How to make file downloadable from server to Front End in Spring Boot project, Created Rest API for file downloading but not functioning as expected? - spring-boot

Question

In general, I have created rest controller for both uploading and downloading a file from front end (React) to our file system. Uploading works great, as expected. However, downloading rest api not functioning properly. it downloads only 12kb or smth like that of the file. Is there anything [configs] that I am missing in my project or what? Please help! any comment or suggestion would be appreciated thanks in advance
#GetMapping("/get")
fun getFile(#Valid data: FileDeleteDTO): ResponseEntity<Resource>{
val header = HttpHeaders()
val fileGetFromDb = baseFileUploaderAttachmentService.getByUid(data.qquuid)
if (!fileGetFromDb.isPresent)
throw FileNotFoundException()
val pathFileName = fileGetFromDb.get().filename + '.' + fileGetFromDb.get().extension
val originalFileName = fileGetFromDb.get().originalName + '.' + fileGetFromDb.get().extension
// val filePath = UPLOAD_ROOT_FOLDER + fileGetFromDb.get().path + pathFileName
val filePath = UPLOAD_ROOT_FOLDER + fileGetFromDb.get().path
// val file = File(filePath)
header.contentType = (MediaType.valueOf(fileGetFromDb.get().mime_type!!))
header.contentLength = fileGetFromDb.get().size
header.set("Content-Disposition", "attachment; filename=$originalFileName")
return ResponseEntity.ok()
.headers(header)
.body(loadFileAsResource(pathFileName,Paths.get(filePath)))
}
fun loadFileAsResource(fileName: String, fileStorageLocation: Path): Resource {
try {
val filePath = fileStorageLocation.resolve(fileName).normalize()
val resource = UrlResource(filePath.toUri())
return if (resource.exists()) {
resource
} else {
throw FileNotFoundException("File not found $fileName")
}
} catch (ex: MalformedURLException) {
throw Exception("File not found $fileName", ex)
}
}

Answer 1

I have no idea what happened but i have solved above problem by adding some header elements like below:
#RequestMapping(value = ["/download"], method = [RequestMethod.GET])
#Throws(IOException::class)
fun downloadFile(#Valid data: FileDeleteDTO): ResponseEntity<Any> {
val fileGetFromDb = baseFileUploaderAttachmentService.getByUid(data.qquuid)
val pathFileName = fileGetFromDb.get().filename + '.' + fileGetFromDb.get().extension
val originalFileName = fileGetFromDb.get().originalName + '.' + fileGetFromDb.get().extension
val filePath = UPLOAD_ROOT_FOLDER + fileGetFromDb.get().path + pathFileName
val file = File(filePath)
val resource = InputStreamResource(FileInputStream(file))
val headers = HttpHeaders()
headers.add("Content-Disposition", String.format("attachment; filename=\"%s\"", originalFileName))
headers.add("Cache-Control", "no-cache, no-store, must-revalidate")
headers.add("Pragma", "no-cache")
headers.add("Expires", "0")
return ResponseEntity.ok().headers(headers).contentLength(
file.length()
).contentType((MediaType.valueOf(fileGetFromDb.get().mime_type!!))).body(resource)
}
Just wondering does Cache control has impact on this issue? Where can i learn about headers?