Installing Java on macOS: A Comprehensive Guide

Java is a widely used programming language for building robust and secure applications. Its Write Once, Run Anywhere (WORA) capability has made it one of the most popular programming languages around. Whether you're a developer planning to code in Java or a user intending to run Java-based applications, you must have Java installed on your system. In this blog post, we will guide you through installing Java on a macOS system.

Prerequisites

link to this section

Before we start, ensure you have a system running macOS. You should also have administrative access to this system for software installation.

Step 1: Check for Existing Java Installation

link to this section

Before installing Java, it's useful to check whether it is already installed on your system. Open Terminal (you can find it in Applications -> Utilities, or just search for it using Spotlight) and type the following command: 

java -version

If Java is installed, this command will display the installed version. If Java is not installed, Terminal will prompt you to install it.

Step 2: Download Java

link to this section

If Java is not installed on your system, or if you want to install a different version, you can download it directly from the Oracle website.

  1. Visit the Oracle website at www.oracle.com/java/technologies/javase-jdk11-downloads.html .
  2. Choose the appropriate macOS installer for the Java version you need. As of writing, the latest stable release is Java SE 11 LTS.
  3. Accept the license agreement, then click the download link for "macOS Installer" to start the download.

Step 3: Install Java

link to this section

Once the installer is downloaded, follow these steps:

  1. Navigate to your Downloads folder and find the Java .dmg file.
  2. Double click on the file to start the installer.
  3. In the installer window, double click on the package icon to start the installation process.
  4. Follow the on-screen instructions. When prompted, enter your administrator password to allow the installation.

Step 4: Verify the Java Installation

link to this section

After the installation is complete, you can verify it by checking the Java version again in Terminal: 

java -version

You should now see the version of Java you installed.

Step 5: Set the JAVA_HOME Environment Variable

link to this section

Many Java-based applications use the JAVA_HOME environment variable to determine the Java installation to use. To set this variable, you need to find out where Java is installed. You can do this by running the command: 

/usr/libexec/java_home

This will output the path to the Java installation. To set the JAVA_HOME environment variable, add the following line to your .bash_profile or .zshrc file (depending on your shell), replacing /path/to/java with the path output by the above command: 

export JAVA_HOME=/path/to/java

Save the file and close it. The changes will take effect the next time you open a Terminal session, or you can source the file immediately with the following command: 

source ~/.bash_profile

or 

source ~/.zshrc

Conclusion

link to this section

Congratulations! You have successfully installed Java on your macOS system. Whether you're going to use it for development, or just need it to run certain applications, having Java installed is useful for many tasks. Happy coding!