我找到了一个写得很好的教程 here用于android上的服务器客户端通信。奇迹般有效。但这只是一种沟通方式。我正在尝试在客户端中收听服务器响应，但不知道我哪里错了。这是我尝试进行更改的服务器代码。

服务器

public class Server extends Activity {

    private ServerSocket serverSocket;

    Handler updateConversationHandler;

    Thread serverThread = null;

    private TextView text;



    public static final int SERVERPORT = 8080;

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        text = (TextView) findViewById(R.id.text2);

        updateConversationHandler = new Handler();

        this.serverThread = new Thread(new ServerThread());
        this.serverThread.start();

    }

    @Override
    protected void onStop() {
        super.onStop();
        try {
            serverSocket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    class ServerThread implements Runnable {

        public void run() {
            Socket socket = null;
            try {
                serverSocket = new ServerSocket(SERVERPORT);
            } catch (IOException e) {
                e.printStackTrace();
            }
            while (!Thread.currentThread().isInterrupted()) {

                try {

                    socket = serverSocket.accept();

                    CommunicationThread commThread = new CommunicationThread(socket);
                    new Thread(commThread).start();

                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    class CommunicationThread implements Runnable {

        private Socket clientSocket;

        private BufferedReader input;

        public CommunicationThread(Socket clientSocket) {

            this.clientSocket = clientSocket;

            try {

                this.input = new BufferedReader(new InputStreamReader(this.clientSocket.getInputStream()));
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        public void run() {


            while (!Thread.currentThread().isInterrupted()) {

                try {

                    String read = input.readLine();

                     if (read == null ){
                         Thread.currentThread().interrupt();
                     }else{
                         BufferedWriter out = new BufferedWriter(new OutputStreamWriter(clientSocket.getOutputStream()));
                         out.write("TstMsg");
                         updateConversationHandler.post(new updateUIThread(read));

                     }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

    }

    class updateUIThread implements Runnable {
        private String msg;

        public updateUIThread(String str) {
            this.msg = str;
        }

        @Override
        public void run() {
            text.setText("Client Says: "+ msg + new Date() + "\n");

        }

    }

}

客户端

public class Client extends Activity {

    private Socket socket;

    private static final int SERVERPORT = 8080;
    private static final String SERVER_IP = "192.168.104.107";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);      
                    new Thread(new ClientThread()).start();

    }


    public void onClick(View view) {
        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);
            out.flush();
            BufferedReader  in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            String read = in.readLine();
            System.out.println("MSG:" + read);  

        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    class ClientThread implements Runnable {

        @Override
        public void run() {

            try {
                InetAddress serverAddr = InetAddress.getByName(SERVER_IP);
                socket = new Socket(serverAddr, SERVERPORT);

            } catch (UnknownHostException e1) {
                e1.printStackTrace();
            } catch (IOException e1) {
                e1.printStackTrace();
            }

        }

    }
}

更新

当客户端向服务器发送任何消息时，服务器会收到消息，但当服务器发送响应时

BufferedWriter out = new BufferedWriter(new OutputStreamWriter(clientSocket.getOutputStream()));
 out.write("TstMsg");

在客户端

String read = in.readLine();
System.out.println("MSG:" + read); 

它没有被客户端接收到，或者我们可以说服务器监听客户端消息但客户端没有。 我在 list 中添加了这两个权限。

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

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

更新 长时间挂起后出现这些错误。

11-28 18:35:45.786: E/GTalkService(292): connectionClosed: no XMPPConnection - That's strange!
11-28 18:35:48.806: D/ConnectivityService(148): handleInetConditionHoldEnd: net=1, condition=0, published condition=0
11-28 18:35:54.526: I/GTalkService/c(292): [AndroidEndpoint@1090563472] connect: acct=1000000, state=CONNECTING
11-28 18:35:55.176: D/dalvikvm(1167): GC_CONCURRENT freed 495K, 9% free 6604K/7239K, paused 2ms+3ms
11-28 18:35:55.226: D/Finsky(1167): [1] 5.onFinished: Installation state replication succeeded.
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349): Problem with socket or streams.
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349): java.net.ConnectException: failed to connect to www.google-analytics.com/173.194.39.41 (port 80): connect failed: ETIMEDOUT (Connection timed out)
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349):  at libcore.io.IoBridge.connect(IoBridge.java:114)
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349):  at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349):  at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349):  at java.net.Socket.connect(Socket.java:842)
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349):  at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119)
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349):  at com.google.android.apps.analytics.t.run(Unknown Source)
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349):  at android.os.Handler.handleCallback(Handler.java:605)
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349):  at android.os.Handler.dispatchMessage(Handler.java:92)
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349):  at android.os.Looper.loop(Looper.java:137)
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349):  at android.os.HandlerThread.run(HandlerThread.java:60)
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349): Caused by: libcore.io.ErrnoException: connect failed: ETIMEDOUT (Connection timed out)
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349):  at libcore.io.Posix.connect(Native Method)
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349):  at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:85)
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349):  at libcore.io.IoBridge.connectErrno(IoBridge.java:127)
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349):  at libcore.io.IoBridge.connect(IoBridge.java:112)
11-28 18:37:18.276: W/GoogleAnalyticsTracker(349):  ... 9 more
11-28 18:37:29.016: D/dalvikvm(349): GC_CONCURRENT freed 1258K, 35% free 8238K/12487K, paused 2ms+8ms

最佳答案

readLine() expects an actual line :' 一行被认为由换行符 ('\n')、回车符 ('\r') 或回车符中的任何一个终止一个换行符。'

因此，您应该发送一个，例如。使用 BufferedWriter.newLine()。

关于java - Android TCP 服务器客户端通信，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/20263522/