udp实现多线程通信

此处以老师与学生聊天通信举例

消息发送（客户端）

package udp.chat;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;

public class TalkSend implements Runnable{
DatagramSocket socket=null;
BufferedReader reader=null;

private int fromPort;
private String toIp;
private int toPort;
public TalkSend(int fromPort, String toIp, int toPort) {
	this.fromPort=fromPort;
	this.toIp=toIp;
	this.toPort=toPort;
	try {
	socket= new DatagramSocket(fromPort);
	reader=new BufferedReader(new InputStreamReader(System.in));
	} catch (Exception e) {
		// TODO: handle exception
	}
}

@Override
public void run() {
	//准备数据：控制读取 system.in
	while(true) {
		try {
			String data=reader.readLine();
			byte[]  datas=data.getBytes();  
			DatagramPacket packet=new DatagramPacket(datas, 0, datas.length,new InetSocketAddress(this.toIp, this.toPort));
			socket.send(packet);
			if (data.equals("bye")) {
				break;
			}
		} catch (Exception e) {
			e.printStackTrace();
			
		}
}
	 socket.close();
	
	
}

}

消息接收（服务端）

package udp.chat;

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;

public class TalkReceive implements Runnable{
DatagramSocket socket=null;
private int port;
private String msgFrom;
public TalkReceive(int port, String msgFrom) {
this.port=port;
this.msgFrom=msgFrom;
try {
socket=new DatagramSocket(port);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
@Override
public void run() {

	while (true) {
		try {
			//准备接受包裹
			byte[] container=new byte[1024];
			DatagramPacket packet=new  DatagramPacket(container, 0,container.length);
			socket.receive(packet);
			//断开连接
			byte[] data=packet.getData();
			String receiveData= new String(data,0,data.length);
			System.out.println(msgFrom+""+receiveData);
			if (receiveData.equals("bye")) {
				break;
			}
			
		} catch (Exception e) {
			// TODO: handle exception
		}
		
	}
	socket.close();
			
}

}

创建消息发送接收实例

package udp.chat;
public class TalkStudent {
public static void main(String[] args) {
//开启两个线程
new Thread(new TalkSend(5555,“localhost”,8888)).start();
new Thread(new TalkReceive(9999,“学生：”)).start();
}
}

package udp.chat;
public class TalkTeacher {
public static void main(String[] args) {
//开启两个线程
new Thread(new TalkSend(7777,“localhost”,9999)).start();
new Thread(new TalkReceive(8888,“老师：”)).start();
}

}