工具方法：
public static <T> T parseJsonString(String json,Class<T> classType){
        ObjectMapper mapper = new ObjectMapper();
        T object = null;
        try {
            object = mapper.readValue(json,classType);
        } catch (JsonParseException e) {
            logger.error("json解析异常",e);
        } catch (JsonMappingException e) {
            logger.error("json解析异常",e);
        } catch (IOException e) {
            logger.error("文件读取异常",e);
        }
        return object;
    }