HttpServerStartingMethod.java

private final void startHttpServers(@Observes @Initialized(ApplicationScoped.class) @Priority(LIBRARY_AFTER) final Object event, final BeanManager beanManager) throws IOException, InterruptedException {
  if (beanManager != null) {
    final Instance<Object> beans = beanManager.createInstance();
    assert beans != null;
    final Instance<HttpServer> httpServers = beans.select(HttpServer.class);
    assert httpServers != null;
    if (!httpServers.isUnsatisfied()) {
      synchronized (this.startedHttpServers) {
        for (final HttpServer httpServer : httpServers) {
          if (httpServer != null) {
            // This asynchronous method starts a daemon thread in
            // the background; see
            // https://github.com/GrizzlyNIO/grizzly-mirror/blob/2.3.x/modules/http-server/src/main/java/org/glassfish/grizzly/http/server/HttpServer.java#L816
            // and work backwards to the start() method.  Among
            // other things, that won't prevent the JVM from exiting
            // normally.  Think about that for a while.  We'll need
            // another mechanism to block the CDI container from
            // simply shutting down.
            httpServer.start();

            // We store our own list of started HttpServers to use
            // in other methods in this class rather than relying on
            // Instance<HttpServer> because we don't know what scope
            // the HttpServer instances in question are.  For
            // example, they might be in Dependent scope, which
            // would mean every Instance#get() invocation might
            // create a new one.
            this.startedHttpServers.add(httpServer);
          }
        }
        if (!this.startedHttpServers.isEmpty()) {
          // Here we fire an *asynchronous* event that will cause
          // the thread it is received on to block.  This is key:
          // the JVM will be prevented from exiting, and the thread
          // that the event is received on is (a) a non-daemon
          // thread and (b) managed by the container.  This is, in
          // other words, a clever way to take advantage of the CDI
          // container's mandated thread management behavior so
          // that the CDI container stays up for at least as long
          // as the HttpServer we spawned above.
          //
          // TODO: fire the event
          //
        }
      }
    }
  }
}