Early Access to JDK 9

Change effective on 18 October 2016

Heroku now provides early access to prerelease versions of JDK 9. To use JDK 9 with your Java, Scala, Clojure, Groovy, or JRuby application, create a system.properties file in the root directory of your repository with the following contents:

java.runtime.version=9

Then add the file to Git, and JDK 9 will be installed the next time you deploy. For a full list of supported versions, see the Dev Center documentation on JVM versions.

For more information on configuring your JDK, see the Dev Center documentation for Java. For more information on JDK 9, see the official OpenJDK documentation.