Compile Apache Cassandra from sources
Prerequisites
Java
$ cat /opt/java/load_jdk11.sh
#! /bin/bash
export JAVA_HOME=/opt/java/jdk-11
export PATH=${JAVA_HOME}/bin:${PATH}
$ java -version
java version "11" 2018-09-25
Java(TM) SE Runtime Environment 18.9 (build 11+28)
Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11+28, mixed mode)
Ant
A decently recent version would do it:
$ ant -version
Apache Ant(TM) version 1.10.5 compiled on July 10 2018
How to proceed from here
Download the code (will take some time)
$ git clone https://github.com/apache/cassandra.git
[....]
$ cd cassandra
Compile the code (will take some more)
$ ant -Duse.jdk11=true
[....]
BUILD SUCCESSFUL
If everything went well, you should be now able to run your nice Cassandra instance with Java 11:
$ ./bin/cassandra
[cassandra] [git] [java]