How to Install Java in Ubuntu

1. Method 1: Installing Java via the Ubuntu Package Manager
2. Method 2: Installing Oracle JDK Manually
3. Method 3: Setting Up Environment Variables
4. Conclusion
5. FAQ

Installing Java in Ubuntu is a straightforward process that can empower you to develop and run Java applications seamlessly. Whether you’re a beginner or an experienced developer, having Java set up on your system is essential for various projects, including web applications, mobile apps, and server-side applications.

In this article, we’ll walk you through the steps to install Java on Ubuntu, ensuring you have everything you need to get started. With clear instructions and helpful tips, you’ll be able to install Java in no time. Let’s dive in!

Method 1: Installing Java via the Ubuntu Package Manager

One of the simplest ways to install Java in Ubuntu is by using the default package manager, apt. This method allows you to install either the OpenJDK or Oracle JDK, with OpenJDK being the open-source implementation of the Java Platform.

To start, open your terminal and update your package index:

sudo apt update

Next, you can install OpenJDK by executing the following command:

sudo apt install default-jdk

This command will install the default Java Development Kit (JDK) available in the Ubuntu repositories.

After the installation, you can verify if Java was installed successfully by checking the version:

java -version

Output:

openjdk version "11.0.11" 2021-04-20
OpenJDK Runtime Environment (build 11.0.11+9-Ubuntu-0ubuntu2)
OpenJDK 64-Bit Server VM (build 11.0.11+9-Ubuntu-0ubuntu2, mixed mode, sharing)

This command should display the version of Java installed on your system. If you see the version information, congratulations! You’ve successfully installed Java on your Ubuntu machine.

Using the package manager is a great way to install Java because it handles dependencies for you, ensuring that all necessary components are installed alongside the JDK. This method is particularly useful for beginners who may not want to deal with manual installations.

Method 2: Installing Oracle JDK Manually

If you prefer to use Oracle’s JDK, which might be necessary for specific applications or development environments, you can install it manually. This method requires a few more steps but is still manageable.

First, navigate to the Oracle JDK download page and find the latest version of the JDK. Once you’ve located the appropriate version, you can download it using wget. Replace the URL in the command below with the one you copied from the Oracle website:

wget https://download.oracle.com/java/17/latest/jdk-17_linux-x64_bin.deb

Next, install the downloaded package using dpkg:

sudo dpkg -i jdk-17_linux-x64_bin.deb

If you encounter any dependency issues, you can resolve them with:

sudo apt install -f

Now, let’s check if Oracle JDK is installed correctly:

java -version

Output:

java version "17.0.1" 2021-10-19
Java(TM) SE Runtime Environment (build 17.0.1+12)
Java HotSpot(TM) 64-Bit Server VM (build 17.0.1+12, mixed mode, sharing)

After executing the version command, you should see the Oracle JDK version. This installation process gives you the latest features and improvements directly from Oracle, making it ideal for those who need specific capabilities that may not be available in OpenJDK.

Method 3: Setting Up Environment Variables

After installing Java, it’s often necessary to set up environment variables to ensure that Java applications can locate the JDK. This step is crucial for development purposes.

Open your terminal and edit the .bashrc file:

nano ~/.bashrc

At the end of the file, add the following lines, adjusting the path to where your JDK is installed:

export JAVA_HOME=/usr/lib/jvm/java-17-oracle
export PATH=$PATH:$JAVA_HOME/bin

Once you’ve made these changes, save the file and exit. To apply the changes, run:

source ~/.bashrc

To confirm that the environment variables are set correctly, you can echo the JAVA_HOME variable:

echo $JAVA_HOME

Output:

/usr/lib/jvm/java-17-oracle

Setting the environment variables allows your system to recognize where Java is installed, which is especially important for running Java applications and tools that rely on the JDK. This step ensures a smooth development experience, as many IDEs and build tools will reference these variables when compiling and running Java applications.

Conclusion

Installing Java in Ubuntu is a straightforward process, whether you choose to use the package manager for OpenJDK or manually install Oracle JDK. Each method has its advantages, catering to different needs and preferences. Setting up environment variables is an essential step that enhances your development experience. With Java installed, you’re now ready to embark on your programming journey. Enjoy coding!

FAQ

1. How do I check if Java is installed on my Ubuntu system?
   You can check if Java is installed by running the command java -version in your terminal. If Java is installed, it will display the version information.

2. Can I install multiple versions of Java on Ubuntu?
   Yes, you can install multiple versions of Java on Ubuntu. You can manage them using the update-alternatives command to switch between versions as needed.

3. What is the difference between OpenJDK and Oracle JDK?
   OpenJDK is the open-source implementation of the Java Platform, while Oracle JDK includes additional commercial features and support from Oracle.

4. How do I uninstall Java from Ubuntu?
   To uninstall Java installed via the package manager, use the command sudo apt remove default-jdk or sudo apt remove oracle-java17-installer, depending on the version you installed.

5. Is it necessary to set JAVA_HOME?
   While not strictly necessary, setting the JAVA_HOME environment variable is recommended as it helps various applications and tools locate your Java installation.