Android客户端套接字，如何读取数据？

Question

以下是我的完整代码：已经建立了连接，我正在向服务器发送数据，但我无法从服务器读取任何内容...

public class client extends Activity
{
    /** Called when the activity is first created. */
    Socket sock;
    String spliter = "**";
    String mobileNbr = "100";
    String LastJOKEId = "-1";
    String spliterlast = "^^$$";
    BufferedReader inFromServer;
    DataOutputStream outToServer;
    TextView cnx;
    TextView output;

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        setupNetworking();
        // Thread readerThread=new Thread(new IncomingReader());
        // readerThread.start();
    }

    private void setupNetworking()
    {
        try
        {
            Log.i("ClientActivity", "Connecting...");
            sock = new Socket("192.168.153.221", 9003);
            cnx = (TextView) findViewById(R.id.textView1);
            cnx.setText("Network Established.");
            inFromServer = new BufferedReader(new InputStreamReader(sock.getInputStream()));
            Log.i("ClientActivity", "Sending command.");
            outToServer = new DataOutputStream(sock.getOutputStream());
            String sentence = "logins" + spliter + mobileNbr + spliter + LastJOKEId + spliterlast;
            outToServer.writeBytes(sentence + '\n');
            Log.i("ClientActivity", "Sent.");
        }
        catch (UnknownHostException e)
        {
            e.printStackTrace();
        }
        catch (IOException e)
        {
            cnx = (TextView) findViewById(R.id.textView1);
            cnx.setText("Network failed");
            e.printStackTrace();
        }
    }

    public class IncomingReader implements Runnable
    {
        String message;
        public void run()
        {
            try
            {
                while ((message = inFromServer.readLine()) != null)
                {
                    output = (TextView) findViewById(R.id.textView2);
                    output.setText(message);
                }
            }
            catch (IOException e)
            {
                output = (TextView) findViewById(R.id.textView2);
                output.setText("nth to display");
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
}

- AnthonyK

---

我什么也没得到:S 什么都没有发生... - AnthonyK

你调试过这部分代码吗？你是如何声明/处理inFromServer的？你应该尝试捕获Exception而不是IOException，因为很容易出现NullPointerException。此外，如果你的最后一行是一个空白字符串，你的TextView将不会显示任何内容。你应该尝试使用append而不是setText。 - rekaszeru

谢谢rekaszeru...你给了我解决问题的提示。它起作用了，现在我可以读取我的数据:D - AnthonyK

Answer 1

package some;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

public class NetClient {

    /**
     * Maximum size of buffer
     */
    public static final int BUFFER_SIZE = 2048;
    private Socket socket = null;
    private PrintWriter out = null;
    private BufferedReader in = null;
    
    private String host = null;
    private String macAddress = null;
    private int port = 7999;
    
    
    /**
     * Constructor with Host, Port and MAC Address
     * @param host
     * @param port
     * @param macAddress
     */
    public NetClient(String host, int port, String macAddress) {
        this.host = host;
        this.port = port;
        this.macAddress = macAddress;
    }
    
    private void connectWithServer() {
        try {
            if (socket == null) {
                socket = new Socket(this.host, this.port);
                out = new PrintWriter(socket.getOutputStream());
                in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    
    private void disConnectWithServer() {
        if (socket != null) {
            if (socket.isConnected()) {
                try {
                    in.close();
                    out.close();
                    socket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
    
    public void sendDataWithString(String message) {
        if (message != null) {
            connectWithServer();
            out.write(message);
            out.flush();
        }
    }
    
    public String receiveDataFromServer() {
        try {
            String message = "";
            int charsRead = 0;
            char[] buffer = new char[BUFFER_SIZE];
            
            while ((charsRead = in.read(buffer)) != -1) {
                message += new String(buffer).substring(0, charsRead);
            }
            
            disConnectWithServer(); // disconnect server
            return message;
        } catch (IOException e) {
            return "Error receiving response:  " + e.getMessage();
        }
    }
    
    
}

//---------------------------使用NetClient------------------------------------------------

NetClient nc = new NetClient(host, port, mac); //mac address maybe not for you
nc.sendDataWithString("your data");
String r = nc.receiveDataFromServer();

这是我们的Android套接字客户端，与Python服务器套接字配合良好，希望它能对您有所帮助。

- Nafiz

Answer 2

HttpResponse response = m_httpClient.execute( request );
String result = "";
if( response.getStatusLine().getStatusCode() == HttpStatus.SC_OK )
{
// open stream
      InputStream stream = response.getEntity().getContent();

      if( stream != null )
      {
        int len = 0;
        byte[] buf = new byte[ 1024 ];

        try
        {
          ByteArrayOutputStream outputStream = new ByteArrayOutputStream();

          while( ( len = stream.read( buf ) ) > 0 )
          {
            outputStream.write( buf, 0, len );
          }

          buf = outputStream.toByteArray();
          result = EncodingUtils.getAsciiString( buf );
        }
        catch( IOException e )
        {
          e.printStackTrace();
        }
        finally
        {
          stream.close();
        }
}

- Pasha