UDP

接收端：

public class UDPServer
{

	public static void main(String[] args) throws IOException
	{
		DatagramSocket udp = new DatagramSocket(9999);
		byte[] b = new byte[udp.getSendBufferSize()];
		
		DatagramPacket pack = new DatagramPacket(b, b.length);
		udp.receive(pack);
		System.out.println(pack.getLength());
		System.out.println(pack.getAddress().getHostAddress());
		System.out.println(new String(pack.getData()).trim());
		udp.close();
	}
}

发送端：

public class UDPClient
{

	public static void main(String[] args) throws IOException
	{
		DatagramSocket udp = new DatagramSocket(8888);
		byte[] b = "myname".getBytes();
		DatagramPacket pack = new DatagramPacket(b, b.length);

		InetSocketAddress address = new InetSocketAddress("127.0.0.1", 9999);
		pack.setSocketAddress(address);
		udp.send(pack);
		udp.close();
	}
}