Published 2023-09-28.
Time to read: 1 minutes.

This page is part of the posts collection, categorized under Java, Ubuntu.

The Java Development Kit (JDK) version 17 is compatible with v11 and v8. Installing the JDK also installs the JRE, as you can see from the highlighted dependency shown below:

Shell

$ apt show -a openjdk-17-jdk
Package: openjdk-17-jdk
  Version: 17.0.8.1+1~us1-0ubuntu1~23.04
  Priority: optional
  Section: java
  Source: openjdk-17
  Origin: Ubuntu
  Maintainer: Ubuntu Developers 
  Original-Maintainer: OpenJDK Team 
  Bugs: https://bugs.launchpad.net/ubuntu/+filebug
  Installed-Size: 1544 kB
  Provides: java-compiler, java-sdk (= 17), java10-sdk, java11-sdk, java12-sdk, java13-sdk, java14-sdk, java15-sdk, java16-sdk, java17-sdk, java2-sdk, java5-sdk, java6-sdk, java7-sdk, java8-sdk, java9-sdk
  Depends: openjdk-17-jre (= 17.0.8.1+1~us1-0ubuntu1~23.04), openjdk-17-jdk-headless (= 17.0.8.1+1~us1-0ubuntu1~23.04), libc6 (>= 2.34), zlib1g (>= 1:1.1.4)
  Recommends: libxt-dev
  Suggests: openjdk-17-demo, openjdk-17-source, visualvm
  Homepage: https://openjdk.java.net/
  Download-Size: 1486 kB
  APT-Sources: http://archive.ubuntu.com/ubuntu lunar-updates/main amd64 Packages
  Description: OpenJDK Development Kit (JDK)
    OpenJDK is a development environment for building applications,
    applets, and components using the Java programming language.

  Package: openjdk-17-jdk
  Version: 17.0.6+10-1ubuntu2
  Priority: optional
  Section: java
  Source: openjdk-17
  Origin: Ubuntu
  Maintainer: Ubuntu Developers 
  Original-Maintainer: OpenJDK Team 
  Bugs: https://bugs.launchpad.net/ubuntu/+filebug
  Installed-Size: 4732 kB
  Provides: java-compiler, java-sdk, java10-sdk, java11-sdk, java12-sdk, java13-sdk, java14-sdk, java15-sdk, java16-sdk, java17-sdk, java2-sdk, java5-sdk, java6-sdk, java7-sdk, java8-sdk, java9-sdk
  Depends: openjdk-17-jre (= 17.0.6+10-1ubuntu2), openjdk-17-jdk-headless (= 17.0.6+10-1ubuntu2), libc6 (>= 2.34)
  Recommends: libxt-dev
  Suggests: openjdk-17-demo, openjdk-17-source, visualvm
  Homepage: https://openjdk.java.net/
  Download-Size: 4585 kB
  APT-Sources: http://archive.ubuntu.com/ubuntu lunar/main amd64 Packages
  Description: OpenJDK Development Kit (JDK)
    OpenJDK is a development environment for building applications,
    applets, and components using the Java programming language. 

Install OpenJDK 17 and its dependencies:

Shell

$ yes | sudo apt install openjdk-17-jdk

Setting the Default Java Version

The man page for update-java-alternatives is:

Shell

$ man update-java-alternatives
UPDATE-JAVA-ALTERNATIVESystem Manager's MUPDATE-JAVA-ALTERNATIVES(8)

NAME
        update-java-alternatives  -  update  alternatives for jre/sdk
        installations

SYNOPSIS
        update-java-alternatives [--jre] [--plugin] [-v|--verbose]
              -l|--list [<jname>]
              -s|--set <jname>
              -a|--auto
              -h|-?|--help

DESCRIPTION
        update-java-alternatives updates all  alternatives  belonging
        to  one  runtime or development kit for the Java language.  A
        package does provide these information of  it's  alternatives
        in /usr/lib/jvm/.<jname>.jinfo.

OPTIONS
        -l|--list [<jname>]
              List  all installed packages (or just <jname>) provid‐
              ing information to set a bunch of  java  alternatives.
              Verbose  output shows each alternative provided by the
              packages.

        -a|--auto
              Switch all alternatives of registered jre/sdk  instal‐
              lations to automatic mode.

        -s|--set <jname>
              Set all alternatives of the registered jre/sdk instal‐
              lation to the program path provided by the <jname> in‐
              stallation.

        --jre  Limit  the actions to alternatives belong to a runtime
              environment, not a development kit.

        --jre-headless
              Limit the actions to alternatives belong to the  head‐
              less part of a runtime environment.

        --plugin
              Limit  the  actions  to alternatives providing browser
              plugins.

        -h|--help
              Display a help message.

        -v|--verbose
              Verbose output.

FILES
        /usr/lib/jvm/.*.jinfo
              A text file describing a  jre/sdk  installation.  Con‐
              sists  of some variables of the form <var>=<value> and
              a list of alternatives  of  the  form  jre|jdk  <name>
              <path>.

AUTHOR
        update-java-alternatives  and this manual page was written by
        Matthias Klose <doko@ubuntu.com>.

                              May 2006   UPDATE-JAVA-ALTERNATIVES(8) 

The above man page neglects to say that a package version’s priority is set from its version number. Thus a newer version would normally have a higher priority. To get a list of the installed Java versions, type:

Shell

$ sudo update-java-alternatives --list
java-1.11.0-openjdk-amd64      1111       /usr/lib/jvm/java-1.11.0-openjdk-amd64
java-1.17.0-openjdk-amd64      1711       /usr/lib/jvm/java-1.17.0-openjdk-amd64 

As you can see, my machine had Java 11 and 17 installed. To set the newest version to be the default, type:

Shell

$ sudo update-java-alternatives -a

$ java -version
openjdk version "17.0.8.1" 2023-08-24
OpenJDK Runtime Environment (build 17.0.8.1+1-Ubuntu-0ubuntu123.04)
OpenJDK 64-Bit Server VM (build 17.0.8.1+1-Ubuntu-0ubuntu123.04, mixed mode, sharing) 

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