FormToExcelApp.java

import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

public class FormToExcelApp {
    public static void main(String[] args) {
        SwingUtilities.invokeLater(FormToExcelApp::createAndShowGUI);
    }

    private static void createAndShowGUI() {
        JFrame frame = new JFrame("Form to Excel");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(400, 300);
        frame.setLayout(new GridLayout(4, 2));

        JLabel nameLabel = new JLabel("Name:");
        JTextField nameField = new JTextField();

        JLabel emailLabel = new JLabel("Email:");
        JTextField emailField = new JTextField();

        JButton submitButton = new JButton("Submit");

        frame.add(nameLabel);
        frame.add(nameField);
        frame.add(emailLabel);
        frame.add(emailField);
        frame.add(submitButton);

        submitButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                String name = nameField.getText();
                String email = emailField.getText();
                if (!name.isEmpty() && !email.isEmpty()) {
                    saveToExcel(name, email);
                    JOptionPane.showMessageDialog(frame, "Data saved to Excel");
                } else {
                    JOptionPane.showMessageDialog(frame, "Please fill all fields", "Warning", JOptionPane.WARNING_MESSAGE);
                }
            }
        });

        frame.setVisible(true);
    }

    private static void saveToExcel(String name, String email) {
        String filePath = "FormData.xlsx";
        File file = new File(filePath);
        Workbook workbook;
        Sheet sheet;

        try {
            if (file.exists()) {
                workbook = WorkbookFactory.create(file);
                sheet = workbook.getSheetAt(0);
            } else {
                workbook = new XSSFWorkbook();
                sheet = workbook.createSheet("Form Data");
                Row headerRow = sheet.createRow(0);
                headerRow.createCell(0).setCellValue("Name");
                headerRow.createCell(1).setCellValue("Email");
            }

            int rowCount = sheet.getLastRowNum() + 1;
            Row row = sheet.createRow(rowCount);
            row.createCell(0).setCellValue(name);
            row.createCell(1).setCellValue(email);

            try (FileOutputStream fileOut = new FileOutputStream(filePath)) {
                workbook.write(fileOut);
            }
            workbook.close();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }
}