Java is a runtime environment maintained by Oracle that you must install on your Mac to be able to run applications written using the Java programming language. Moreover, Java allows developers to make apps available on multiple operating systems at the same time because Java-based utilities.

See JDK 7 and JRE 7 Installation Guide for general information about installing JDK 7 and JRE 7.

See the Mac OS X Platform Install FAQ for general information about installing JDK 7 on Mac OS X.

System Requirements

Any Intel-based Mac running Mac OS X 10.7.3 (Lion) or later.
Administrator privileges.

Many Adobe applications depend on the Oracle Java Runtime Environment (JRE) for some features to work. Apple recently changed the way it includes Java in Mac OS, and with Lion, Java is no longer preinstalled. It is now an optional install that you must select. JAVAHOME is an important environment variable and it’s important to get it right. Here is a trick that allows me to keep the environment variable current, even after a Java Update was installed. In /.zshrc, I set the variable like so. 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. I tried following some of these guides and didn't get very far. Mkyong.com: How to set JAVAHOME variable in Mac OSX. YouTube: How to set environment variables on mac, linux, solaris, rhel.

Note that installing the JDK on a Mac is performed on a system wide basis, for all users, and administrator privileges are required. You cannot install Java for a single user.

Installing the JDK also installs the JRE. The one exception is that the system will not replace the current JRE with a lower version. To install a lower version of the JRE, first uninstall the current version.

JDK 7 Installation Instructions

Installation of the 64-bit JDK on Mac Platforms

When you download the Java Development Kit (JDK), the associated Java Runtime Environment (JRE) is installed at the same time. The JavaFX SDK and Runtime are also installed and integrated into the standard JDK directory structure.

Depending on your processor, the downloaded file has one of the following names:

jdk-7u<version>-macosx-amd64.dmg
jdk-7u<version>-macosx-x64.dmg

Where <version> is 6 or later.

1. Download the file. Before the file can be downloaded, you must accept the license agreement.

2. From either the Downloads window of the browser, or from the file browser, double click the .dmg file to launch it.

3. A Finder window appears containing an icon of an open box and the name of the .pkg file Double click the package icon to launch the Install app.

4. The Install app displays the Introduction window. Click Continue.

4a. Note that, in some cases, a Destination Select window appears. This is a bug, as there is only one option available. If you see this window, select Install for all users of this computer to enable the continue button. Click Continue.

5. The Installation Type window appears. Click Install.

6. A window appears which says 'Installer is trying to install new software. Type your password to allow this.' Enter the Administrator login and password and click Install Software.

7. The software is installed and a confirmation window appears. Click the ReadMe for more information about the installation.

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

Determining the Default Version of the JDK

A: If you have not yet installed Apple's Java Mac OS X 2012-006 update, then you are still using a version of Apple Java 6 that includes the plug-in and the Java Preferences app. See Note for Users of Macs that Include Apple Java 6 Plug-in.

There can be multiple JDKs installed on a system – as many as you wish.

When launching a Java application through the command line, the system uses the default JDK. It is possible for the version of the JRE to be different than the version of the JDK.

You can determine which version of the JDK is the default by typing java -version in a Terminal window. If the installed version is 7u6, you will see a string that includes the text 1.7.0_06. For example:

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

For more information, see the java_home(1) man page.

Uninstalling the JDK

To uninstall the JDK, you must have Administrator privileges and execute the remove command either as root or by using the sudo(8) tool.

Navigate to /Library/Java/JavaVirtualMachines and remove the directory whose name matches the following format:^*

For example, to uninstall 7u6:

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 you perform an update of the OS.

^*The 7u4 and 7u5 releases were installed into a directory that does not follow this format. To uninstall 7u4 or 7u5, remove the 1.7.0.jdk directory from the same location.

This DrJava-based Java programming environment is no longer being supported(because DrJava in no longer being actively developed and DrJava is incompatible with Java 11).It has been replaced by the following IntelliJ-based programming environment forMac OS X.

This document instructs you on how to set up our Java programming environment for your Mac OS X computer. It also provides a step-by-step guide for creating, compiling, and executing a Java program using either DrJava or the Terminal.All of the software used is freely available.

You will need an Intel-based Mac runningMac OS X 10.8 (Mountain Lion) to Mac OS X 10.13 (High Sierra).

You can defer steps 4–6 until Section 1.5 of the textbook.

0. Install the Programming Environment

Our installer downloads, installs, and configures the Java programming environment you will be using, including DrJava, and the standard libraries from our textbook.

Log in to the user account in which you will be programming.Your account must have Administrator privileges (with a non-blank password)and you must be connected to the Internet.
Install Oracle's implementation of the Java Platform, Standard Edition Development Kit (JDK 8).Do not install either JDK 9 or JDK 10, as they are currently incompatible with DrJava.
- Browse toJava SE Development Kit 8u171.In the first table, check Accept License Agreementand the click jdk-8u171-macosx-x64.dmg,which corresponds to the entry for Mac OS X.The exact verison 8u171 is not essential.
- Double click the downloaded file jdk-8u171-macosx-x64.dmg to begin the installation.Enter your OS X password when prompted.We recommend all of the default options.
- Delete jdk-8u171-macosx-x64.dmg.
To install,
- Download introcs.zip to the Desktop;double-click it to unzip (if necessary). This creates introcs.app. Security and Privacy -> General -> Allow applications downloaded from: Anywhere.
  To enable this option, you may need to click the lock in the lower left-hand corner(and type your password when prompted).-->
- Double-click introcs.app to perform the installation.If you receive a warning that introcs.app is an applicationdownloaded from the Internet, click Open.
- Enter your OS X password when prompted.
If the installation succeeds, you will see the following:
- A Terminal window containing approximately thisexecution log.
- A Standard Drawing window containing a red bullseye and a textbook gra

Contents

System Requirements

JDK 7 Installation Instructions

Installation of the 64-bit JDK on Mac Platforms

Determining the Default Version of the JDK

Uninstalling the JDK

Java Environment Download Mac