download csv file spring boot

1package net.codejava;
2 
3import java.io.IOException;
4import java.text.DateFormat;
5import java.text.SimpleDateFormat;
6import java.util.Date;
7import java.util.List;
8 
9import javax.servlet.http.HttpServletResponse;
10import org.springframework.beans.factory.annotation.Autowired;
11import org.springframework.stereotype.Controller;
12import org.springframework.web.bind.annotation.GetMapping;
13 
14import org.supercsv.io.CsvBeanWriter;
15import org.supercsv.io.ICsvBeanWriter;
16import org.supercsv.prefs.CsvPreference;
17 
18@Controller
19public class UserController {
20 
21    @Autowired
22    private UserServices service;
23     
24     
25    @GetMapping("/users/export")
26    public void exportToCSV(HttpServletResponse response) throws IOException {
27        response.setContentType("text/csv");
28        DateFormat dateFormatter = new SimpleDateFormat("yyyy-MM-dd_HH-mm-ss");
29        String currentDateTime = dateFormatter.format(new Date());
30         
31        String headerKey = "Content-Disposition";
32        String headerValue = "attachment; filename=users_" + currentDateTime + ".csv";
33        response.setHeader(headerKey, headerValue);
34         
35        /*This is where you receive the data which you wanna export to csv*/ 
36        List<User> listUsers = service.listAll();
37 
38        ICsvBeanWriter csvWriter = new CsvBeanWriter(response.getWriter(), CsvPreference.STANDARD_PREFERENCE);
39        String[] csvHeader = {"User ID", "E-mail", "Full Name", "Roles", "Enabled"};
40        String[] nameMapping = {"id", "email", "fullName", "roles", "enabled"};
41         
42        csvWriter.writeHeader(csvHeader);
43         
44        for (User user : listUsers) {
45            csvWriter.write(user, nameMapping);
46        }
47         
48        csvWriter.close();
49         
50    }
51     
52}