Masuk ke directory /tmp

$ cd /tmp

Download jdk21

$ wget https://download.oracle.com/java/21/latest/jdk-21_linux-x64_bin.deb

Install package jdk20

$ sudo apt-get -qqy install ./jdk-21_linux-x64_bin.deb

 Kemudian setting environment variable,

$ sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk-21.0.4-oracle-x64/bin/java 1919

$ sudo nano /etc/environment

Tambahkan baris :

JAVA_HOME="/usr/lib/jvm/jdk-21.0.4-oracle-x64/bin/java"

Lihat hasil setting :

$ source /etc/environment

$ echo $JAVA_HOME