本地PC服务器和android仿真器之间的套接字连接

Question

I have troubles with socket connection of PC (simple server written on Java) and android emulator. Connection is established, server sends data but when I try to read it on android it always reads a null-string. Here is some parts of my code:

Server:

serverSocket = new ServerSocket(8888);
socket = serverSocket.accept();
PrintWriter output = new PrintWriter(socket.getOutputStream(), true);
output.write("Output string");
socket.close();

Client:

socket = new Socket("10.0.2.2", 8888);
input = new BufferedReader(new InputStreamReader(socket.getInputStream()));
String s = input.readLine();
Log.i(TAG, s);
socket.close();

I've omitted try-catches and logs for clearness. According to logs, connection is established, server sends data, but client receives only null-strings. I'd appreciate any help.

Answer 1

This works for me... (This code only for write and read data from socket for both server and client)

Server:

  BufferedOutputStream bos = new BufferedOutputStream(connection.
      getOutputStream());

  /** Instantiate an OutputStreamWriter object with the optional character
   * encoding.
   */
  OutputStreamWriter osw = new OutputStreamWriter(bos, "US-ASCII");

  String process = "Calling the Socket Server on "+ host + " port " + port;

  /** Write across the socket connection and flush the buffer */
  osw.write(process);
  osw.flush();

Client:

 /** Instantiate a BufferedInputStream object for reading
      /** Instantiate a BufferedInputStream object for reading
       * incoming socket streams.
       */

      BufferedInputStream bis = new BufferedInputStream(connection.
          getInputStream());
      /**Instantiate an InputStreamReader with the optional
       * character encoding.
       */

      InputStreamReader isr = new InputStreamReader(bis, "US-ASCII");

      /**Read the socket's InputStream and append to a StringBuffer */
      int c;
      while ( (c = isr.read()) != 13)
        instr.append( (char) c);

      /** Close the socket connection. */
      connection.close();
      System.out.println(instr);
     }
    catch (IOException f) {
      System.out.println("IOException: " + f);
    }
    catch (Exception g) {
      System.out.println("Exception: " + g);
    }

Hope this will help you..

Answer 2

hi @yuriy nothing is wrong with your code actually your not writing full line to output stream so its giving error use it it worked for me

 serverSocket = new ServerSocket(8888);
    socket = serverSocket.accept();
    PrintWriter output = new PrintWriter(socket.getOutputStream(), true);
   output.println("Output string");
    socket.close();

just replace output.write with output.println in server

Answer 3

Emulator listen his "own" local network ports. You should call port forward from your local pc to emulator ports.

Read android adb port forwarding.