private static ExcelContentProperty doGetExcelContentProperty(Class<?> clazz, Class<?> headClass,
        String fieldName,
        ConfigurationHolder configurationHolder) {
        ExcelContentProperty excelContentProperty = Optional.ofNullable(
                declaredFieldContentMap(clazz, configurationHolder))
            .map(map -> map.get(fieldName))
            .orElse(null);
        ExcelContentProperty headExcelContentProperty = Optional.ofNullable(
                declaredFieldContentMap(headClass, configurationHolder))
            .map(map -> map.get(fieldName))
            .orElse(null);
        ExcelContentProperty combineExcelContentProperty = new ExcelContentProperty();

        combineExcelContentProperty(combineExcelContentProperty, headExcelContentProperty);
        if (clazz != headClass) {
            combineExcelContentProperty(combineExcelContentProperty, excelContentProperty);
        }
        return combineExcelContentProperty;
    }
Calculate the configuration information for the class

@param dataMap
@param headClazz
@param fieldName
@return
fastexcel-core/src/main/java/cn/idev/excel/util/ClassUtils.java