java DategramSocker发送消息和接收消息

DatagramSocket datagramSocket = new DatagramSocket();
			byte[] Mybytre = content.getBytes();
			//第一参数是要发送的字节，第二个参数是发送的长度,第三个参数是对方的IP，第四个参数是对方的端口号
			DatagramPacket datagramPacket = new DatagramPacket(Mybytre,Mybytre.length, InetAddress.getByName(ip), 10008);
			datagramSocket.send(datagramPacket);
			datagramSocket.close();

info = new DatagramSocket(10008,InetAddress.getByName(AppEntity.getLocalIpAddress()));
				while (true) {
					byte[] b = new byte[2040];
					DatagramPacket packer = new DatagramPacket(b, b.length);
					info.receive(packer);
					String con = new String(packer.getData(), 0,packer.getLength(), "UTF-8");//接收到的消息
					hostIp = packer.getAddress().getHostAddress(); // 获取对方的IP
					Log.d("nnn", "IP是" + hostIp + ":内容是" + con);