Installing Java OpenJDK on macOS Catalina Posted on September 28, 2018 by Paul. Updated 15 October 2019. This is a short note about getting started with Java 11 LTS or Java 13 on macOS Catalina. As you probably know, starting with Java 11 there was a big change in the license under which the official Oracle JDK is provided. Oracle has revamped it's Java model and now sells the software. They now have an ' OpenJDK ' free version for end users. If you have an app that tries to use Java, it may be poorly written such that it will only attempt to use Apple's Java 6 which will not run on Catalina.

Since OS X 10.7 Java is not (pre-)installed anymore, let’s fix that. As I’m writing this, Java 11.0.4 is the latest version and AdoptOpenJDK is one of the best places to find Prebuilt OpenJDK Binaries. Easy to follow details about how to install OpenJDK are available here.

However, the easiest way is to select OpenJDK 11 (LTS), the HotSpot JVM, and macOS x64, which will expose two option like these:
Clicking on “Install JDK installer”, will download the OpenJDK installer package, e.g. OpenJDK11U-jdk_x64_mac_hotspot_11.0.4_11.pkg, which when executed, will install into this location: /Library/Java/JavaVirtualMachines/adoptopenjdk-11.jdk

Almost done. After opening a terminal, the successful installation of the JDK can be confirmed like so:

… hopefully showing something like this:

Java 6 Mac Os Catalina Free

JAVA_HOME 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:

In previous macOS versions, this was done in ~/.bash_profile. Now it’s done.

Source Code

The source code of the Java Platform, Standard Edition 11 Reference Implementations binaries is available under the GPLv2 in a single zip file.

API Specification

How To Install Java On Macos Catalina

The API Specification of the Java Platform, Standard Edition and Java Development Kit
can be found here: https://docs.oracle.com/en/java/javase/11/docs/api/
.

I bought a new Macbook recently which run Catalina (OS X 10.15) which is basically no different to OS X 10.11 or 10.10 – the only difference is that it slows your computer down if you are on an older model. Since Steve Jobs died innovation at Apple basically stopped; all the new devices is just the same as before but maybe with an extra camera or a bit more RAM or a faster CPU. The laptop that I bought is no exception compared to the Macbook Air that I bought 8 years ago.

I use Adobe Photoshop CS6 which requires Java 6 SE; it’s supposed to be an older version of JAVA but it actually does the job; but the JAVA downgrade that Apple offers doesn’t work for Catalina (10.15) – https://support.apple.com/kb/DL1572?viewlocale=en_US&locale=en_US; it should but they just deliberately made it so it doesn’t.

I found a great post online on how to fix this:-
https://www.harrisgeospatial.com/Support/Self-Help-Tools/Help-Articles/Help-Articles-Detail/ArtMID/10220/ArticleID/23780/Mac-OS-Catalina-1015-ENVIIDL-and-Legacy-Java-6-Dependencies – It really works and I was surprised.

How To Install Java 8 On Mac Catalina

The error message that you will receive is “A Newer Version of this package is already installed” but it’s not.

Java 6 Mac Os Catalina Update

I followed the instructions on the Harris Geo Spatial website and managed to generate a package that I was able to use to install JAVA6 SE; to save people hassle I have uploaded here and you can download it directly to save yourself from following the steps yourself. You download:-ModifiedJava6Install.pkg

I also download JAVA 7 too which can be downloaded here – it needs X86_64 architecture:-
jdk-7u80-macosx-x64.dmg