安卓无线网络:处理程序消息不起作用

Question

我想问一个关于我在 Wifi 客户端通信中的代码的问题。我正在与树莓派作为服务器进行通信。 我的代码的体系结构是：

• 主要活动：我有处理程序类，我在OnCreat中启动了第一个线程(Thread1(，它负责建立wifi连接。

  public class MainActivity extends AppCompatActivity {
  public int serverPort = 40000;
  public String serverIP = "10.177.86.212";
  public WiFiConnector wifiConnection;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  editTextWE = (EditText) findViewById(R.id.editText_WE);
  wifiConnection = new WiFiConnector(serverIP, serverPort);
  Handler mHandler = new MyHandler();
  WiFiConnector.Thread1 = new Thread(new WiFiConnector.Thread1(mHandler,true));
  WiFiConnector.Thread1.start();
  }
  private class MyHandler extends Handler {
  private byte[] bytes = null;
  @Override
  public void handleMessage(Message msg) {
  bytes = msg.getData().getByteArray("KEY");
  if(bytes!= null){
  for (int i = 0; i < bytes.length; i++){
  Log.d("Data received", "value " + (0xFF & bytes[i]) );
  }
  for (int i=0; i<bytes.length; i++) {
  editTextWE.setText(editTextWE.getText()+ "Server says: " + bytes.length + " "+ (0xFF & bytes[i]) + "n");
  }
  }
  }
  }
  }
  

  • WifiConnector 类：Thread1 和 Thread2 共享来自 Main Activity 的处理程序。Thread1 向 Raspberry Pi 发送命令，让它开始发送数据。Thread2 专用于读取从服务器接收的数据。

    public class WiFiConnector {
    static String serverIP;
    static int serverPort;
    public static Thread Thread1 = null;
    //Constructor
    public WiFiConnector(String IP, int port) {
    serverIP = IP;
    serverPort = port;
    }
    public static class Thread1 extends Thread implements Runnable {
    private Handler handler1;
    boolean firsttime = false;
    OutputStream out ;
    public Thread1(Handler handler_1, boolean firsttime) {
    this.handler1 = handler_1;
    this.firsttime = firsttime;
    }
    public void run() {
    Socket socket = null;
    try {
    //Writing to a Socket
    InetAddress serverAddress = InetAddress.getByName(serverIP);
    socket = new Socket(serverAddress, serverPort);
    out = new DataOutputStream(socket.getOutputStream());
    if(firsttime){
    //I send "B" to Raspberry to let him start sending data
    out.write("B".getBytes());
    this.fisrttime = false;
    }
    Thread2 comThread = new Thread2(socket, handler1);
    new Thread(comThread).start();
    } catch (UnknownHostException e) {
    e.printStackTrace();
    } catch (IOException e) {
    e.printStackTrace();
    }
    }
    }
    public static class Thread2 implements Runnable {
    public Socket clientSocket;
    private Handler handler_2;
    public DataInputStream in;
    public byte[] bytes = new byte[13];
    public Message msg;
    public Thread2(Socket clientSocket, Handler handler2) {
    this.clientSocket = clientSocket;
    this.handler_2 = handler2;
    }
    public void run() {
    while (!Thread.currentThread().isInterrupted()) {
    try {
    if (Looper.myLooper() == null) {
    Looper.prepare();
    }
    this.in = new DataInputStream(clientSocket.getInputStream());
    in.readFully(bytes);
    if (in != null) {
    for (int i = 0; i < bytes.length; i++){
    Log.d("Data received", "valuewifi " + (0xFF & bytes[i]) );
    }
    msg = new Message();
    Bundle b = new Bundle();
    b.putByteArray("KEY", bytes);
    msg.setData(b);
    handler_2.sendMessage(msg);
    } else {
    Thread1 = new Thread(new Thread1(handler_2,false));
    Thread1.start();
    return;
    }
    } catch (IOException e) {
    e.printStackTrace();
    }
    }
    Looper.loop();
    }
    }
    }
    

现在的问题是： 我从Raspberry Pi正确接收了我的数据(每个包13字节(，确实：

Log.d("Data received", "valuewifi " + (0xFF & bytes[i]) );

正确打印我的值。然后，我创建要发送到 MainActivity 中的处理程序的消息。捆绑包包含(我已经验证(收到的输入流的相同值，但消息打印在 MainActivity 的处理程序中：

Log.d("Data received", "value " + (0xFF & bytes[i]) );

将每条消息的第一个字节值(我试图与 RPi 的每个通信获取 2 个包(替换为 66，这实际上是我发送的"B"的 ASCII 代码，用于启动从 Raspberry Pi 发送的数据。

请问您知道为什么会发生这种情况吗？ 非常感谢您的帮助！:)

Answer 1

好吧，我发现在 Thread2 中如果我把

public byte[] bytes = new byte[13];

在运行{..}之前

in.readFully(bytes);

信息交换完美地发生。否则，我只会在主活动中获取从服务器收到的最后一个字节包。

关于为什么会发生这种情况的任何建议？ 谢谢！