1
我寫了兩個程序。現在每個程序都使用線程來同時發送和接收數據包。 每當我將數據包從服務器發送到客戶端時，客戶端的消息都會以無限循環接收。即;我已經添加了一條打印語句，用於打印發送的消息，並且在無限循環中永遠消失。我想讓它接收消息，然後能夠回寫到服務器並在用戶需要時退出。Java中的UDP線程無限循環
我試過使用socket.close（），但這使得客戶端收到消息，我只能寫回服務器一次。我發送後，我不能再發送了。我想讓它可以多次寫回。
任何人都可以請指出我在正確的方向嗎？
我的代碼如下;
public class UDPThreadClient extends Thread {
public static int port1;
//Create threaded server
UDPThreadClient (int port1) {
System.out.println ("Starting threaded client");
start();
}
public void run() {
int port = port1;
try {
DatagramSocket serverSocket = new DatagramSocket(port1);
byte[] receiveData = new byte[1024];
byte[] sendData = new byte[1024];
while (true) {
DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
serverSocket.receive(receivePacket);
String sentence = new String(receivePacket.getData());
SocketAddress address = receivePacket.getSocketAddress();
System.out.println("RECEIVED from " + address + " : " + sentence);
InetAddress IPAddress = receivePacket.getAddress();
//int port = receivePacket.getPort();
String capitalizedSentence = sentence.toUpperCase();
sendData = capitalizedSentence.getBytes();
DatagramPacket sendPacket =
new DatagramPacket(sendData, sendData.length, IPAddress, port);
serverSocket.send(sendPacket);
//serverSocket.close();
}
} catch (IOException e) {
System.out.println (e.getMessage());
}
}
//Create client
public static void main(String[] args) {
int port = Integer.parseInt(args[0]);
port1 = Integer.parseInt(args[1]);
new UDPThreadClient (port1);
try {
BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));
DatagramSocket clientSocket = new DatagramSocket();
InetAddress IPAddress = InetAddress.getByName("localhost");
byte[] sendData = new byte[1024];
byte[] receiveData = new byte[1024];
String sentence = inFromUser.readLine();
sendData = sentence.getBytes();
DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, IPAddress, port);
clientSocket.send(sendPacket);
DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
clientSocket.receive(receivePacket);
String modifiedSentence = new String(receivePacket.getData());
System.out.println("FROM SERVER:" + modifiedSentence);
//clientSocket.close();
} catch (IOException e) {
System.out.println (e.getMessage());
}
}
}
和
public class UDPThreadServer extends Thread {
public static int port1;
//Create threaded client
UDPThreadServer() {
System.out.println ("Starting threaded server");
start();
}
public void run() {
try {
DatagramSocket clientSocket = new DatagramSocket();
BufferedReader inFromUser = new BufferedReader (new InputStreamReader(System.in));
Scanner in = new Scanner (inFromUser);
InetAddress IPAddress = InetAddress.getByName("localhost");
byte[] sendData = new byte [1024];
byte[] receiveData = new byte [1024];
while (in.hasNextLine()) {
String sentence = in.nextLine();
//inFromUser.readLine();
sendData = sentence.getBytes();
DatagramPacket sendPacket = new DatagramPacket (sendData, sendData.length, IPAddress, port1);
clientSocket.send(sendPacket);
DatagramPacket receivePacket = new DatagramPacket (receiveData, receiveData.length);
clientSocket.receive (receivePacket);
String modSentence = new String (receivePacket.getData());
System.out.println ("FROM SERVER: " + modSentence);
}
//clientSocket.close();
} catch (IOException e) {
System.out.println (e.getMessage());
}
}
//Create server
public static void main(String[] args) {
int port = Integer.parseInt(args[0]);
port1 = Integer.parseInt(args[1]);
new UDPThreadServer();
try {
DatagramSocket serverSocket = new DatagramSocket (port);
byte[] receiveData = new byte[1024];
byte[] sendData = new byte[1024];
while (true) {
DatagramPacket receivePacket = new DatagramPacket (receiveData, receiveData.length);
serverSocket.receive(receivePacket);
String sentence = new String(receivePacket.getData());
SocketAddress address = receivePacket.getSocketAddress();
System.out.println ("Received from " + address + " : " + sentence);
InetAddress IPAddress = receivePacket.getAddress();
String capSentence = sentence.toUpperCase();
sendData = capSentence.getBytes();
DatagramPacket sendPacket = new DatagramPacket (sendData, sendData.length, IPAddress, port);
serverSocket.send(sendPacket);
//serverSocket.close();
}
} catch (IOException e) {
System.out.println (e.getMessage());
}
}
}
感謝。
感謝Atreys，當我嘗試打印getPort（）的值時，我得到-1。當我真的刪除while（true）時，while循環停止。但是，我仍然無法發送多次。我明白你的意思，而我現在只是有點困惑，因爲沒有while循環，一切似乎都能正常工作，只是我無法發送一次以上的事實。 – Triple777er 2011-05-31 11:36:50
@ Triple777er，我編輯了我的答案，並對UDPThreadServer進行了修改，使其與主要方法一起工作。 – Atreys 2011-05-31 14:28:39
非常感謝Atreys，這幫助我解決了我的問題。感謝您花時間幫助我。非常感激。 – Triple777er 2011-06-01 05:27:28