Adding Oracle JDK17 LTS in Debian Alternatives system
Philosophical perspective
The Debian alternatives system creates a way for several programs that fulfill the same or similar functions to be listed as alternative implementations that are installed simultaneously but with one particular implementation designated as the default.
source: Debian alternatives
If you use Debian you should manage your multiple Java installation under this system.
List existing Java alternatives
In your Debian machine, you can query the existing configured Java alternatives with
stylee@matrix17:~$ sudo update-java-alternatives -l
java-1.11.0-openjdk-amd64 1111 /usr/lib/jvm/java-1.11.0-openjdk-amd64
jdk-11.0.12 1112 /usr/lib/jvm/jdk-11.0.12
oracle-java6-jdk-amd64 316 /usr/lib/jvm/oracle-java6-jdk-amd64
oracle-java8-jdk-amd64 318 /usr/lib/jvm/oracle-java8-jdk-amd64
stylee@matrix17:~$
I installed JDK 17 from Oracle’s deb package and I have
stylee@matrix17:~$ dpkg -l |grep jdk
ii jdk-17 17-ga amd64 Java Platform Standard Edition Development Kit
stylee@matrix17:~$
but it doesn’t appear in my alternatives configuration. Oracle does not support the configuration for Debian alternatives.
To enable it, we have to follow the follwing steps.
Create a jinfo file for JDK 17
Following previous Oracle JDK11 article, we can easily adapt it to our version (you can download it here).
name=jdk-17
priority=1700
section=main
hl java /usr/lib/jvm/jdk-17/bin/java
hl jexec /usr/lib/jvm/jdk-17/lib/jexec
hl keytool /usr/lib/jvm/jdk-17/bin/keytool
hl rmiregistry /usr/lib/jvm/jdk-17/bin/rmiregistry
jdk jar /usr/lib/jvm/jdk-17/bin/jar
jdk jarsigner /usr/lib/jvm/jdk-17/bin/jarsigner
jdk javac /usr/lib/jvm/jdk-17/bin/javac
jdk javadoc /usr/lib/jvm/jdk-17/bin/javadoc
jdk javap /usr/lib/jvm/jdk-17/bin/javap
jdk jcmd /usr/lib/jvm/jdk-17/bin/jcmd
jdk jconsole /usr/lib/jvm/jdk-17/bin/jconsole
jdk jdb /usr/lib/jvm/jdk-17/bin/jdb
jdk jdeps /usr/lib/jvm/jdk-17/bin/jdeps
jdk jfr /usr/lib/jvm/jdk-17/bin/jfr
jdk jhsdb /usr/lib/jvm/jdk-17/bin/jhsdb
jdk jimage /usr/lib/jvm/jdk-17/bin/jimage
jdk jinfo /usr/lib/jvm/jdk-17/bin/jinfo
jdk jlink /usr/lib/jvm/jdk-17/bin/jlink
jdk jmap /usr/lib/jvm/jdk-17/bin/jmap
jdk jmod /usr/lib/jvm/jdk-17/bin/jmod
jdk jpackage /usr/lib/jvm/jdk-17/bin/jpackage
jdk jps /usr/lib/jvm/jdk-17/bin/jps
jdk jrunscript /usr/lib/jvm/jdk-17/bin/jrunscript
jdk jshell /usr/lib/jvm/jdk-17/bin/jshell
jdk jstack /usr/lib/jvm/jdk-17/bin/jstack
jdk jstat /usr/lib/jvm/jdk-17/bin/jstat
jdk jstatd /usr/lib/jvm/jdk-17/bin/jstatd
jdk serialver /usr/lib/jvm/jdk-17/bin/serialver
Put it in the right position, under
/usr/lib/jvm/.jdk-17.jinfo
Right now, update-alternatives just detect it
stylee@matrix17:~$ sudo update-java-alternatives -l
java-1.11.0-openjdk-amd64 1111 /usr/lib/jvm/java-1.11.0-openjdk-amd64
jdk-11.0.12 1112 /usr/lib/jvm/jdk-11.0.12
jdk-17 1700 /usr/lib/jvm/jdk-17
oracle-java6-jdk-amd64 316 /usr/lib/jvm/oracle-java6-jdk-amd64
oracle-java8-jdk-amd64 318 /usr/lib/jvm/oracle-java8-jdk-amd64
stylee@matrix17:~$
But it’s not finished, yet: we have to tell update-alternatives which binary
to bind.
Configure JDK 17 binaries to alternatives system
Launch the following commands
sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk-17/bin/java 1700
sudo update-alternatives --install /usr/bin/jexec jexec /usr/lib/jvm/jdk-17/lib/jexec 1700
sudo update-alternatives --install /usr/bin/keytool keytool /usr/lib/jvm/jdk-17/bin/keytool 1700
sudo update-alternatives --install /usr/bin/rmiregistry rmiregistry /usr/lib/jvm/jdk-17/bin/rmiregistry 1700
sudo update-alternatives --install /usr/bin/jar jar /usr/lib/jvm/jdk-17/bin/jar 1700
sudo update-alternatives --install /usr/bin/jarsigner jarsigner /usr/lib/jvm/jdk-17/bin/jarsigner 1700
sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk-17/bin/javac 1700
sudo update-alternatives --install /usr/bin/javadoc javadoc /usr/lib/jvm/jdk-17/bin/javadoc 1700
sudo update-alternatives --install /usr/bin/javap javap /usr/lib/jvm/jdk-17/bin/javap 1700
sudo update-alternatives --install /usr/bin/jcmd jcmd /usr/lib/jvm/jdk-17/bin/jcmd 1700
sudo update-alternatives --install /usr/bin/jconsole jconsole /usr/lib/jvm/jdk-17/bin/jconsole 1700
sudo update-alternatives --install /usr/bin/jdb jdb /usr/lib/jvm/jdk-17/bin/jdb 1700
sudo update-alternatives --install /usr/bin/jdeps jdeps /usr/lib/jvm/jdk-17/bin/jdeps 1700
sudo update-alternatives --install /usr/bin/jfr jfr /usr/lib/jvm/jdk-17/bin/jfr 1700
sudo update-alternatives --install /usr/bin/jhsdb jhsdb /usr/lib/jvm/jdk-17/bin/jhsdb 1700
sudo update-alternatives --install /usr/bin/jimage jimage /usr/lib/jvm/jdk-17/bin/jimage 1700
sudo update-alternatives --install /usr/bin/jinfo jinfo /usr/lib/jvm/jdk-17/bin/jinfo 1700
sudo update-alternatives --install /usr/bin/jlink jlink /usr/lib/jvm/jdk-17/bin/jlink 1700
sudo update-alternatives --install /usr/bin/jmap jmap /usr/lib/jvm/jdk-17/bin/jmap 1700
sudo update-alternatives --install /usr/bin/jmod jmod /usr/lib/jvm/jdk-17/bin/jmod 1700
sudo update-alternatives --install /usr/bin/jpackage jpackage /usr/lib/jvm/jdk-17/bin/jpackage 1700
sudo update-alternatives --install /usr/bin/jps jps /usr/lib/jvm/jdk-17/bin/jps 1700
sudo update-alternatives --install /usr/bin/jrunscript jrunscript /usr/lib/jvm/jdk-17/bin/jrunscript 1700
sudo update-alternatives --install /usr/bin/jshell jshell /usr/lib/jvm/jdk-17/bin/jshell 1700
sudo update-alternatives --install /usr/bin/jstack jstack /usr/lib/jvm/jdk-17/bin/jstack 1700
sudo update-alternatives --install /usr/bin/jstat jstat /usr/lib/jvm/jdk-17/bin/jstat 1700
sudo update-alternatives --install /usr/bin/jstatd jstatd /usr/lib/jvm/jdk-17/bin/jstatd 1700
sudo update-alternatives --install /usr/bin/serialver serialver /usr/lib/jvm/jdk-17/bin/serialver 1700
and that’s all, it’s all configured correctly.
Use your JDK 17
To use it, run the following
stylee@matrix17:~$ sudo update-java-alternatives -s jdk-17
update-alternatives: errore: nessuna alternativa per iceweasel-javaplugin.so
update-alternatives: errore: nessuna alternativa per jaotc
update-alternatives: errore: nessuna alternativa per jdeprscan
update-alternatives: errore: nessuna alternativa per jmc
stylee@matrix17:~$
To prove your java executable is the right one
stylee@matrix17:~$ java -version
java version "17" 2021-09-14 LTS
Java(TM) SE Runtime Environment (build 17+35-LTS-2724)
Java HotSpot(TM) 64-Bit Server VM (build 17+35-LTS-2724, mixed mode, sharing)
stylee@matrix17:~$