@Override
    public Long convertToJavaData(ReadCellData<?> cellData, ExcelContentProperty contentProperty,
                                  GlobalConfiguration globalConfiguration) {
        return cellData.getNumberValue().longValue();
    }
Long and number converter

@author Jiaju Zhuang
fastexcel-core/src/main/java/cn/idev/excel/converters/longconverter/LongNumberConverter.java