java

@POST
	@Path("/authenticate")
	public boolean authenticate(@HeaderParam("Authorization") String atoken,
								@DefaultValue("application/json") @HeaderParam("Content-Type") String contentType,
								@DefaultValue("application/json") @HeaderParam("Accept") String accept,
								String account) throws IOException {



		final AtomicBoolean authenticated = new AtomicBoolean(false);
		final AtomicBoolean done = new AtomicBoolean(false);
		final AtomicReference uidRef = new AtomicReference<>();

		FileInputStream serviceAccount = null;
		try {
			serviceAccount = new FileInputStream(FIREBASE_SNIPPET_PATH);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}

		if (FirebaseApp.getApps().isEmpty()) {

			FirebaseOptions options = new FirebaseOptions.Builder()
					.setCredential(FirebaseCredentials.fromCertificate(serviceAccount))
					.setDatabaseUrl("https://dojo-ibl.firebaseio.com")
					.build();

			FirebaseApp.initializeApp(options, "dojo-ibl");
		}

		FirebaseApp app = FirebaseApp.getInstance("dojo-ibl");

		Task<FirebaseToken> task = FirebaseAuth.getInstance(app).verifyIdToken(atoken);

		while (!task.isComplete()) {
			try {
				Thread.sleep(50);
			} catch (InterruptedException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		if (task.isSuccessful()) {
			uidRef.set(task.getResult().getUid());
			authenticated.set(true);
			done.set(true);
		}
		else {
			task.getException().printStackTrace();
			authenticated.set(false);
			done.set(true);
		}

		return authenticated.get();
	}