How to protect Excel file with password in Java

package testexceljava;

import EasyXLS.*;

/* -----------------------------------------------------------------------------
 | Tutorial 27
 |
 | This tutorial shows how to create an Excel file in Java and
 | encrypt the Excel file by setting the password required for opening the file.
 * ----------------------------------------------------------------------------- */

public class Tutorial27 {

    public static void main(String[] args) {
        try {
            System.out.println("Tutorial 27");
            System.out.println("----------");

            // Create an instance of the class that exports Excel files, having two sheets
            ExcelDocument workbook = new ExcelDocument(2);
            
            // Set the sheet names
            workbook.easy_getSheetAt(0).setSheetName("First tab");
            workbook.easy_getSheetAt(1).setSheetName("Second tab");
            
            // Set the password for protecting the Excel file when the file is open
            workbook.easy_getOptions().setPasswordToOpen("password");
            
            // Export Excel file
            System.out.println(
                "Writing file: C:\\Samples\\Tutorial27 - protect Excel with password and encryption.xlsx");
            workbook.easy_WriteXLSXFile(
                "C:\\Samples\\Tutorial27 - protect Excel with password and encryption.xlsx");

            // Confirm export of Excel file
            if (workbook.easy_getError().equals(""))
                System.out.println("File successfully created.");
            else
                System.out.println("Error encountered: " + workbook.easy_getError());

            // Dispose memory
            workbook.Dispose();
        }
        catch (Exception ex) {
            ex.printStackTrace();
        }
    }
}