  openjdk-18-jdk-headless openjdk-18-jre openjdk-18-jre-headless
Suggested packages:
  openjdk-18-demo openjdk-18-source visualvm libnss-mdns fonts-ipafont-gothic fonts-ipafont-mincho fonts-wqy-microhei | fonts-wqy-zenhei fonts-indic
The following NEW packages will be installed:
  openjdk-18-jdk openjdk-18-jdk-headless openjdk-18-jre openjdk-18-jre-headless
0 upgraded, 4 newly installed, 0 to remove and 12 not upgraded.
Need to get 268 MB of archives.
After this operation, 421 MB of additional disk space will be used.
Get:1 http://nova.clouds.archive.ubuntu.com/ubuntu jammy/universe amd64 openjdk-18-jre-headless amd64 18~36ea-1 [48.0 MB]
Get:2 http://nova.clouds.archive.ubuntu.com/ubuntu jammy/universe amd64 openjdk-18-jre amd64 18~36ea-1 [180 kB]
Get:3 http://nova.clouds.archive.ubuntu.com/ubuntu jammy/universe amd64 openjdk-18-jdk-headless amd64 18~36ea-1 [220 MB]
Get:4 http://nova.clouds.archive.ubuntu.com/ubuntu jammy/universe amd64 openjdk-18-jdk amd64 18~36ea-1 [10.9 kB]
Fetched 268 MB in 5s (58.3 MB/s)           
..
update-alternatives: using /usr/lib/jvm/java-18-openjdk-amd64/bin/jhsdb to provide /usr/bin/jhsdb (jhsdb) in auto mode
Setting up openjdk-18-jdk:amd64 (18~36ea-1) ...
update-alternatives: using /usr/lib/jvm/java-18-openjdk-amd64/bin/jconsole to provide /usr/bin/jconsole (jconsole) in auto mode
Processing triggers for hicolor-icon-theme (0.17-2) ...
Scanning processes...                                                                                                                                                     
Scanning candidates...                                                                                                                                                    
Scanning linux images...                                                                                                                                                  

Restarting services...
Service restarts being deferred:
 systemctl restart systemd-logind.service
 systemctl restart user@1000.service

No containers need to be restarted.

No user sessions are running outdated binaries.

No VM guests are running outdated hypervisor (qemu) binaries on this host.

Then, test your new installation:

java -version

Output should be like this:

$ java -version
openjdk version "18-ea" 2022-03-22
OpenJDK Runtime Environment (build 18-ea+36-Ubuntu-1)
OpenJDK 64-Bit Server VM (build 18-ea+36-Ubuntu-1, mixed mode, sharing)

Then set the JAVA_HOME environment variable:

export JAVA_HOME=/usr/lib/jvm/java-18-openjdk-amd64/ echo $JAVA_HOME

Output should be like this:

$ export JAVA_HOME=/usr/lib/jvm/java-18-openjdk-amd64/
$ echo $JAVA_HOME
/usr/lib/jvm/java-18-openjdk-amd64/
$ 

It’s not very convenient if you want to switch again to the version 17. Fortunately a tool exist: update-alternatives.

sudo update-alternatives --config java

Output should be like this:

$ sudo update-alternatives --config java
There are 2 choices for the alternative java (providing /usr/bin/java).

  Selection    Path                                         Priority   Status
------------------------------------------------------------
* 0            /usr/lib/jvm/java-18-openjdk-amd64/bin/java   1811      auto mode
  1            /usr/lib/jvm/java-17-openjdk-amd64/bin/java   1711      manual mode
  2            /usr/lib/jvm/java-18-openjdk-amd64/bin/java   1811      manual mode

Press  to keep the current choice[*], or type selection number: 1
update-alternatives: using /usr/lib/jvm/java-17-openjdk-amd64/bin/java to provide /usr/bin/java (java) in manual mode

Then, verify that the new java version is the choosen one:

java -version

Output should be like this:

$ java -version
openjdk version "17.0.3" 2022-04-19
OpenJDK Runtime Environment (build 17.0.3+7-Ubuntu-0ubuntu0.22.04.1)
OpenJDK 64-Bit Server VM (build 17.0.3+7-Ubuntu-0ubuntu0.22.04.1, mixed mode, sharing)

⚠️ Warning:⚠️ if you have set the JAVA_HOME environment variable you have to update it with the rigth path.

 

Test the JDK installation

To test your Java installation, you can write an Hello World application. Create a HelloWorld.java file and past the following code:

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

Save and compile it, then, run it:

javac HelloWorld.java java HelloWorld

Output should be like this:

$ javac HelloWorld.java 
$ java HelloWorld.java 
👋 Hello World!

That’s it, you have successfully installed and configured an OpenJDK on Ubuntu 22.04.

 

Go further

Check the offers of public cloud instance on OVHcloud.