通过互联网连接 2 台安卓设备

Question

我正在尝试连接 2 台 android 设备（中间没有服务器，就像点对点一样），它们连接到互联网（它们相距很远）并发送消息。

我认为它就像普通的套接字编程，并且通过 IP 连接，似乎不是。

到目前为止我所做的是：

我创建了 2 个 android 项目，服务器（接收方）和客户端（发送方）

在 2 个独立的设备中运行

两台设备都连接到互联网

找到运行服务器应用程序的设备的 IP（使用 whatismyip.com） 并在客户端应用程序代码中使用它

但是当我想从客户端向服务器发送文本时，客户端打印 Error3 时发生异常

这是我的代码： 服务器：

   public class MainActivity extends Activity {

   ServerSocket ss = null;
   String mClientMsg = "";
   Thread myCommsThread = null;
   protected static final int MSG_ID = 0x1337;
   public static final int SERVERPORT = 6000;

   @Override
   public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    TextView tv = (TextView) findViewById(R.id.TextView01);
    tv.setText("Nothing from client yet");
    this.myCommsThread = new Thread(new CommsThread());
    this.myCommsThread.start();
   }

   @Override
   protected void onStop() {
    super.onStop();
    try {
        // make sure you close the socket upon exiting
        ss.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
   }

   Handler myUpdateHandler = new Handler() {
    public void handleMessage(Message msg) {
        switch (msg.what) {
        case MSG_ID:
            TextView tv = (TextView) findViewById(R.id.TextView01);
            tv.setText(mClientMsg);
            break;
        default:
            break;
        }
        super.handleMessage(msg);
    }
   };
   class CommsThread implements Runnable {
    public void run() {
        Socket s = null;
        try {
            ss = new ServerSocket(SERVERPORT );
        } catch (IOException e) {
            e.printStackTrace();
        }
        while (!Thread.currentThread().isInterrupted()) {
            Message m = new Message();
            m.what = MSG_ID;
            try {
                if (s == null)
                    s = ss.accept();
                BufferedReader input = new BufferedReader(new InputStreamReader(s.getInputStream()));
                String st = null;
                st = input.readLine();
                mClientMsg = st;
                myUpdateHandler.sendMessage(m);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    }
}

客户端（错误 3）：

   public class MainActivity extends Activity {

   private Button bt;
   private TextView tv;
   private Socket socket;
   private String serverIpAddress = "5.114.22.118";
   // AND THAT'S MY DEV'T MACHINE WHERE PACKETS TO
   // PORT 5000 GET REDIRECTED TO THE SERVER EMULATOR'S
   // PORT 6000
   private static final int REDIRECTED_SERVERPORT = 80;

   @Override
   public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      bt = (Button) findViewById(R.id.myButton);
      tv = (TextView) findViewById(R.id.myTextView);

      new Thread(new ClientThread()).start();

      bt.setOnClickListener(new OnClickListener() {
         public void onClick(View v) {
            try {
               EditText et = (EditText) findViewById(R.id.EditText01);
               String str = et.getText().toString();
               PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);
               out.println(str);
               Log.d("Client", "Client sent message");
            } catch (UnknownHostException e) {
               tv.setText("Error1");
               e.printStackTrace();
            } catch (IOException e) {
               tv.setText("Error2");
               e.printStackTrace();
            } catch (Exception e) {
               tv.setText("Error3");
               e.printStackTrace();
            }
         }
      });
   }

   class ClientThread implements Runnable {

       @Override
       public void run() {
           try {
                 InetAddress serverAddr = InetAddress.getByName(serverIpAddress);
                 socket = new Socket(serverAddr, REDIRECTED_SERVERPORT);
              } catch (UnknownHostException e1) {
                 e1.printStackTrace();
              } catch (IOException e1) {
                 e1.printStackTrace();
              }
       }
   }

}

Answer 1

我认为这更适合作为评论，但我没有足够的声誉发表评论，所以我将其作为答案提供。您的服务器是否连接到路由器？ whatismyip.com 返回路由器的 IP 地址，而不是设备。