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}); });});
