Java tutorial
/*** Copyright (c) 2015 CommonsWare, LLC Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0. Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. Covered in detail in the book _The Busy Coder's Guide to Android Development_ https://commonsware.com/Android */ package com.commonsware.android.webserver.websockets; import android.app.Notification; import android.app.PendingIntent; import android.app.Service; import android.content.Intent; import android.content.res.AssetFileDescriptor; import android.content.res.AssetManager; import android.os.IBinder; import android.support.v4.app.NotificationCompat; import android.util.Log; import com.koushikdutta.async.AsyncServer; import com.koushikdutta.async.callback.CompletedCallback; import com.koushikdutta.async.http.WebSocket; import com.koushikdutta.async.http.server.AsyncHttpServer; import com.koushikdutta.async.http.server.AsyncHttpServerRequest; import com.koushikdutta.async.http.server.AsyncHttpServerResponse; import com.koushikdutta.async.http.server.HttpServerRequestCallback; import java.io.IOException; import java.net.Inet4Address; import java.net.InetAddress; import java.net.NetworkInterface; import java.net.SocketException; import java.util.ArrayList; import java.util.Date; import java.util.Enumeration; import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit; import de.greenrobot.event.EventBus; public class WebServerService extends Service implements Runnable { private AsyncHttpServer server; final private ArrayList<WebSocket> sockets = new ArrayList<WebSocket>(); final private ScheduledExecutorService timer = Executors.newSingleThreadScheduledExecutor(); @Override public void onCreate() { super.onCreate(); server = new AsyncHttpServer(); server.websocket("/ss", new WebSocketClientCallback()); server.get("/.*", new AssetRequestCallback()); server.listen(4999); raiseStartedEvent(); foregroundify(); timer.scheduleAtFixedRate(this, 3000, 3000, TimeUnit.MILLISECONDS); } @Override public int onStartCommand(Intent i, int flags, int startId) { return (START_NOT_STICKY); } @Override public void onDestroy() { timer.shutdownNow(); EventBus.getDefault().removeAllStickyEvents(); EventBus.getDefault().postSticky(new ServerStoppedEvent()); server.stop(); AsyncServer.getDefault().stop(); // no, really, I mean stop super.onDestroy(); } @Override public IBinder onBind(Intent intent) { throw new UnsupportedOperationException("Go away"); } @Override public void run() { for (WebSocket socket : sockets) { socket.send(new Date().toString()); } } private void raiseStartedEvent() { ServerStartedEvent event = new ServerStartedEvent(); try { for (Enumeration<NetworkInterface> enInterfaces = NetworkInterface.getNetworkInterfaces(); enInterfaces .hasMoreElements();) { NetworkInterface ni = enInterfaces.nextElement(); for (Enumeration<InetAddress> enAddresses = ni.getInetAddresses(); enAddresses.hasMoreElements();) { InetAddress addr = enAddresses.nextElement(); if (addr instanceof Inet4Address) { event.addUrl("http://" + addr.getHostAddress() + ":4999"); } } } } catch (SocketException e) { Log.e(getClass().getSimpleName(), "Exception in IP addresses", e); } EventBus.getDefault().removeAllStickyEvents(); EventBus.getDefault().postSticky(event); } private void foregroundify() { NotificationCompat.Builder b = new NotificationCompat.Builder(this); Intent iActivity = new Intent(this, MainActivity.class); PendingIntent piActivity = PendingIntent.getActivity(this, 0, iActivity, 0); Intent iReceiver = new Intent(this, StopReceiver.class); PendingIntent piReceiver = PendingIntent.getBroadcast(this, 0, iReceiver, 0); b.setAutoCancel(true).setDefaults(Notification.DEFAULT_ALL).setContentTitle(getString(R.string.app_name)) .setContentIntent(piActivity).setSmallIcon(R.mipmap.ic_launcher) .setTicker(getString(R.string.app_name)) .addAction(R.drawable.ic_stop_white_24dp, getString(R.string.notify_stop), piReceiver); startForeground(1337, b.build()); } private class AssetRequestCallback implements HttpServerRequestCallback { private final AssetManager assets; AssetRequestCallback() { assets = getAssets(); } @Override public void onRequest(AsyncHttpServerRequest request, AsyncHttpServerResponse response) { String path = request.getPath(); try { if (path.length() == 0 || "/".equals(path)) { path = "index.html"; } else if (path.startsWith("/")) { path = path.substring(1); } AssetFileDescriptor afd = getAssets().openFd(path); response.sendStream(afd.createInputStream(), afd.getLength()); } catch (IOException e) { handle404(response, path, e); } } private void handle404(AsyncHttpServerResponse response, String path, Exception e) { Log.e(getClass().getSimpleName(), "Invalid URL: " + path, e); response.code(404); response.end(); } } private class WebSocketClientCallback implements AsyncHttpServer.WebSocketRequestCallback { @Override public void onConnected(final WebSocket ws, AsyncHttpServerRequest request) { sockets.add(ws); ws.setClosedCallback(new CompletedCallback() { @Override public void onCompleted(Exception ex) { if (ex != null) { Log.e(getClass().getSimpleName(), "Exception with WebSocket", ex); } sockets.remove(ws); } }); } } static class ServerStartedEvent { private ArrayList<String> urls = new ArrayList<String>(); void addUrl(String url) { urls.add(url); } ArrayList<String> getUrls() { return (urls); } } static class ServerStoppedEvent { } }