Spring boot rest service to download a zip file which contains multiple file
Here is my working code I have used response.getOuptStream()
@RestController
public class DownloadFileController {
@Autowired
DownloadService service;
@GetMapping("/downloadZip")
public void downloadFile(HttpServletResponse response) {
response.setContentType("application/octet-stream");
response.setHeader("Content-Disposition", "attachment;filename=download.zip");
response.setStatus(HttpServletResponse.SC_OK);
List<String> fileNames = service.getFileName();
System.out.println("############# file size ###########" + fileNames.size());
try (ZipOutputStream zippedOut = new ZipOutputStream(response.getOutputStream())) {
for (String file : fileNames) {
FileSystemResource resource = new FileSystemResource(file);
ZipEntry e = new ZipEntry(resource.getFilename());
// Configure the zip entry, the properties of the file
e.setSize(resource.contentLength());
e.setTime(System.currentTimeMillis());
// etc.
zippedOut.putNextEntry(e);
// And the content of the resource:
StreamUtils.copy(resource.getInputStream(), zippedOut);
zippedOut.closeEntry();
}
zippedOut.finish();
} catch (Exception e) {
// Exception handling goes here
}
}
}
Service Class:-
public class DownloadServiceImpl implements DownloadService {
@Autowired
DownloadServiceDao repo;
@Override
public List<String> getFileName() {
String[] fileName = { "C:\\neon\\FileTest\\File1.xlsx", "C:\\neon\\FileTest\\File2.xlsx", "C:\\neon\\FileTest\\File3.xlsx" };
List<String> fileList = new ArrayList<>(Arrays.asList(fileName));
return fileList;
}
}
Use these Spring MVC provided abstractions to avoid loading of whole file in memory.
org.springframework.core.io.Resource
& org.springframework.core.io.InputStreamSource
This way, your underlying implementation can change without changing controller interface & also your downloads would be streamed byte by byte.
See accepted answer here which is basically using org.springframework.core.io.FileSystemResource
to create a Resource
and there is a logic to create zip file on the fly too.
That above answer has return type as void
, while you should directly return a Resource
or ResponseEntity<Resource>
.
As demonstrated in this answer, loop around your actual files and put in zip stream. Have a look at produces
and content-type
headers.
Combine these two answers to get what you are trying to achieve.