Install Java on Ubuntu 22.04: A Step-by-Step Guide (OpenJDK & Oracle)

Need Java for your applications on Ubuntu 22.04? This guide walks you through installing Java using apt, covering both OpenJDK and Oracle JDK. Learn how to set up your environment and manage different Java versions effortlessly.

Why Install Java on Ubuntu?

Java is essential for running a wide range of applications, from web servers like Tomcat and Jetty to powerful tools, including Jenkins and Cassandra. Whether you're a developer or simply need to run Java-based software, this tutorial provides the necessary steps to get you up and running with Java on Ubuntu 22.04.

Prerequisites

Before we begin, make sure you have:

• An Ubuntu 22.04 server with a non-root user with sudo privileges and a firewall.

Installing Java: Your Options

You have two main options for installing Java:

• OpenJDK: The open-source implementation of Java, pre-packaged with Ubuntu.
• Oracle JDK: The official version from Oracle.

Both are officially recognized and largely identical since Java 11. Your choice depends on your desired licensing and whether you need to install the JRE separately (OpenJDK offers this).

Option 1: Quick Install of Default JRE/JDK (OpenJDK)

Ubuntu 22.04 defaults to OpenJDK 11. Here's how to install it:

1. Update your package index:

   sudo apt update
   

2. Install the JRE:

   sudo apt install default-jre
   

   This lets you run almost all Java software.

3. Verify the installation:

   java -version
   

4. Install the JDK (if needed for development):

   sudo apt install default-jdk
   

   This includes the JRE.

5. Verify the JDK installation:

   javac -version
   

Option 2: Installing Oracle JDK 11 on Ubuntu

Installing Oracle JDK requires a few more steps due to licensing:

1. Create an Oracle Account: Go to the Oracle website and create an account.

2. Download Oracle JDK 11:

   • Visit the Archive Downloads page.
   • Find the version matching the installer script version (check the oracle-java11-installer page for the correct version).
   • Download the Linux x64 .tar.gz package. Accept the license agreement before downloading.

3. Transfer the File to Your Server: Use scp (or your preferred method) to upload the downloaded file to your server's home directory.

   scp Downloads/jdk-11.0.13_linux-x64_bin.tar.gz sammy@your_server_ip:~
   

4. Add the Third-Party Repository:

   • Import the signing key:

     sudo gpg --homedir /tmp --no-default-keyring --keyring /usr/share/keyrings/oracle-jdk11-installer.gpg --keyserver keyserver.ubuntu.com --recv-keys EA8CACC073C3DB2A
     

   • Add the repository to your package sources:

     echo "deb [arch=amd64 signed-by=/usr/share/keyrings/oracle-jdk11-installer.gpg] https://ppa.launchpadcontent.net/linuxuprising/java/ubuntu jammy main" | sudo tee /etc/apt/sources.list.d/oracle-jdk11-installer.list > /dev/null
     

   • Update your package list:

     sudo apt update
     

5. Prepare for Installation:

   • Create the required directory:

     sudo mkdir -p /var/cache/oracle-jdk11-installer-local/
     

   • Move the downloaded archive:

     sudo cp jdk-11.0.13_linux-x64_bin.tar.gz /var/cache/oracle-jdk11-installer-local/
     

6. Install Oracle JDK:

   sudo apt install oracle-java11-installer-local
   

   Accept the license agreement when prompted.

Managing Java Versions on Ubuntu

You can have multiple Java installations. Use update-alternatives to switch between them:

sudo update-alternatives --config java

Choose the number corresponding to the desired Java version.

You can do this for other Java commands like javac:

sudo update-alternatives --config javac

Setting the JAVA_HOME Environment Variable

1. Find the Java Installation Path: Use update-alternatives to list your Java installations and their paths.

   sudo update-alternatives --config java
   

2. Edit /etc/environment: Open the file with nano or your preferred editor:

   sudo nano /etc/environment
   

3. Add the JAVA_HOME Variable: Add the following line to the end, replacing the path with your Java installation path (without the bin/ part):

   JAVA_HOME="/usr/lib/jvm/java-11-openjdk-amd64"
   

   This sets the variable for all users.

4. Reload the File:

   source /etc/environment
   

5. Verify the Variable:

   echo $JAVA_HOME
   

Ready to Develop with Java?

You've successfully installed Java (JRE and JDK) on your Ubuntu 22.04 system! Now you can run Java applications, develop new ones, and explore the world of Java development. This includes running software like Tomcat, Jetty, or even tools like Jenkins.