客户A
import java.io.*;
import java.net.*;
import java.util.*;
public class ClientA
{
final private static int PORT = 5005; // arbitrarily assigned port to use
public static void main(String args[]) throws
IOException
{
DatagramSocket socket = new DatagramSocket(PORT); // create new connection on that port
while (true)
{
byte buffer[] = new byte[256]; // data buffer
DatagramPacket packet = new DatagramPacket(buffer, buffer.length); // new packet containing buffer
socket.receive(packet); // look for packet
String clientBMsg = new String(packet.getData()); // get data from received packet
InetAddress address = packet.getAddress(); // get address of received packet
System.out.println("ClientB at " + address + " says " + clientBMsg);
buffer = null;
String msgString = "I'm ClientA, vegetables are fun";
buffer = msgString.getBytes(); // put String in buffer
int port = packet.getPort(); // get port of received packet
packet = new DatagramPacket(buffer, buffer.length, address, port); // create new packet with this data
socket.send(packet); // send packet back containing new buffer!
System.out.println("Message Sent");
socket.close();
}
}
}
客户乙
import java.io.*;
import java.net.*;
public class ClientB
{
final private static int PORT = 5005; // arbitrarily assigned port - same as server
public static void main(String args[]) throws
IOException {
// if (args.length == 0) { // requires host
// System.err.println
// ("Please specify host");
// System.exit(-1);
// }
// String host = args[0]; // user defined host
DatagramSocket socket = new DatagramSocket(); // open new socket
String host = "localhost";//"86.0.164.207";
byte message[] = new byte[256]; // empty message
String msgString = "Hello, I'm client B and I like trees";
message = msgString.getBytes(); // put String in buffer
InetAddress address = InetAddress.getByName(host); // determines address
System.out.println("Sending to: " + address); // tells user it's doing something
DatagramPacket packet = new DatagramPacket(message, message.length, address, PORT); // create packet to send
socket.send(packet); // send packet
System.out.println("Message Sent");
message = new byte[256];
packet = new DatagramPacket(message, message.length);
socket.receive(packet); // wait for response
String clientAreply = new String(packet.getData());
System.out.println("ClientA at " + host + " says " + clientAreply);
socket.close();
}
}
我不明白为什么这会在 localhost 上工作,但是当我输入 IP 地址时,它只是发送消息而没有收到任何消息。
任何人都可以指出我正确的方向吗?
谢谢!
最佳答案
您应该使用 DatagramSocket
的 bind
方法将其绑定(bind)到您的互联网接口(interface),否则它只会监听 127.0.0.1
或 localhost
。像这样:
DatagramSocket socket = new DatagramSocket(null);
socket.bind(new InetSocketAddress(InetAddress.getByName("your.ip.add.ress"),5005);
如果您在路由器后面,那么您应该监听路由器提供给您的本地 IP 地址,并在路由器设置中使用端口转发到该地址。
关于Java UDP 消息交换在本地主机上工作而不是在互联网上工作?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/9709956/