Java tutorial
/* * Copyright 2016 The WebRTC Project Authors. All rights reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be found * in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ package org.appspot.apprtc; import android.util.Log; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import org.webrtc.IceCandidate; import org.webrtc.PeerConnection; import org.webrtc.SessionDescription; import java.util.LinkedList; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.regex.Matcher; import java.util.regex.Pattern; /** * Implementation of AppRTCClient that uses direct TCP connection as the signaling channel. * This eliminates the need for an external server. This class does not support loopback * connections. */ public class DirectRTCClient implements AppRTCClient, TCPChannelClient.TCPChannelEvents { private static final String TAG = "DirectRTCClient"; private static final int DEFAULT_PORT = 8888; // Regex pattern used for checking if room id looks like an IP. static final Pattern IP_PATTERN = Pattern.compile("(" // IPv4 + "((\\d+\\.){3}\\d+)|" // IPv6 + "\\[((([0-9a-fA-F]{1,4}:)*[0-9a-fA-F]{1,4})?::" + "(([0-9a-fA-F]{1,4}:)*[0-9a-fA-F]{1,4})?)\\]|" + "\\[(([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4})\\]|" // IPv6 without [] + "((([0-9a-fA-F]{1,4}:)*[0-9a-fA-F]{1,4})?::(([0-9a-fA-F]{1,4}:)*[0-9a-fA-F]{1,4})?)|" + "(([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4})|" // Literals + "localhost" + ")" // Optional port number + "(:(\\d+))?"); private final ExecutorService executor; private final SignalingEvents events; private TCPChannelClient tcpClient; private RoomConnectionParameters connectionParameters; private enum ConnectionState { NEW, CONNECTED, CLOSED, ERROR } // All alterations of the room state should be done from inside the looper thread. private ConnectionState roomState; public DirectRTCClient(SignalingEvents events) { this.events = events; executor = Executors.newSingleThreadExecutor(); roomState = ConnectionState.NEW; } /** * Connects to the room, roomId in connectionsParameters is required. roomId must be a valid * IP address matching IP_PATTERN. */ @Override public void connectToRoom(RoomConnectionParameters connectionParameters) { this.connectionParameters = connectionParameters; if (connectionParameters.loopback) { reportError("Loopback connections aren't supported by DirectRTCClient."); } executor.execute(new Runnable() { @Override public void run() { connectToRoomInternal(); } }); } @Override public void disconnectFromRoom() { executor.execute(new Runnable() { @Override public void run() { disconnectFromRoomInternal(); } }); } /** * Connects to the room. * * Runs on the looper thread. */ private void connectToRoomInternal() { this.roomState = ConnectionState.NEW; String endpoint = connectionParameters.roomId; Matcher matcher = IP_PATTERN.matcher(endpoint); if (!matcher.matches()) { reportError("roomId must match IP_PATTERN for DirectRTCClient."); return; } String ip = matcher.group(1); String portStr = matcher.group(matcher.groupCount()); int port; if (portStr != null) { try { port = Integer.parseInt(portStr); } catch (NumberFormatException e) { reportError("Invalid port number: " + portStr); return; } } else { port = DEFAULT_PORT; } tcpClient = new TCPChannelClient(executor, this, ip, port); } /** * Disconnects from the room. * * Runs on the looper thread. */ private void disconnectFromRoomInternal() { roomState = ConnectionState.CLOSED; if (tcpClient != null) { tcpClient.disconnect(); tcpClient = null; } executor.shutdown(); } @Override public void sendOfferSdp(final SessionDescription sdp) { executor.execute(new Runnable() { @Override public void run() { if (roomState != ConnectionState.CONNECTED) { reportError("Sending offer SDP in non connected state."); return; } JSONObject json = new JSONObject(); jsonPut(json, "sdp", sdp.description); jsonPut(json, "type", "offer"); sendMessage(json.toString()); } }); } @Override public void sendAnswerSdp(final SessionDescription sdp) { executor.execute(new Runnable() { @Override public void run() { JSONObject json = new JSONObject(); jsonPut(json, "sdp", sdp.description); jsonPut(json, "type", "answer"); sendMessage(json.toString()); } }); } @Override public void sendLocalIceCandidate(final IceCandidate candidate) { executor.execute(new Runnable() { @Override public void run() { JSONObject json = new JSONObject(); jsonPut(json, "type", "candidate"); jsonPut(json, "label", candidate.sdpMLineIndex); jsonPut(json, "id", candidate.sdpMid); jsonPut(json, "candidate", candidate.sdp); if (roomState != ConnectionState.CONNECTED) { reportError("Sending ICE candidate in non connected state."); return; } sendMessage(json.toString()); } }); } /** Send removed Ice candidates to the other participant. */ @Override public void sendLocalIceCandidateRemovals(final IceCandidate[] candidates) { executor.execute(new Runnable() { @Override public void run() { JSONObject json = new JSONObject(); jsonPut(json, "type", "remove-candidates"); JSONArray jsonArray = new JSONArray(); for (final IceCandidate candidate : candidates) { jsonArray.put(toJsonCandidate(candidate)); } jsonPut(json, "candidates", jsonArray); if (roomState != ConnectionState.CONNECTED) { reportError("Sending ICE candidate removals in non connected state."); return; } sendMessage(json.toString()); } }); } // ------------------------------------------------------------------- // TCPChannelClient event handlers /** * If the client is the server side, this will trigger onConnectedToRoom. */ @Override public void onTCPConnected(boolean isServer) { if (isServer) { roomState = ConnectionState.CONNECTED; SignalingParameters parameters = new SignalingParameters( // Ice servers are not needed for direct connections. new LinkedList<PeerConnection.IceServer>(), isServer, // Server side acts as the initiator on direct connections. null, // clientId null, // wssUrl null, // wwsPostUrl null, // offerSdp null // iceCandidates ); events.onConnectedToRoom(parameters); } } @Override public void onTCPMessage(String msg) { try { JSONObject json = new JSONObject(msg); String type = json.optString("type"); if (type.equals("candidate")) { events.onRemoteIceCandidate(toJavaCandidate(json)); } else if (type.equals("remove-candidates")) { JSONArray candidateArray = json.getJSONArray("candidates"); IceCandidate[] candidates = new IceCandidate[candidateArray.length()]; for (int i = 0; i < candidateArray.length(); ++i) { candidates[i] = toJavaCandidate(candidateArray.getJSONObject(i)); } events.onRemoteIceCandidatesRemoved(candidates); } else if (type.equals("answer")) { SessionDescription sdp = new SessionDescription(SessionDescription.Type.fromCanonicalForm(type), json.getString("sdp")); events.onRemoteDescription(sdp); } else if (type.equals("offer")) { SessionDescription sdp = new SessionDescription(SessionDescription.Type.fromCanonicalForm(type), json.getString("sdp")); SignalingParameters parameters = new SignalingParameters( // Ice servers are not needed for direct connections. new LinkedList<PeerConnection.IceServer>(), false, // This code will only be run on the client side. So, we are not the initiator. null, // clientId null, // wssUrl null, // wssPostUrl sdp, // offerSdp null // iceCandidates ); roomState = ConnectionState.CONNECTED; events.onConnectedToRoom(parameters); } else { reportError("Unexpected TCP message: " + msg); } } catch (JSONException e) { reportError("TCP message JSON parsing error: " + e.toString()); } } @Override public void onTCPError(String description) { reportError("TCP connection error: " + description); } @Override public void onTCPClose() { events.onChannelClose(); } // -------------------------------------------------------------------- // Helper functions. private void reportError(final String errorMessage) { Log.e(TAG, errorMessage); executor.execute(new Runnable() { @Override public void run() { if (roomState != ConnectionState.ERROR) { roomState = ConnectionState.ERROR; events.onChannelError(errorMessage); } } }); } private void sendMessage(final String message) { executor.execute(new Runnable() { @Override public void run() { tcpClient.send(message); } }); } // Put a |key|->|value| mapping in |json|. private static void jsonPut(JSONObject json, String key, Object value) { try { json.put(key, value); } catch (JSONException e) { throw new RuntimeException(e); } } // Converts a Java candidate to a JSONObject. private static JSONObject toJsonCandidate(final IceCandidate candidate) { JSONObject json = new JSONObject(); jsonPut(json, "label", candidate.sdpMLineIndex); jsonPut(json, "id", candidate.sdpMid); jsonPut(json, "candidate", candidate.sdp); return json; } // Converts a JSON candidate to a Java object. private static IceCandidate toJavaCandidate(JSONObject json) throws JSONException { return new IceCandidate(json.getString("id"), json.getInt("label"), json.getString("candidate")); } }