How I got the latest clojure, java, leiningen versions on ubuntu

Installing the latest jdk in the ubuntu packages, with the clojure there, with leiningen also from apt, gave a warning every time I invoked leiningen. No good!

Following the clojure installation instructions, it helpfully overwrote itself. Cool! Clojure 1.11.1

'leiningen update' didn't want to self-update since it was installed by a package manager. :( so I uninstalled it from the package manager.

I also had 2 installed java versions, 11 and 17! But the latest is 20. Is it the greatest? idk let me use it and I'll find out...

So I uninstalled java and leiningen. Now clojure doesn't work, ok!

First to install java. I go here https://adoptium.net/

even though the website looks like angular material design I plow ahead... find the downloads page... linux x64 v20 please! download the tar.gz and unzip it.

Now my sysadmin skillz come in to play. Put it in /opt/java: /opt/java/jdk-20+36/

Now I need to set JAVA_HOME and put java on my path.

export JAVA_HOME=/opt/java/jdk-20+36/

in my ~/.profile ok!

Also link $JAVA_HOME/bin/java to /usr/local/bin and do the same for javac. All done, no warnings!

As for lein, its readme has a link to the lein script. So I got that and ran that and it figured itself out ~^_^~