Export data from database to xlsx file (Excel) using spring - excel

Question

I need to export data from database to excel document using spring.
But when I download from controller document I get message that is currupted file or wrong extension.
private static final String EXCEL_FILE_NAME = "UserExcelExport.xlsx";
#GetMapping("/download")
public void download(HttpServletResponse response) throws Exception {
List<User> users = userService.getUsers();
Workbook workbook = new HSSFWorkbook();
Sheet sheet = workbook.createSheet("All Users List");
Row header = sheet.createRow(0);
header.createCell(0).setCellValue("Username");
header.createCell(1).setCellValue("First name");
header.createCell(2).setCellValue("Last name");
header.createCell(3).setCellValue("E-mail");
int rowNum = 1;
for (User user : users) {
Row row = sheet.createRow(rowNum++);
row.createCell(0).setCellValue(user.getUsername());
row.createCell(1).setCellValue(user.getFirstName());
row.createCell(2).setCellValue(user.getLastName());
row.createCell(3).setCellValue(user.getEMail());
}
response.setHeader("Content-disposition", "attachment; filename=" + EXCEL_FILE_NAME);
workbook.write(response.getOutputStream());
}

Answer 1

It is missing the content-type:
response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
Also use XSSFWorkbook to generate an .xlsx file:
XSSFWorkbook wb = new XSSFWorkbook();
Edit~~~~
Here is a full example that works, I use SpringBoot 2.2.2 and POI 3.15.
#GetMapping(value = "/main/export")
public void export(HttpServletResponse response) throws Exception {
// user list
List<UserDto> users = new ArrayList<>();
users.add(new UserDto(1L, "user1"));
users.add(new UserDto(2L, "user2"));
XSSFWorkbook workbook = new XSSFWorkbook();
Sheet sheet = workbook.createSheet("All Users List");
Row header = sheet.createRow(0);
header.createCell(0).setCellValue("Username");
header.createCell(1).setCellValue("First name");
header.createCell(2).setCellValue("Last name");
header.createCell(3).setCellValue("E-mail");
int rowNum = 1;
for (UserDto user : users) {
Row aRow = sheet.createRow(rowNum++);
aRow.createCell(0).setCellValue(user.getId());
aRow.createCell(1).setCellValue(user.getName());
}
response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
response.setHeader("content-disposition", "attachment; filename=myfile.xlsx");
workbook.write(response.getOutputStream());
}

Answer 2

I have same problm.
I tried using you suggestion.
#GetMapping("/download")
public void download(HttpServletResponse response) throws Exception {
List<User> users = userService.getUsers();
XSSFWorkbook workbook = new XSSFWorkbook();
Sheet sheet = workbook.createSheet("All Users List");
Row header = sheet.createRow(0);
header.createCell(0).setCellValue("Username");
header.createCell(1).setCellValue("First name");
header.createCell(2).setCellValue("Last name");
header.createCell(3).setCellValue("E-mail");
int rowNum = 1;
for (User user : users) {
Row aRow = sheet.createRow(rowNum++);
aRow.createCell(0).setCellValue(user.getUsername());
aRow.createCell(1).setCellValue(user.getFirstName());
aRow.createCell(2).setCellValue(user.getLastName());
aRow.createCell(3).setCellValue(user.getEMail());
}
response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
response.setHeader("content-disposition", "attachment; filename=myfile.xlsx");
workbook.write(response.getOutputStream());
}
But when I download from controller document i get this: