public static String deCoder(String str){
		BASE64Decoder decoder = new BASE64Decoder();
		String okcoder = "";	//okcoderʼΪ""ұ⡣
		try {
			okcoder = new String(decoder.decodeBuffer(str));
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return okcoder;
	}