What Do I Need Java For On Mac

This topic includes the following sections:

So you just upgraded your Mac (probably to Yosemite) and now you are getting annoying browser errors that say “To view this web content you need to install the Java Runtime Environment.” More annoyingly, after clicking through to Oracle’s Java.com to “Download Java for Mac OS X” and installing it, you still get the error! This is my first MAC ever and I'm still trying to get the hang of navigating my way around. Anyway, I'm also new to Java and I've been practicing on my Windows PC before it permanently died. Now that I'm on this MAC, I installed my JDK and now I need to set the JAVAHOME environment variable. I have no idea what to do. Hello, World in Java on Mac OS X This documents instructs you on how to setup a Java programming environment for your Mac OS X computer and provides a step-by-step guide to creating, compiling, and executing a Java program. We assume you are running at least OS X 10.2.3. All of the software is freely available on the Web.

System Requirements for Installing the JDK on macOS

The following are the system requirements for installing the JDK on macOS:

Any Intel-based computer running macOS.
Administrator privileges.
You cannot install Java for a single user. Installing the JDK on macOS is performed on a systemwide basis for all users. Administrator privileges are required to install the JDK on macOS.

Determining the Default JDK Version on macOS

When starting a Java application through the command line, the system uses the default JDK.

There can be multiple JDKs installed on the macOS system.

You can determine which version of the JDK is the default by entering java -version in a Terminal window. If the installed version is 13 Interim 0, Update 0, and Patch 0, then you see a string that includes the text 13. For example:

To run a different version of Java, either specify the full path, or use the java_home tool. For example:

$ /usr/libexec/java_home -v 13 --exec javac -version

Installing the JDK on macOS

Download the JDK .dmg file, jdk-13.interim.update.patch_osx-x64_bin.dmg.
Before the file can be downloaded, you must accept the license agreement.
From either the browser Downloads window or from the file browser, double-click the .dmg file to start it.
A Finder window appears that contains an icon of an open box and the name of the .pkg file.
Double-click the JDK 13.pkg icon to start the installation application.
The installation application displays the Introduction window.
Click Continue.
Click Install.
A window appears that displays the message: Installer is trying to install new software. Enter your password to allow this.
Enter the Administrator user name and password and click Install Software.
The software is installed and a confirmation window is displayed.

After the software is installed, you can delete the .dmg file if you want to save disk space.

Uninstalling the JDK on macOS

You must have Administrator privileges.

Note:

Do not attempt to uninstall Java by removing the Java tools from /usr/bin. This directory is part of the system software and any changes will be reset by Apple the next time that you perform an update of the OS.

Go to /Library/Java/JavaVirtualMachines.
Remove the directory whose name matches the following format by executing the rm command as a root user or by using the sudo tool:
/Library/Java/JavaVirtualMachines/jdk-13.interim.update.patch.jdk
For example, to uninstall 13 Interim 0 Update 0 Patch 0:
$ rm -rf jdk-13.jdk

Installation FAQ on macOS Platform

This topic provides answers for the following frequently asked questions about installing JDK on macOS computers.

What Do I Need Java For On Mac Os

1. How do I find out which version of Java is the system default?

When you run a Java application from the command line, it uses the default JDK. If you do not develop Java applications, then you do not need to worry about this. See Determining the Default JDK Version on macOS.

2. How do I uninstall Java?

See Uninstalling the JDK on macOS.

3. After installing Java for macOS 2012-006, can I continue to use Apple's Java 6 alongside the macOS JDK for Java 13?

If you want to continue to develop with Java 6 using command-line, then you can modify the startup script for your favorite command environment. For bash, use this:

$ export JAVA_HOME=`/usr/libexec/java_home -v 13`

Some applications use /usr/bin/java to call Java. After installing Java for macOS 2012-006, /usr/bin/java will find the newest JDK installed, and will use that for all of the Java-related command-line tools in /usr/bin. You may need to modify those applications to find Java 6, or contact the developer for a newer version of the application.

4. What happened to the Java Preferences app in Application Utilities?

The Java Preferences app was part of the Apple Java installation and is not used by Oracle Java. Therefore, macOS releases from Apple that do not include Apple Java will not include Java Preferences.