JRubyDaemon.java

public class JRubyDaemon implements Daemon {

  private Ruby runtime;
  private Thread thread;
  private RubyModule appModule;
  private boolean debug;
  private RubyModule daemon;

  public void init(DaemonContext arguments) throws Exception {

    debug = "true".equals(System.getProperty("JRubyDaemon.debug"));

    // mimicking startup from org.jruby.Main
    RubyInstanceConfig rubyConfig = new RubyInstanceConfig();
    rubyConfig.processArguments(arguments.getArguments());
    runtime = Ruby.newInstance(rubyConfig);
    Thread.currentThread().setContextClassLoader(runtime.getJRubyClassLoader());

    if (debug) log("Initialising JRuby program from: " + rubyConfig.getScriptFileName());

    // boot her up.  The script should yield control back to us (--daemon flag) so we
    // can give it back once in start once we are happy that everything is going to
    // work.  FYI, it also lets us bind to ports < 1024
    runtime.runFromMain(rubyConfig.getScriptSource(), rubyConfig.getScriptFileName());

    // check it has come up OK
    appModule = runtime.getModule("AppModule");
    if (appModule == null) { throw new RuntimeException("Couldn't get AppModule module from JRuby runtime"); }
    daemon = (RubyModule) appModule.getConstantAt("Daemon");
    if (daemon == null) { throw new RuntimeException("Couldn't get AppModule::Daemon module from JRuby runtime"); }

    Boolean wasSetup =
      (Boolean) JavaEmbedUtils.rubyToJava(runtime, daemon.callMethod("setup?"), Boolean.class);

    if (!wasSetup) {
      throw new RuntimeException("Script did not call AppModule::Daemon.setup");
    }

  private void log(String msg) {
    System.err.println("JRubyDaemon: " + msg);
  }

  public void start() throws Exception {
    thread = new Thread("Main") {
      @Override
      public void run() {
        if (debug) log("thread " + thread + " starting daemon...");
        daemon.callMethod("start");
      }
    };
    thread.setDaemon(false);
    thread.setContextClassLoader(runtime.getJRubyClassLoader());
    thread.start();
  }

  public void stop() throws Exception {
    // TODO Auto-generated method stub
    if (debug) log("Stopping...");
    try {
      daemon.callMethod("stop");
    } catch (MainExitException e) {}
    if (debug) log("Stopped");
  }

  public void destroy() {
    runtime.tearDown();
  }



}