Apache Buildr Task for Generating Java sources using the Java Annotation Processor

buildr_apt_task.rb

AWS_JAVA_SDK_BUILD_TOOLS = ["com.amazonaws:aws-java-sdk:jar:1.3.10",
                            "com.amazonaws:aws-java-sdk-flow-build-tools:jar:1.3.10"]

# The following is assumed to be embedded inside a project definition, otherwise 
# you will need to pass the project to the task.
...

# Task for Generating Sources via Java APT, note this overwrites any current source
task :apt do
  rm_rf project.path_to(:src, :generated, :java)
  mkdir_p project.path_to(:src, :generated, :java)
  classpath = Buildr.artifacts(AWS_JAVA_SDK_BUILD_TOOLS).each(&:invoke).map(&:to_s)
  classpath << project.path_to(:target, :classes)
  Buildr.ant("apt") do |ant|
    ant.apt :includeantruntime => false, 
            :fork => true,
            :optimize => "on",
            :srcdir => project.path_to(:src, :main, :java), # what files to use as input
            :classpath => classpath.join(File::PATH_SEPARATOR), # what's the classpath, the aws build tools jar needs to be here
            :source => "1.5", # APT only works with 1.5 or lower...
            :verbose => true do
              ant.compilerarg :line => "-proc:only" # don't compile, process only
              ant.compilerarg :line => "-s #{project.path_to(:src, :generated, :java)}" # where to put the generated source
            end
  end
end