異常：java.net.BindException：不能分配請求的地址

Question

我想發送和接收數據報套接字，但我收到異常java.net.BindException: Cannot assign requested address。我通過了我想要通信的正確的服務器ipaddress並修正了端口號。

try { 
    SocketAddress sockaddr = new InetSocketAddress("203.100.77.54", 8000); 
    DatagramSocket sock = new DatagramSocket(sockaddr); 
    DatagramPacket pack = new DatagramPacket(bData, bData.length); 
    sock.send(pack); 
} catch (FileNotFoundException fnfe) { 
    Log.e(LOG_TAG, "FileNotFoundException"); 
} catch (SocketException se) { 
    Log.e(LOG_TAG, "SocketException"); 
} catch (UnknownHostException uhe) { 
    Log.e(LOG_TAG, "UnknownHostException"); 
} catch (IOException ie) { 
    Log.e(LOG_TAG, "IOException"); 
} 

請幫幫我。

Answer 1

嘗試這樣

String messageStr = "Hello Android!"; 
int server_port = 8000; 
DatagramSocket s = new DatagramSocket(); 
InetAddress local = InetAddress.getByName("203.100.77.54"); 
int msg_length = messageStr.length(); 
byte[] message = messageStr.getBytes(); 
DatagramPacket p = new DatagramPacket(message, msg_length, local, server_port); 
s.send(p); 

Answer 2

DatagramSockets不與目標地址創建。它們使用它們自己的本地綁定地址（或無）創建，這會在首次使用時導致默認綁定。目標地址在構造DatagramPacket時指定，或者在connect（）方法中指定。