关于 java: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

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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();
}
}

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

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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

原创文章，作者：ItWorker，如若转载，请注明出处：https://blog.ytso.com/tech/java/267519.html

关于 java:doInBackground 卡住

doInBackground gets stuck

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