I tried to build a Docker Image using the following procedure described in the README, but it failed.
I used arm OS.

git clone https://github.com/antlr/antlr4.git
cd antlr4/docker
docker build -t antlr/antlr4 .

https://github.com/antlr/antlr4/blob/master/docker/README.md

The jdk image used in the Dockerfile does not support arm, so it may be necessary to specify the platform.
https://hub.docker.com/r/adoptopenjdk/openjdk11/tags

- docker build -t antlr/antlr4 .
+ docker build -t antlr/antlr4 --platform linux/amd64 .

It would be better to fix the README.