public static String getJsonFromData(Data data){
		ObjectMapper mapper = new ObjectMapper();

		StringWriter writer = new StringWriter() ;
		try {
			mapper.writeValue(writer, data) ;
		} catch (JsonGenerationException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (JsonMappingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return writer.toString() ;
	}