public class SendMessageDemo {public static void main(String[] args) throws IOException {//发送数据//创建Datagramsocket对象（快递公司）//细节：//绑定端口，以后我们就是通过这个端口往外发送//空参：所有可用的端口随机一个进行使用//有参：指定端口号进行绑定DatagramSocket  ds=new DatagramSocket();//打包数据String str="你好威啊！！";byte[] bytes=str.getBytes();InetAddress address= InetAddress.getByName("127.0.0.1");int port=10086;DatagramPacket dp=new DatagramPacket(bytes,bytes.length,address,port);//发送数据ds.send(dp);//释放资源ds.close();}
}

public class ReceviceMessageDemo {public static void main(String[] args) throws IOException {//接收数据//创建DatagramSocket对象//接收的时候，一定要绑定端口，而且绑定的端口和发送的端口保持一致DatagramSocket ds=new DatagramSocket(10086);//接收数据包byte[]bytes=new byte[1024];DatagramPacket dp=new DatagramPacket(bytes,bytes.length);ds.receive(dp);//解析数据包byte[] data = dp.getData();int length = dp.getLength();InetAddress address = dp.getAddress();int port = dp.getPort();System.out.println("接收到数据："+new String(data,0,length));System.out.println("该数据是从"+address+"这台电脑中的端口"+port+"发送出来的");}
}