Issue
Your application needs a particular Java version but it isn't a Java or JVM app.
Resolution
Applications in languages other than Java can install a particular JVM using the heroku-jvm-common buildpack.
Add this buildpack to the start of the buildpacks list in your app:
$ heroku buildpacks:add -i 1 https://github.com/heroku/heroku-buildpack-jvm-common.git
This is a utility buildpack that only installs Java, so it doesn't require the app to be written in Java. But it does require a system.properties
file in the app to specify the Java version to install.
Add a file to your project called system.properties
, you can add the version of Java you need. Consult the Dev Center article here for the exact format of the file and the Java versions supported.