I have created new Gradle project, added
apply plugin: \'antlr\'
and
dependencies { antlr \"org.antlr:antlr4:4.5.3\"
A sample is included in the Gradle "all" distribution under the "samples" folder. You can also simply browse the sample on GitHub.
https://github.com/gradle/gradle/tree/master/subprojects/docs/src/samples/antlr