Installing Tomcat on macOS 11 Big Sur

The Servlet 4.0 specification is out and Tomcat 9.0.x does support it. Time to dive into Tomcat 9.

Prerequisite: Java

Since OS X 10.7 Java is not (pre-)installed anymore, let’s fix that by installing a Prebuilt OpenJDK Binary. Easy to follow details about how to install OpenJDK are available here. Anyway, after opening the Terminal app,

java --version

hopefully shows something like this:

openjdk 11.0.9 2020-10-20
OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.9+11)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 11.0.9+11, mixed mode)

Whatever you do, when opening Terminal and running ‘java –version’, you should see something like this, with a version of at least 1.8.x I.e. Tomcat 9.x requires Java 8 or later.

JAVA_HOME is an important environment variable, not just for Tomcat, 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:

export JAVA_HOME=$(/usr/libexec/java_home)

Installing Tomcat

Here are the easy to follow steps to get it up and running on your Mac

1. Download a binary distribution of the core module: apache-tomcat-9.0.40 from here. I picked the tar.gz in Binary Distributions Core section.
2. Opening/unarchiving the archive will create a new folder structure in your Downloads folder: (btw, this free Unarchiver app is perfect for all kinds of compressed files and superior to the built-in Archive Utility.app)
   ~/Downloads/apache-tomcat-9.0.40
3. Open the Terminal app to move the unarchived distribution to /usr/local like so:
   sudo mkdir -p /usr/local
sudo mv ~/Downloads/apache-tomcat-9.0.40 /usr/local
4. To make it easy to replace this release with future releases, we are going to create a symbolic link that we are going to use when referring to Tomcat (after removing the old link, you might have from installing a previous version):
   sudo rm -f /Library/Tomcat
sudo ln -s /usr/local/apache-tomcat-9.0.40 /Library/Tomcat
5. Change ownership of the /Library/Tomcat folder hierarchy:
   sudo chown -R <your_username> /Library/Tomcat
6. Make all scripts in Tomcat’s ./bin folder executable:
   sudo chmod +x /Library/Tomcat/bin/*.sh

Tomcat 9.x

Starting and stoping Tomcat works with executing the provided scripts, like so:
/Library/Tomcat/bin/startup.sh
/Library/Tomcat/bin/shutdown.sh

Finally, after your started Tomcat, open your Mac’s Web browser and take a look at the default page: http://localhost:8080