How to read and write excel file

There are several ways to read and write Excel files in Java. Here are a few options:

  1. Apache POI: This is a popular library for reading and writing Microsoft Office file formats, including Excel files. You can find more information and download the library at https://poi.apache.org/.

  2. JExcelAPI: This is another library that allows you to read and write Excel files in Java. You can find more information and download the library at https://sourceforge.net/projects/jexcelapi/.

  3. Google Sheets API: If you want to read and write Excel files stored in Google Sheets, you can use the Google Sheets API. You can find more information and documentation for the API at https://developers.google.com/sheets/.

To use any of these libraries, you will need to add the library to your project and import the necessary classes. Then you can use the APIs provided by the library to read and write Excel files.

For example, using Apache POI, you can read an Excel file like this:

import org.apache.poi.ss.usermodel.*;
import java.io.FileInputStream;

// Open the Excel file
FileInputStream file = new FileInputStream("file.xlsx");

// Get the workbook instance for XLSX file
Workbook workbook = WorkbookFactory.create(file);

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

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

    // For each row, iterate through each columns
    Iterator<Cell> cellIterator = row.cellIterator();
    while (cellIterator.hasNext()) {
        Cell cell = cellIterator.next();

        switch (cell.getCellType()) {
            case Cell.CELL_TYPE_BOOLEAN:
                System.out.print(cell.getBooleanCellValue() + "\t\t");
                break;
            case Cell.CELL_TYPE_NUMERIC:
                System.out.print(cell.getNumericCellValue() + "\t\t");
                break;
            case Cell.CELL_TYPE_STRING:
                System.out.print(cell.getStringCellValue() + "\t\t");
                break;
        }
    }
    System.out.println("");
}

file.close();

To write to an Excel file, you can use similar code, but instead of reading cell values, you can set cell values and then write the workbook to a file.

I hope this helps! Let me know if you have any questions.