Read files of .csv, .xlsx and .xls in Groovy

Needed jars:

poi-3.7.jar
poi-ooxml-3.6-20100309.jar
poi-ooxml-schemas-3.6-20100309.jar
xmlbeans-2.3.0.jar


/** * To read the uploaded csv file line by line * @param fileName : "fileName" as request.getFile('param name') * @return list */def readFile(fileName) {
    def list = []
    fileName.inputStream.splitEachLine(','){
        list << it
    }
    if (list.size() > 0) {
        return list
    } else {
        /*TODO add message : file is empty*/        return    }
}

/** * Convert .xlsx file data to array * @param file as request.getFile('file as param name') * @return */def convertXlsxFileToArray(file) {
    def array = []
    if(!file.empty) {
        XSSFWorkbook book = new XSSFWorkbook(file.getInputStream());
        XSSFSheet[] sheets = book.sheets;
        for (XSSFSheet sheet : sheets) {
            sheet.each{row->
                Iterator cellIterator = row.cellIterator()
                def record = []
                while(cellIterator.hasNext())
                {
                    XSSFCell cell = cellIterator.next()
                    record.add(cell)
                }
                array.add(record)
            }
        }
    }
    return array
}

/** * Convert .xlsx file data to array * @param file as request.getFile('file as param name') * @return */def convertXlsFileToArray(file) {
    def array = []
    HSSFWorkbook workbook = new HSSFWorkbook(file.getInputStream());
    HSSFSheet sheet = workbook.getSheetAt(0);
    sheet.each{row->
        Iterator cellIterator = row.iterator()
        def record = []
        while(cellIterator.hasNext())
        {
            HSSFCell cell = cellIterator.next()
            record.add(cell)
        }
        array.add(record)
    }
    return array
}