How is a report generated in your project when a user button is pressed?

In my project, the report is generated when the user clicks a button as follows:

1. The button click handler calls a service method that gathers the necessary data.
2. The data is formatted into the required report format (e.g., PDF or Excel) using a library such as Apache POI for Excel or iText for PDF.
3. The generated report is saved on the server or sent to the user for download.

Example of a button handler code in Java using Spring MVC:

@PostMapping("/generateReport")
public ResponseEntity<byte[]> generateReport() {
    byte[] reportData = reportService.createReport();
    HttpHeaders headers = new HttpHeaders();
    headers.setContentType(MediaType.APPLICATION_PDF);
    headers.setContentDispositionFormData("attachment", "report.pdf");
    return new ResponseEntity<>(reportData, headers, HttpStatus.OK);
}

Thus, when the button is clicked, the user receives the generated report.