Java UDP

public static String faceDetect(String itemStr) throws IOException {
    	String sRt;
        DatagramSocket client = new DatagramSocket();
        byte[] sendBuf = itemStr.getBytes("GB2312");
        InetAddress addr = InetAddress.getByName("127.0.0.1");
        int port = 5500;
        DatagramPacket sendPacket = new DatagramPacket(sendBuf ,sendBuf.length , addr , port);
        client.send(sendPacket);
        byte[] recvBuf = new byte[100];
        String recvStr = null;
        DatagramPacket recvPacket= new DatagramPacket(recvBuf , recvBuf.length);
        while(true){
        	client.setSoTimeout(60000);
        	try{
        		client.receive(recvPacket);
	    		recvStr = new String(recvPacket.getData() , 0 ,recvPacket.getLength(),"gb2312").trim();
	            if (recvStr!=null && recvStr.length()>0) {
	            	sRt = recvStr;
	            	break;
	 		}
        	}catch(SocketTimeoutException e){
        		LOGGER.error("UDP线路故障，请确认UDP客户端是否开启");
        		sRt="9999";
			break;
        	}
        }
        client.close();
        return sRt;
    }