用UDP实现简单的聊天功能_udp 聊天上线提醒功能-优快云博客

本文介绍了一个使用Java实现的基于UDP协议的简单聊天室系统，包括客户端发送消息和服务器接收并广播消息的功能。通过创建线程处理并发连接，实现了基本的聊天功能。

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package com.hbsi.net;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;

public class Chat{
public static void main(String[] args) {
Send s=new Send();
Receive r=new Receive();
Thread ts=new Thread(s);
Thread tr=new Thread(r);
ts.start();
tr.start();
}
}

//发送
class Send implements Runnable{
@Override
public void run() {
// TODO Auto-generated method stub

DatagramSocket ds;
BufferedReader br;
try {
ds = new DatagramSocket();

br=new BufferedReader(new InputStreamReader(System.in));

String line=null;
String line2=InetAddress.getLocalHost().toString();
while((line=br.readLine())!=null){
System.out.print(line2+"\n　　　　");
if(line.equals("886")){
break;
}
byte[] buf=line.getBytes();
DatagramPacket dp=new DatagramPacket(buf, buf.length, InetAddress.getByName("192.168.49.255【接受信息人的IP】"),9009);
ds.send(dp);
}
ds.close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}

//接收
class Receive implements Runnable{

public void run() {
while(true){
DatagramSocket ds;
try {
ds = new DatagramSocket(9009);
while(true){
byte[] buf=new byte[1024];
DatagramPacket dp=new DatagramPacket(buf, buf.length);

ds.receive(dp);

String ip=dp.getAddress().getHostAddress();
String data=new String(dp.getData()).trim();

System.out.println("\n"+ip+"--"+data);
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

}