doInBackground 卡住

doInBackground gets stuck

我正在尝试创建一个使用多个端口的服务器,以便可以轻松地发送和接收不同的数据和信息,但是在我的 doInBackground 方法中,我的代码卡在了 socket.receive 上,

这是我的代码

while( run )

  {

    //GameServerID

    try

    {

      if(gameServerID == null)

      {

        gameServerID = new DatagramSocket( portID );

      }

      //try to receive data

      byte[] buf = new byte[256];

      DatagramPacket packet = new DatagramPacket( buf, buf.length );

      try

      {

        Log.d(TAG,"Wait for something to connect");

        gameServerID.receive( packet ); <--GETS STUCK HERE

      }

      catch (IOException e) 

      {

        Log.d(TAG,"Error with receiving data");

        e.printStackTrace();

      }

      String data = new String( buf, 0, packet.getLength() );

      Log.d(TAG, data);

      //Send out the ID to the client

      byte[] bufer = new byte[256];

      //Send a message"connect" to the host

      String msg = Integer.toString( players );

      players = players + 1;

      bufer = msg.getBytes();

      InetAddress address;

      //Default ip address of the host

      address = packet.getAddress();

      DatagramPacket p = new DatagramPacket( bufer, bufer.length , address, portID );

      //Send packet

      gameServerID.send( p );

      addresses.add( address );

    }

    catch (SocketException e) 

    {

      Log.d(TAG,"Error with socket");

      e.printStackTrace();

    } 

    //Listen for a client to connect

    catch (IOException e) 

    {

      Log.d(TAG,"Error with I/O");

      e.printStackTrace();

    }



    //GameServerPositions

    try

    {

      Log.d(TAG,"Run the gamePositions code");

      if(gamePositions == null)

      {

        gamePositions = new DatagramSocket( portPos );

      }

      //Receive position

      //try to receive data

      byte[] buf = new byte[256];

      DatagramPacket packet = new DatagramPacket( buf, buf.length );

      try

      {

        gamePositions.receive( packet );

      }

      catch (IOException e) 

      {

        Log.d(TAG,"Error with receiving data");

        e.printStackTrace();

      }

      String data = new String( buf, 0, packet.getLength() );

      Log.d(TAG, data);

      String[] pos = data.split(":");

      for(int i = 0;i<pos.length;i++)

      {

        Log.d(TAG, pos[i]);

      }

      xValues[ Integer.parseInt( pos[0] ) ] = Integer.parseInt( pos[1] );

      yValues[ Integer.parseInt( pos[0] ) ] = Integer.parseInt( pos[2] );

    }

    catch (SocketException e) 

    {

      Log.d(TAG,"Error with socket");

      e.printStackTrace();

    } 

    //Listen for a client to connect

    catch (IOException e) 

    {

      Log.d(TAG,"Error with I/O");

      e.printStackTrace();

    }



    //GameServerSendPos

    try

    {

      Log.d(TAG,"Run the gamePositionsSend code");

      String data ="";

      if( gameSendPos == null )

      {

        gameSendPos = new DatagramSocket( portSend );

      }



      //create the string ready to be sent out

      for(int i = 0; i < 8; i++)

      {

        if(xValues[i] >= 0)

        {

          data += i +":" + xValues[i] +":" + yValues[i] +":";

        }

      }



      byte[] bufer = new byte[256];

      bufer = data.getBytes();

      DatagramPacket p = null;



      for(int i = 0;i < addresses.size(); i++)

      {

        if( addresses.get(i) != null )

        {

          p = new DatagramPacket( bufer, bufer.length , addresses.get(i), portSend );

          gameSendPos.send( p );

        }

      }



    }

    catch (SocketException e) 

    {

      // TODO Auto-generated catch block

      e.printStackTrace();

    } 

    catch (IOException e) 

    {

      // TODO Auto-generated catch block

      e.printStackTrace();

    }

  }

while( run )

  {

    if(start == true)

    {

      gsID.doInBackground( );

      addresses = gsID.addresses;

      gsPos.addresses = addresses;

      gsPos.doInBackground( );

      gsSendPos.addresses = addresses;

      gsSendPos.positions = gsPos.positions;

      gsSendPos.doInBackground( );

      start = false;

    }

    else

    {

      addresses = gsID.addresses;

      gsPos.addresses = addresses;

      gsSendPos.addresses = addresses;

      gsSendPos.positions = gsPos.positions;

    }

  }

我能做些什么来阻止它卡住,或者在等了这么久之后,只是跳过它?只是为了获取更多信息,当第一个客户端连接时,代码工作正常,直到它再次到达顶部,然后 socket.received 就卡住了......

画布

更新

我已将我的代码更改为 3 个不同的类,我在我的服务器中启动它们,而循环就像这样

while( run )

  {

    //GameServerID

    try

    {

      if(gameServerID == null)

      {

        gameServerID = new DatagramSocket( portID );

      }

      //try to receive data

      byte[] buf = new byte[256];

      DatagramPacket packet = new DatagramPacket( buf, buf.length );

      try

      {

        Log.d(TAG,"Wait for something to connect");

        gameServerID.receive( packet ); <--GETS STUCK HERE

      }

      catch (IOException e) 

      {

        Log.d(TAG,"Error with receiving data");

        e.printStackTrace();

      }

      String data = new String( buf, 0, packet.getLength() );

      Log.d(TAG, data);

      //Send out the ID to the client

      byte[] bufer = new byte[256];

      //Send a message"connect" to the host

      String msg = Integer.toString( players );

      players = players + 1;

      bufer = msg.getBytes();

      InetAddress address;

      //Default ip address of the host

      address = packet.getAddress();

      DatagramPacket p = new DatagramPacket( bufer, bufer.length , address, portID );

      //Send packet

      gameServerID.send( p );

      addresses.add( address );

    }

    catch (SocketException e) 

    {

      Log.d(TAG,"Error with socket");

      e.printStackTrace();

    } 

    //Listen for a client to connect

    catch (IOException e) 

    {

      Log.d(TAG,"Error with I/O");

      e.printStackTrace();

    }



    //GameServerPositions

    try

    {

      Log.d(TAG,"Run the gamePositions code");

      if(gamePositions == null)

      {

        gamePositions = new DatagramSocket( portPos );

      }

      //Receive position

      //try to receive data

      byte[] buf = new byte[256];

      DatagramPacket packet = new DatagramPacket( buf, buf.length );

      try

      {

        gamePositions.receive( packet );

      }

      catch (IOException e) 

      {

        Log.d(TAG,"Error with receiving data");

        e.printStackTrace();

      }

      String data = new String( buf, 0, packet.getLength() );

      Log.d(TAG, data);

      String[] pos = data.split(":");

      for(int i = 0;i<pos.length;i++)

      {

        Log.d(TAG, pos[i]);

      }

      xValues[ Integer.parseInt( pos[0] ) ] = Integer.parseInt( pos[1] );

      yValues[ Integer.parseInt( pos[0] ) ] = Integer.parseInt( pos[2] );

    }

    catch (SocketException e) 

    {

      Log.d(TAG,"Error with socket");

      e.printStackTrace();

    } 

    //Listen for a client to connect

    catch (IOException e) 

    {

      Log.d(TAG,"Error with I/O");

      e.printStackTrace();

    }



    //GameServerSendPos

    try

    {

      Log.d(TAG,"Run the gamePositionsSend code");

      String data ="";

      if( gameSendPos == null )

      {

        gameSendPos = new DatagramSocket( portSend );

      }



      //create the string ready to be sent out

      for(int i = 0; i < 8; i++)

      {

        if(xValues[i] >= 0)

        {

          data += i +":" + xValues[i] +":" + yValues[i] +":";

        }

      }



      byte[] bufer = new byte[256];

      bufer = data.getBytes();

      DatagramPacket p = null;



      for(int i = 0;i < addresses.size(); i++)

      {

        if( addresses.get(i) != null )

        {

          p = new DatagramPacket( bufer, bufer.length , addresses.get(i), portSend );

          gameSendPos.send( p );

        }

      }



    }

    catch (SocketException e) 

    {

      // TODO Auto-generated catch block

      e.printStackTrace();

    } 

    catch (IOException e) 

    {

      // TODO Auto-generated catch block

      e.printStackTrace();

    }

  }

while( run )

  {

    if(start == true)

    {

      gsID.doInBackground( );

      addresses = gsID.addresses;

      gsPos.addresses = addresses;

      gsPos.doInBackground( );

      gsSendPos.addresses = addresses;

      gsSendPos.positions = gsPos.positions;

      gsSendPos.doInBackground( );

      start = false;

    }

    else

    {

      addresses = gsID.addresses;

      gsPos.addresses = addresses;

      gsSendPos.addresses = addresses;

      gsSendPos.positions = gsPos.positions;

    }

  }

但它仍然再次卡在 gameServerID 接收方法上。

我只是将我的所有类都更改为线程,它工作得更好,但在更高版本的 android 4.0 中,线程不能从 UI 使用,但我不确定如何从非 UI 启动它们?


来自 DatagramSocket.receive 的 Javadoc:

This method blocks until a datagram is received

所以您的代码"卡住"了,因为它正在等待数据包到达。这意味着连接到此服务器/端口的客户端尚未发送另一个数据包,因此套接字被设计为阻塞。

传统上,如果您想同时监听多个端口,您有两种选择:

  • 在不同的线程上打开每个阻塞套接字(如果由于每个线程一个客户端而同时有大量客户端,这将无法很好地扩展,但对于少量连接可以正常工作)
  • 使用 NIO,它是 Java 的非阻塞 IO

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