Android应用程序使用Socket.io连接到Node.js服务器

Question

我无法让我的Android应用程序连接到socket.io聊天服务器。我正在使用由Gottox创建的socket.io-java-
client，可以在这里找到：https :
//github.com/Gottox/socket.io-java-
client

服务器在端口7000上本地运行。我使用的是Android模拟器，因此我使用的是10.0.2.2:7000来访问服务器。

任何帮助将不胜感激，我对SSL没有任何经验。如果找到有效的解决方案，我也会将其发布。

Node.js服务器

var express = require('express');
var app = express();
var server = require('http').createServer(app).listen(7000);
var io = require('socket.io').listen(server);
io.sockets.on('connection', function(client){
    client.on('message', function(err, msg){
        client.broadcast.emit('message', msg);
    });
 });

package.json

{
  "name": "simplechat",
  "version": "0.0.1",
  "main": "app.js",
  "dependencies": {
    "express" : "~4.0.0",
    "socket.io" : "~0.9.13"
  }
}

Android：SendMessageActivity

public class SendMessageActivity extends Activity {

    private static final String SERVER_ADDRESS = "https://10.0.2.2:7000";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_send_message);

        System.out.println("Sever: " + SERVER_ADDRESS);

        try {
            SocketIO socket = new SocketIO(new URL(SERVER_ADDRESS), new IOCallback() {
                @Override
                public void onDisconnect() {
                    System.out.println("disconnected");
                }

                @Override
                public void onConnect() {
                    System.out.println("connected");
                }

                @Override
                public void onMessage(String s, IOAcknowledge ioAcknowledge) {
                }

                @Override
                public void onMessage(JSONObject jsonObject, IOAcknowledge ioAcknowledge) {
                }

                @Override
                public void on(String event, IOAcknowledge ioAcknowledge, Object... objects) {
                }

                @Override
                public void onError(SocketIOException e) {
                    e.printStackTrace();
                }
            });

        } catch (MalformedURLException ex) {
            ex.printStackTrace();
        }
    }

Android权限

<uses-permission
    android:name="android.permission.INTERNET">
</uses-permission>

错误代码

08-09 16:07:28.224    8411-8441/com.example.puma.chatexample W/System.err﹕ io.socket.SocketIOException: Error while handshaking
08-09 16:07:28.225    8411-8441/com.example.puma.chatexample W/System.err﹕ at io.socket.IOConnection.handshake(IOConnection.java:322)
08-09 16:07:28.225    8411-8441/com.example.puma.chatexample W/System.err﹕ at io.socket.IOConnection.access$600(IOConnection.java:39)
08-09 16:07:28.225    8411-8441/com.example.puma.chatexample W/System.err﹕ at io.socket.IOConnection$ConnectThread.run(IOConnection.java:199)
08-09 16:07:28.226    8411-8441/com.example.puma.chatexample W/System.err﹕ Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'javax.net.ssl.SSLSocketFactory javax.net.ssl.SSLContext.getSocketFactory()' on a null object reference
08-09 16:07:28.226    8411-8441/com.example.puma.chatexample W/System.err﹕ at io.socket.IOConnection.handshake(IOConnection.java:302)
08-09 16:07:28.227    8411-8441/com.example.puma.chatexample W/System.err﹕ ... 2 more

Answer 1

我实际上解决了问题。我使用了PC的本地IP
http://192.168.0.xxx:7000，该应用程序能够从模拟器连接到聊天服务器。我不知道为什么会这样，但是将来可能会对某人有所帮助:)

更新：

这就是我最终构造项目的方式。我创建了一个singleton类来处理Android端的套接字连接（您也可以将其作为服务来完成）。收到消息时，单例类向其他应用程序广播一个意图。然后由广播接收者在相关活动中获取意图。

Android Side（单人）：

public class SocketSingleton {

    private static SocketSingleton instance;
    private static final String SERVER_ADDRESS = "http://1.2.3.4:1234";
    private SocketIO socket;
    private Context context;

    public static SocketSingleton get(Context context){
        if(instance == null){
            instance = getSync(context);
        }
        instance.context = context;
        return instance;
    }

    public static synchronized SocketSingleton getSync(Context context){
        if (instance == null) {
            instance = new SocketSingleton(context);
        }
        return instance;
    }

    public SocketIO getSocket(){
        return this.socket;
    }

    private SocketSingleton(Context context){
        this.context = context;
        this.socket = getChatServerSocket();
        this.friends = new ArrayList<Friend>();
    }

    private SocketIO getChatServerSocket(){
        try {
            SocketIO socket = new SocketIO(new URL(SERVER_ADDRESS), new IOCallback() {
                @Override
                public void onDisconnect() {
                    System.out.println("disconnected");
                }

                @Override
                public void onConnect() {
                    System.out.println("connected");
                }

                @Override
                public void on(String event, IOAcknowledge ioAcknowledge, Object... objects) {
                    if (event.equals("chatMessage")) {
                        JSONObject json = (JSONObject) objects[0];
                        ChatMessage chatMessage = new ChatMessage(json);

                        Intent intent = new Intent();
                        intent.setAction("newChatMessage");
                        intent.putExtra("chatMessage", chatMessage);
                        context.sendBroadcast(intent);
                    }
                }
                @Override
                public void onError(SocketIOException e) {
                    e.printStackTrace();
                }
            });
            return socket;
        } catch (MalformedURLException ex) {
            ex.printStackTrace();
        }
        return null;
    }
}

Android Side（活动）：

public class ChatActivity extends Activity {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_chat);
    IntentFilter newChatMessageFilter = new IntentFilter("newChatMessage");
    this.registerReceiver(new MessageReceiver(), newChatMessageFilter);

    ...

    public class MessageReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent){
            final ChatMessage chatMessage =(ChatMessage) intent.getExtras().get("chatMessage");
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    mAdapter.add(chatMessage);
                    mAdapter.notifyDataSetChanged();
                }
            });
        }
    }
}

服务器端：

var express = require('express');
var app = express();
var server = require('http').createServer(app).listen(1234);
var io = require('socket.io').listen(server);

io.sockets.on('connection', function(client){

    console.log("client connected: " + client.id);

    client.on("sendTo", function(chatMessage){
        console.log("Message From: " + chatMessage.fromName);
        console.log("Message To: " + chatMessage.toName);


        io.sockets.socket(chatMessage.toClientID).emit("chatMessage", {"fromName" : chatMessage.fromName,
                                                                    "toName" : chatMessage.toName,
                                                                    "toClientID" : chatMessage.toClientID,
                                                                    "msg" : chatMessage.msg});

    });
});