Change effective on 24 September 2014
Heroku’s Scala support now provides two new Java Virtual Machine runtimes. The upgraded versions are 1.7.0_55 and 1.8.0_20, while 1.6.0_27 remains the default. To use these runtimes, create a
system.properties file in your Scala project with the following contents:
1.8 for the JDK8. The new runtime will be installed during your next deployment.
See the Dev Center for more information on Heroku’s Scala support.