停止網絡接收器線程

假設我有一個NetThread（定義如下）的對象，名爲nt。我已經初始化並啓動它停止網絡接收器線程

nt = new NetThread(port, rs); 
nt.setDaemon(true); 
nt.setPriority(Thread.MAX_PRIORITY); 
nt.start();

現在我希望能夠在執行過程中停止這個線程的任何一點。我可以通過致電nt.interrupt()來完成此操作。

但是，我想我會嘗試做一些更有意義的事情：在NetThread內創建一個名爲StopListening()的方法。

雖然nt正在運行，我打電話nt.StopListening()。沒有。

線程只是繼續運行。我錯過了什麼？爲什麼這不起作用？

public class NetThread extends Thread { 

    int port; 

    private static int PAYLOAD_MAX = 10000; 
    private static int NET_SO_TIMEOUT = 0; 
    private RunStats rs; 

    private boolean stopflag = false; 

    private StageCode stage; 

    NetThread(int port_number, RunStats runstats) 
    { 
     rs = runstats; 
     port = port_number; 
     stage = StageCode.STAGE_WAIT; 
    } 

    public synchronized void stopListening() 
    { 
     Log.d(C.DTAG, "stopListening() was called..."); 
     stopflag=true; 
    } 

    @Override 
    public void run() 
    { 
     receiveData(); 
     Log.d(C.DTAG, "Network thread is finished."); 
    } 

    public void receiveData() 
    { 
     // request permission to do network operations in manifest file...done 

     Log.d(C.DTAG, "network thread has started."); 

     // start the network side of things 
     DatagramSocket sock = null; 
     DatagramPacket pkt = null; 

     try 
     { 
      byte[] data = new byte[PAYLOAD_MAX]; 
      sock = new DatagramSocket(port); 
      sock.setSoTimeout(NET_SO_TIMEOUT); 
      pkt = new DatagramPacket(data, 0, PAYLOAD_MAX); 

      while (!stopflag) 
      { 
       Thread.sleep(0); // allow for an interrupt 
       try 
       { 
        sock.receive(pkt); 
        int length = pkt.getLength(); 
        processPayload(pkt.getData(), length); 
       } 
       catch (InterruptedIOException e) 
       { 
        // thrown when a timeout occurs 
        Log.d(C.DTAG, "net: no packets yet"); 
       } 
      } 
      Log.d(C.DTAG, "done receiving."); 
      if (sock != null) sock.close(); 
     } 
     catch (InterruptedException x) 
     { 
      Log.d(C.DTAG, "net: was interrupted."); 
     } 
     catch (SocketException e) 
     { 
      Log.d(C.DTAG, "net: SocketException"); 
      e.printStackTrace(); 
     } 
     catch (IOException e) 
     { 
      Log.d(C.DTAG, "net: IOException"); 
      e.printStackTrace(); 
     } 
     if (sock != null) sock.close(); 
    } 

    public void processPayload(byte[] data, int length) 
    { 
     if (length < 20) return; 

     int sc = data[ 0] & 0x000000FF | data[ 1]<<8 & 0x0000FF00 | data[ 2]<<16 & 0x00FF0000 | data[ 3]<<24 & 0xFF000000; 
     int seq = data[ 4] & 0x000000FF | data[ 5]<<8 & 0x0000FF00 | data[ 6]<<16 & 0x00FF0000 | data[ 7]<<24 & 0xFF000000; 
     int i =  data[ 8] & 0x000000FF | data[ 9]<<8 & 0x0000FF00 | data[10]<<16 & 0x00FF0000 | data[11]<<24 & 0xFF000000; 
     int s =  data[12] & 0x000000FF | data[13]<<8 & 0x0000FF00 | data[14]<<16 & 0x00FF0000 | data[15]<<24 & 0xFF000000; 
     int n =  data[16] & 0x000000FF | data[17]<<8 & 0x0000FF00 | data[18]<<16 & 0x00FF0000 | data[19]<<24 & 0xFF000000; 

     StageCode sc2 = null; 
     switch (sc) 
     { 
     case 20: sc2 = StageCode.STAGE_INIT; break; 
     case 30: sc2 = StageCode.STAGE_TEST; break; 
     case 40: sc2 = StageCode.STAGE_STOP; break; 
     } 

     TestPacketHeader tph = new TestPacketHeader(sc2, seq, i, s, n); 
     rs.RegisterReceivedPacket(tph); 

     if (sc2 == StageCode.STAGE_STOP) stopflag = true; 
    } 

    public synchronized StageCode status() 
    { 
     return stage; 
    } 
}

來源

2013-12-20 Jared Lindsey