Excel to HTML Converter with Automatic Column Width Adjustment

import java.awt.; import java.io.; import java.text.SimpleDateFormat; import java.util.Date; import java.util.Iterator;

import org.apache.poi.ss.usermodel.; import org.apache.poi.xssf.usermodel.; import org.apache.poi.hssf.usermodel.; import org.apache.poi.ss.util.; import org.apache.poi.hssf.util.*; import org.apache.poi.ss.usermodel.Row.MissingCellPolicy;

public class ExcelToHtmlConverter { public static void main(String[] args) throws Exception { String excelFilePath = 'input.xlsx'; File inputFile = new File(excelFilePath);

    //Get the workbook instance for XLSX file
    Workbook workbook = null;
    if (excelFilePath.endsWith('xlsx')) {
        workbook = new XSSFWorkbook(new FileInputStream(inputFile));
    } else if (excelFilePath.endsWith('xls')) {
        workbook = new HSSFWorkbook(new FileInputStream(inputFile));
    }

    //Get the first sheet from the workbook
    Sheet sheet = workbook.getSheetAt(0);

    //Create a new HTML table
    StringBuffer htmlTable = new StringBuffer('<table style="border-collapse: collapse;">');

    //Get the maximum number of columns used by any row in the sheet
    int maxColumns = 0;
    Iterator<Row> rowIterator = sheet.iterator();
    while (rowIterator.hasNext()) {
        Row row = rowIterator.next();
        int lastCellNum = row.getLastCellNum();
        if (lastCellNum > maxColumns) {
            maxColumns = lastCellNum;
        }
    }

    //Calculate the width of each column based on the maximum number of characters in any cell of that column
    int[] columnWidths = new int[maxColumns];
    rowIterator = sheet.iterator();
    while (rowIterator.hasNext()) {
        Row row = rowIterator.next();
        Iterator<Cell> cellIterator = row.cellIterator();
        int columnNum = 0;
        while (cellIterator.hasNext()) {
            Cell cell = cellIterator.next();
            String cellValue = '';
            switch (cell.getCellType()) {
                case STRING:
                    cellValue = cell.getStringCellValue();
                    break;
                case NUMERIC:
                    if (DateUtil.isCellDateFormatted(cell)) {
                        Date date = cell.getDateCellValue();
                        SimpleDateFormat sdf = new SimpleDateFormat('yyyy-MM-dd HH:mm:ss');
                        cellValue = sdf.format(date);
                    } else {
                        cellValue = String.valueOf(cell.getNumericCellValue());
                    }
                    break;
                case BOOLEAN:
                    cellValue = String.valueOf(cell.getBooleanCellValue());
                    break;
                case FORMULA:
                    cellValue = cell.getCellFormula();
                    break;
                case BLANK:
                    cellValue = '';
                    break;
                default:
                    cellValue = cell.toString();
            }
            int cellLength = cellValue.length();
            if (cellLength > columnWidths[columnNum]) {
                columnWidths[columnNum] = cellLength;
            }
            columnNum++;
        }
    }

    //Iterate through each rows from first sheet
    rowIterator = sheet.iterator();
    while (rowIterator.hasNext()) {
        Row row = rowIterator.next();

        //Create a new HTML table row
        htmlTable.append('<tr>');

        //Iterate through each columns from the row
        Iterator<Cell> cellIterator = row.cellIterator();
        int columnNum = 0;
        while (cellIterator.hasNext()) {
            Cell cell = cellIterator.next();

            //Create a new HTML table cell
            htmlTable.append('<td style="border: 1px solid #ddd; padding: 8px;');

            //Set the width of the cell based on the width of the column
            int columnWidth = columnWidths[columnNum] * 10;
            htmlTable.append('width: ' + columnWidth + 'px;');

            //Close the HTML table cell opening tag
            htmlTable.append('">');

            //Get the cell value and append to HTML table cell
            switch (cell.getCellType()) {
                case STRING:
                    htmlTable.append(cell.getStringCellValue());
                    break;
                case NUMERIC:
                    if (DateUtil.isCellDateFormatted(cell)) {
                        Date date = cell.getDateCellValue();
                        SimpleDateFormat sdf = new SimpleDateFormat('yyyy-MM-dd HH:mm:ss');
                        String formattedDate = sdf.format(date);
                        htmlTable.append(formattedDate);
                    } else {
                        htmlTable.append(cell.getNumericCellValue());
                    }
                    break;
                case BOOLEAN:
                    htmlTable.append(cell.getBooleanCellValue());
                    break;
                case FORMULA:
                    htmlTable.append(cell.getCellFormula());
                    break;
                case BLANK:
                    htmlTable.append('');
                    break;
                default:
                    htmlTable.append(cell);
            }

            //Close the HTML table cell
            htmlTable.append('</td>');
            columnNum++;
        }

        //Close the HTML table row
        htmlTable.append('</tr>');
    }

    //Close the HTML table
    htmlTable.append('</table>');

    //Close the workbook
    workbook.close();

    //Create a new HTML file and write the table content
    String htmlFilePath = 'output.html';
    File htmlFile = new File(htmlFilePath);
    BufferedWriter writer = new BufferedWriter(new FileWriter(htmlFile));
    writer.write(htmlTable.toString());
    writer.close();

    //Open the HTML file in default browser
    Desktop.getDesktop().browse(htmlFile.toURI());
}

}