【发布时间】:2020-12-23 04:57:29
【问题描述】:
我遇到的问题是,当我打开第二个客户端时,服务器似乎没有检测到第二个客户端已打开。第一次打开客户端时,它工作正常,服务器检测到客户端已连接。
服务器:
public class Server {
Socket previousSocket = null;
private static int port = 9001;
public static void main(String[] args) throws Exception {
ServerSocket serverSocket = new ServerSocket(port);
System.out.println("[SERVER] Server successfully launched on port: " + port);
DatagramSocket UDPSocket = new DatagramSocket(9002);
Socket previousSocket = null;
while (true) {
Socket newSocket = serverSocket.accept();
System.out.println("new client connected");
if (previousSocket == null) {
previousSocket = newSocket;
System.out.println("1 st client");
} else {
System.out.println("2 nd client");
previousSocket = null;
}
byte[] data = new byte[500];
DatagramPacket received = new DatagramPacket(data, data.length);
while(true) {
UDPSocket.receive(received);
String receivedData = new String(received.getData());
System.out.println(receivedData);
}
}
}
}
客户:
public ChatClient() throws UnknownHostException, IOException {
Socket socket = new Socket("127.0.0.1", 9001);
Scanner scanner = new Scanner(System.in);
DatagramSocket UDPSocket = new DatagramSocket();
while(scanner.hasNextLine()) {
String message = scanner.nextLine();
InetAddress ip = InetAddress.getByName("127.0.0.1");
DatagramPacket packet = new DatagramPacket(message.getBytes(), message.getBytes().length, ip, 9002);
UDPSocket.send(packet);
}
}
【问题讨论】:
-
调用
UDPSocket.receive(received);的内部while(true)永远不会退出,因此外部循环中的serverSocket.accept();只调用一次。虽然您显然只使用端口 9002 发送和接收数据,但为什么首先在端口 9001 上有一个 ServerSocket?
标签: java tcp udp client-server