Change effective on 17 October 2018
Heroku’s support for Java, Scala, Clojure, and Gradle now includes support for OpenJDK versions 8u191 and 8u182. To use either of these JDK versions, create a
system.properties file in your application with contents like this:
After your next deployment, Heroku will install and run your app with the specified JDK. For more information, see the article on Heroku Support for Java in the Dev Center. For more information on JDK 8, see the official OpenJDK documentation.