Scalingo buildpack for Java

This is the official Scalingo buildpack for apps that use Maven as their build tool.

It's primarily used to build Java applications, but it can also build applications written in other JVM languages.

If you're using a different JVM build tool, use the appropriate buildpack:

• Gradle buildpack for Gradle projects
• Scala buildpack for sbt projects
• Clojure buildpack for Leiningen projects

Table of Contents

• Supported Maven Versions
• Application Requirements
• Configuration
  • OpenJDK Version
  • Maven Version
  • Buildpack Configuration

Supported Maven Versions

This buildpack officially supports Maven 3.x. Maven 4.x support will be added after its release.

Application Requirements

Your app requires a pom.xml file, or one of the other POM formats supported by the Maven Polyglot plugin, in the root directory.

Configuration

OpenJDK Version

Specify an OpenJDK version by creating a system.properties file in the root of your project directory and setting the java.runtime.version property. See the Java Support article for available versions and configuration instructions.

Maven Version

Specify a Maven version by adding the Maven Wrapper to your project. When this buildpack detects the presence of a mvnw script and a .mvn directory, it will run the Maven Wrapper instead of the default mvn command.

Alternatively, you can set the maven.version property in system.properties, though using the Maven Wrapper is the recommended approach.

Buildpack Configuration

Configure the buildpack by setting environment variables:

Environment Variable	Description	Default
MAVEN_CUSTOM_GOALS	Maven goals to execute	clean dependency:list install
MAVEN_CUSTOM_OPTS	Maven command-line options	-DskipTests
MAVEN_JAVA_OPTS	JVM options for Maven execution	(none)
MAVEN_SETTINGS_PATH	Path to a custom settings.xml file	(none)
MAVEN_SETTINGS_URL	URL from which to download a custom settings.xml file	(none)
MAVEN_HEROKU_CI_GOAL	Maven goal for Heroku CI test runs	test