jnlp_server.rb

require 'rubygems'

gem 'rack', '>= 1.1.0'
gem 'jnlp', '>= 0.6.2'

require 'rack'
require 'jnlp'

require 'fileutils'
require 'open-uri'

server = 'http://localhost:4321'
jnlp_cache = 'jnlp'

maven_jnlps_url = "http://jnlp.concord.org/dev/org/concord/maven-jnlp"
families = %w{all-otrunk-snapshot sensor-applets}

jnlps = []
new_hrefs = []

puts "\nLoading most recent versioned jnlps from:\n"

families.each do |family|
  snapshot_version_path = "#{family}-CURRENT_VERSION.txt"
  snapshot_version = open("#{maven_jnlps_url}/#{family}/#{snapshot_version_path}").read
  versioned_jnlp_url = "#{maven_jnlps_url}/#{family}/#{family}-#{snapshot_version}.jnlp"
  puts "  #{versioned_jnlp_url} ..."
  jnlp = Jnlp::Jnlp.new(versioned_jnlp_url, jnlp_cache, {:include_pack_gz => true, :verbose => true})
  new_href = "#{server}#{jnlp.path}"
  jnlp.write_jnlp( { :dir => jnlp_cache, :jnlp => { :codebase => server, :href => new_href }, :snapshot => true } )
  new_hrefs << new_href
  jnlps << jnlp
end

puts "\nServing jnlps locally at:\n  #{new_hrefs.join("\n  ")}"

module Rack

  class Jnlp
    def initialize app
      @app = app
    end
    def call env      
      path = env["PATH_INFO"]
      # version-id=0.1.0-20090724.190215-918
      jar_version = env["QUERY_STRING"][/version-id=(.*)/, 1]
      versioned_jar_request = false
      if path[/\.jar$/] && jar_version
        versioned_jar_request = true
        # http://jnlp.concord.org/dev/org/concord/otrunk/otrunk.jar
        versioned_jar_path = path.gsub(/(.*?)(\.jar$)/, "\\1__V#{jar_version}\\2")
        # http://jnlp.concord.org/dev/org/concord/otrunk/otrunk__V0.1.0-20090724.190215-918.jar        
        env["PATH_INFO"] = versioned_jar_path
      end
      status, headers, body = @app.call env
      if versioned_jar_request
        headers['x-java-jnlp-version-id'] =	jar_version
        headers['Content-Type'] = 'application/java-archive'
      end
      [status, headers, body]
    end
  end

end

jnlp_app = Rack::Builder.new do
  map "/" do
    use Rack::Jnlp
    run Rack::Directory.new(jnlp_cache)
  end
end

puts "\nStarting server (press ctrl-C to quit)\n\n"
Rack::Handler::WEBrick.run(jnlp_app, :Port => 4321)