套接字接收設置超時

Question

我想發送數據到服務器，然後等待一分鐘的答案，然後關閉套接字。

怎麼辦？

DatagramPacket sendpack = new ......; 
socket.send(pack); 
DatagramPacket recievepack = new .....; 
//wait 1 minute{ 
socket.recieve(buf); 
//wait 1 minute} 
socket.close(); 

Answer 1

您可以試試這個。按照您的方案中的要求更改套接字的超時值！此代碼將發送一條消息，然後等待接收消息，直到達到超時！

DatagramSocket s; 

    try { 
     s = new DatagramSocket(); 
     byte[] buf = new byte[1000]; 
     DatagramPacket dp = new DatagramPacket(buf, buf.length); 
     InetAddress hostAddress = InetAddress.getByName("localhost"); 

     String outString = "Say hi";  // message to send 
     buf = outString.getBytes(); 

     DatagramPacket out = new DatagramPacket(buf, buf.length, hostAddress, 9999); 
     s.send(out);  // send to the server 

     s.setSoTimeout(1000); // set the timeout in millisecounds. 

     while(true){  // recieve data until timeout 
      try { 
       s.receive(dp); 
       String rcvd = "rcvd from " + dp.getAddress() + ", " + dp.getPort() + ": "+ new String(dp.getData(), 0, dp.getLength()); 
       System.out.println(rcvd); 
      } 
      catch (SocketTimeoutException e) { 
       // timeout exception. 
       System.out.println("Timeout reached!!! " + e); 
       s.close(); 
      } 
     } 

    } catch (SocketException e1) { 
     // TODO Auto-generated catch block 
     //e1.printStackTrace(); 
     System.out.println("Socket closed " + e1); 

    } catch (IOException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 

Answer 2

如果使用DatagramSocket，或Socket可以使用，

socket.setSoTimeout(1000); 
//the value is in milliseconds 

對於任何一個細節，你應該已經邁出DatagramSocket javadoc或Socket javadoc看看。

Answer 3

爲了澄清EJP的評論，這是他的意思是「丟失break」導致一個SocketException。

String group = "224.0.0.0"; 
int port = 5000; 

MulticastSocket recvSock = new MulticastSocket(port); 
recvSock.joinGroup(InetAddress.getByName(group)); 
recvSock.setSoTimeout(1000); 

while(true) { 
    try { 
     recvSock.receive(in);    
    } catch (SocketTimeoutException e) { 
     break; // Closing here would cause a SocketException 
    } 
} 

// Move the close() outside the try catch bloock 
recvSock.leaveGroup(InetAddress.getByName(group)); 
recvSock.close();