FunctionalJava uses the Retro Lambda project to backport Java 8 lambdas to Java 6 bytecode. This requires access to both JDK 6 and 8. The build system requires the environment variables
JAVA8_HOME to refer to the appropriate directories.
Building is done using Gradle. In the root directory run:
This will download the Gradle build tool and necessary dependencies and build FunctionalJava.