Java.md

Java

Installation Steps

Update the System

Before installing Java, make sure your system is up to date with the latest package versions.

sudo apt update
sudo apt upgrade -y

Download Oracle JDK

Go to the Oracle Java SE website to download the desired version.

Note

If you have a Raspberry Pi, download the ARM 64-bit version of Java.

Tip

You can also use wget to download the file directly from the terminal. Example:

wget https://download.oracle.com/java/XX/latest/jdk-XX_linux-aarch64_bin.tar.gz

Extract the Downloaded File

Extract the downloaded archive into a temporary directory.

tar -xvzf jdk-XX_linux-aarch64_bin.tar.gz

Configuration

Move the contents of the extracted folder to /usr/local/ for centralized management of binaries and libraries.

sudo mv jdk-XX /usr/local/

Next, create a symbolic link for the java binary in /usr/local/bin so that it is easily accessible from any terminal without specifying the full path.

sudo ln -s /usr/local/jdk-XX/bin/java /usr/local/bin/java

Note

This command makes the java binary globally available as a command. You can now use it directly.

Environment Variables

Although the symbolic link makes Java accessible, it's often useful to define the JAVA_HOME variable.

export JAVA_HOME=/usr/local/jdk-21
export PATH=$JAVA_HOME/bin:$PATH

Then, reload the configuration file with:

source ~/.bashrc

Verify the Installation

To verify that Java is correctly installed and that version 21 is used by default, run the following command:

java -version

Note

This should display something similar to:

java version "XX"
Java(TM) SE Runtime Environment (build XX+XX-XXXX)
Java HotSpot(TM) 64-Bit Server VM (build XX+XX-XXXX, mixed mode)