Download file from rest api without window.open - java

I'm trying to find a way to download file from api without window.open().
I'd like to get instant download when calling the api.
Currently downloading .xls file generated by a rest api using window.open()
API Endpoint
#GetMapping("/applications/export")
#Timed
public ResponseEntity<byte[]> exportApplicationsList() {
log.debug("REST request to export applications list");
byte[] result = applicationService.generateApplicationsListAsExcel();
if (result == null) {
return ResponseEntity.status(500).build();
}
String date = LocalDateTime.now().format(DateTimeFormatter.ofPattern("dd_MM_yyyy_HH_mm"));
return ResponseEntity.ok()
.header("Content-Disposition", "attachment; filename=liste_applications_" + date + ".xls")
.contentLength(result.length)
.contentType(MediaType.APPLICATION_OCTET_STREAM)
.body(result);
}
Service
/**
* Generate xls file from applications list.
*
* #param applications list of applications
*/
public byte[] generateApplicationsListAsExcel() {
log.info("Génération fichier xls de la liste des applications");
List<Application> applications = applicationRepository.findAll();
Collections.sort(applications);
try (InputStream is = new FileInputStream(ResourceUtils.getFile("classpath:jxls-templates/liste_applications_template.xls"))) {
try (ByteArrayOutputStream os = new ByteArrayOutputStream()) {
Context context = new Context();
context.putVar("applications", applications);
JxlsHelper.getInstance().processTemplate(is, os, context);
return os.toByteArray();
} catch (IOException e) {
log.error(e.toString());
}
} catch (IOException e) {
log.error(e.toString());
}
return null;
}
Invocation
exportApplicationsList(): void {
window.open('/api/applications/export');
}

You can return file as blob as response from backend and then use file-saver to download the file
this.http.get(`/api/applications/export`, params, { responseType: 'blob' })
.subscribe((resp: any) => {
saveAs(resp, `filename}.xlsx`)
});

Quick solution : window.location.href = url;

I used this file-saver, I think it will fulfill your needs.
this.filesService.getDownloadFile(id).subscribe(
data => {
importedSaveAs(data, name);
},
err => {
console.error(err);
});
For the backend:
#GetMapping("download-file/{id}")
public ResponseEntity<?> downloadFile(#PathVariable(value = "id") Long id) {
final Optional<FileEntity> file = fileRepository.findById(id);
if (!file.isPresent()) {
return ResponseEntity.badRequest().body(getErrorResponse("File not found"));
}
ByteArrayOutputStream downloadInputStream = amazonClient.downloadFile(file.get().getLink());
return ResponseEntity.ok()
.contentType(contentType(file.get().getName()))
.header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + file.get().getName() + "\"")
.body(downloadInputStream.toByteArray());
}

Related

Load Image/Files from Spring Boot Rest api To the Android front end

This is my controller end point that will take the request from the frontend with the filename and using that filename image/file shall be returned. It works fine while testing on postman but I have no idea how to load images/files from this end point in android.
GetMapping("downloadFile/{fileName}")
#PreAuthorize("hasRole('ADMIN') or hasRole('MODERATOR') or hasRole('USER')")
public ResponseEntity<Resource> downloadFile(#PathVariable String fileName, HttpServletRequest request) {
Resource resource = fileStorageService.loadFileAsResource(fileName);
//System.out.println(resource);
String contentType = null;
try {
contentType = request.getServletContext().getMimeType(resource.getFile().getAbsolutePath());
} catch (IOException ex) {
ex.printStackTrace();
}
if (contentType == null) {
contentType = AppConstants.DEFAULT_CONTENT_TYPE;
}
return ResponseEntity.ok().contentType(MediaType.parseMediaType(contentType))
.header(HttpHeaders.CONTENT_DISPOSITION,
String.format(AppConstants.FILE_DOWNLOAD_HTTP_HEADER, resource.getFilename()))
.body(resource);
}
And My service for this looks like..
public Resource loadFileAsResource(String fileName) {
try {
//Path filePath = this.fileStorageLocation.resolve(fileName).normalize();
Path filePath= this.fileStoragePath.resolve(fileName).normalize();
Resource resource = new UrlResource(filePath.toUri());
if (resource.exists()) {
return resource;
} else {
throw new FileStorageException(AppConstants.FILE_NOT_FOUND + fileName);
}
} catch (MalformedURLException ex) {
throw new FileStorageException(AppConstants.FILE_NOT_FOUND + fileName, ex);
}
}
I need to load image/files from here to the android frontend.
Picasso is the option to do this. just load your images with the resource you receive from server...

Java Spring boot storing a file

I am trying to store a file from user, using Java Spring boot and make a preview immediately after image upload. But now I get a 404 error on the console and when I refresh the page, the image shows up!
I tried to solve the problem by adding sleep or delay in the thread. Did not work. Here is some part of controller and service file:
public Resource getIllustrationAsResource(long id) throws MalformedURLException {
return new FileUrlResource(uploadLocation + id + ILLUSTRATION_FILE_ENDING);
}
public PostResult addIllustration(MultipartFile file) throws IOException {
Illustration illustration = getIllustrationMetadata(file);
long id = repo.insertIllustration(illustration);
storeFile(file, id);
return new PostResult(id);
}
private void storeFile(MultipartFile file, long id) throws IOException {
Path path = Paths.get(uploadLocation + id + ILLUSTRATION_FILE_ENDING);
System.out.println("storeFile path: " + path);
File uploadFile = new File(uploadLocation);
uploadFile.getParentFile().mkdirs();
try (InputStream inputStream = file.getInputStream()) {
Files.copy(inputStream, path);
}
}
Controller:
#GetMapping("/illustrations/{id}/image")
public ResponseEntity < Resource > getImageContent(#PathVariable("id") long id)
throws MalformedURLException {
Illustration illustrationInfo = service.getOneIllustration(id);
Resource body = service.getIllustrationAsResource(id);
final HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.parseMediaType(illustrationInfo.getMime()));
return new ResponseEntity < > (body, headers, HttpStatus.OK);
}
#PostMapping("/illustrations")
public PostResult postOneIllustration(#RequestParam("file") MultipartFile image)
throws IOException {
ProjectId project = projectService.getCurrentProject();
if (project == null) {
throw new EntityMissingException();
}
if (!authorizationService.loggedInUserCanCreateObjectsInProject(project)) {
throw new EntityMissingException();
}
return service.addIllustration(image);
}
Frontend:
postFile: async function(data) {
//console.log("here")
try {
let fetchPromise = catchReject(
fetch(`${window.contextPath}/illustrations`, {
method: 'POST',
body: data
})
)
const response = await fetchPromise
validateHttpOkStatus(response)
return response.json()
} catch (e) {
console.log('in postFile')
console.log(e)
// store.dispatch(addGlobalError(e))
throw e
}
},

Best practices to upload large files by chunks in Spring boot

I have A big file and i want to upload that in Server side. it's very important when occured any problem (like interrupting the internet or power cut ...) if i retry to upload, file uploaded from resume and doesn't need to send file from beginning.
I try this approach with sending file chunks but it seems that's not a good way, because a send chunks(byte arrays) directly in response Entity and this isn't good idea.
whatever if anybody can develop this approach and make this code a better code with better performance i appreciate that. does anybody known Best practice way to doing that??
and if u like my code, vote me
thanks :)
RestController
#RestController
#RequestMapping("/files")
public class Controller {
#Autowired
private MyService service;
#PutMapping("/upload/resume")
public Mono<ResponseEntity> uploadWithResume(#RequestPart("chunk")byte[] chunk,
#RequestPart("fileName")String fileName,
#RequestParam("length")Long length
) throws ParseException {
try {
return service.fileResumeUpload(chunk, fileName, length);
} catch (IOException e) {
e.printStackTrace();
return Mono.just(ResponseEntity.status(HttpStatus.PERMANENT_REDIRECT).build());
}
}
#RequestMapping(value = "/get/uploaded/size", method = RequestMethod.HEAD)
public Mono<ResponseEntity> getUploadedSize(#RequestParam("fileName") String fileName) throws IOException {
if (Files.exists(Paths.get("src/main/resources/" + fileName))) {
String size = String.valueOf(Files.size(Paths.get("src/main/resources/" + fileName)));
return Mono.just(ResponseEntity.ok()
.header("upload-offset", size)
.build());
} else{
return Mono.just(ResponseEntity.notFound()
.header("upload-offset" , "0").build());
}
}
}
Service
public Mono<ResponseEntity> fileResumeUpload(byte[] chunk , String fileName,long length) throws IOException, ParseException {
BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream("src/main/resources/" + fileName, true));
boolean uploaded = true;
try {
out.write(chunk);
} catch (IOException e) {
uploaded = false;
System.err.println("io exception");
} finally {
if (uploaded) {
out.close();
return Mono.just(ResponseEntity.ok()
.header("expiration-date", getExpirationDate())
.build());
} else {
out.close();
return Mono.just(ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).build());
}
}
}
Sending chunks with webTestClient
#Test
public void test1_upload_Expected_200StatusCode(){
try {
String fileName = "film.mkv";
RandomAccessFile raf = new RandomAccessFile(new File("src/test/resources/" + fileName), "rw");
long realSize = raf.length();
List<String> strings = webTestClient.head().uri("/files/get/uploaded/size?fileName=" + fileName)
.exchange().expectBody().returnResult().getResponseHeaders().get("upload-offset");
long uploadedSize = Long.valueOf(strings.get(0));
boolean f = false;
int sizeBuffer = 256 * 1024;
byte[] buffer = new byte[sizeBuffer];
MultiValueMap<String, Object> formData;
WebTestClient.ResponseSpec exchange = null;
System.out.println("first uploaded Size ; " + uploadedSize);
raf.seek(uploadedSize);
while (raf.read(buffer) != -1) {
formData = new LinkedMultiValueMap<>();
formData.add("fileName", fileName);
formData.add("chunk", buffer);
formData.add("length", realSize);
exchange = webTestClient.put().uri("/files/upload/resume")
.contentType(MediaType.MULTIPART_FORM_DATA)
.body(BodyInserters.fromMultipartData(formData))
.exchange();
exchange.expectStatus().isOk();
if (exchange.expectBody().returnResult().getStatus().is5xxServerError()) {
return;
}
if (uploadedSize + 256 * 1024 > realSize) {
sizeBuffer = ((int) (realSize - uploadedSize));
System.out.println(sizeBuffer);
uploadedSize = uploadedSize + sizeBuffer;
System.out.println(uploadedSize);
buffer = new byte[sizeBuffer];
f=true;
} else uploadedSize = uploadedSize + sizeBuffer;
if (f) System.out.println(uploadedSize);
//System.out.println(uploadedSize);
float percent = ((float) uploadedSize / realSize * 100);
System.out.format("%.2f\n", percent);
}
if (exchange!=null)
exchange.expectStatus().isOk();
}
catch (Exception e){
e.printStackTrace();
System.err.println("channel closed!!!");
}
}

How to give parameters to a method which implements another method

I used a jersey server and I want that a endpoint redirect to the download of a file depending on parameters.
I have difficulties with the function below :
#GET
#Path("/get/{id}/{chunk}")
public Response getDescription(#PathParam("id") String id, #PathParam("chunk") String chunk) {
{
StreamingOutput fileStream = new StreamingOutput()
{
#Override
public void write(java.io.OutputStream output, String id) throws IOException, WebApplicationException
{
try
{
if (Objects.equals(chunk, new String("init"))) {
java.nio.file.Path path = Paths.get("src/main/uploads/example/frame_init.pdf");
}
else {
java.nio.file.Path path = Paths.get("src/main/uploads/example/"+ id +".pdf");
}
byte[] data = Files.readAllBytes(path);
output.write(data);
output.flush();
}
catch (Exception e)
{
throw new WebApplicationException("File Not Found !!");
}
}
};
return Response
.ok(fileStream, MediaType.APPLICATION_OCTET_STREAM)
.header("content-disposition","attachment; filename = myfile.pdf")
.build();
}
I have a problem with passing parameters to the function write. I have my parameters id and chunk by the endpoint but I can't use it in the write method because it implements StreamingOutput().
How I can handle it ? Thank you
For java, final keyword should solve your problem.
As updated code;
#GET
#Path("/get/{id}/{chunk}")
public Response getDescription(#PathParam("id") final String id, #PathParam("chunk") final String chunk) {
{
StreamingOutput fileStream = new StreamingOutput()
{
#Override
public void write(java.io.OutputStream output, String id2) throws IOException, WebApplicationException
{
try
{
if (Objects.equals(chunk, new String("init"))) {
java.nio.file.Path path = Paths.get("src/main/uploads/example/frame_init.pdf");
}
else {
java.nio.file.Path path = Paths.get("src/main/uploads/example/"+ id2 +".pdf");
}
byte[] data = Files.readAllBytes(path);
output.write(data);
output.flush();
}
catch (Exception e)
{
throw new WebApplicationException("File Not Found !!");
}
}
};
return Response
.ok(fileStream, MediaType.APPLICATION_OCTET_STREAM)
.header("content-disposition","attachment; filename = myfile.pdf")
.build();
}

File download/save from a Jersey rest api call using ANGULARJS . file is attached with response as "Content-Disposition"

I am new to angular .. I hava java rest api which return CSV file in response as attachment as | "Content-Disposition", "attachment; filename=" | content-type :application/octet-stream
Now when i am calling this api from AngularJS using $http i am getting response.data ="" (blank)
I am using basic authorisation for security so I have to pass Header while calling calling API so can't use link click or new window open fro CSV download.
to test when i removed authorisation and hit the url in browser then CSV file is being downloaded.so no issue at server side .
I need help at angularjs side to download CSV file from web api response as attachment.
Here is my Java API Code
public class ServiceAPI {
#GET
#Produces(MediaType.APPLICATION_OCTET_STREAM)
public Response getFileAsCSVFile(){
byte[] file=null;
try {
ArrayList<> List=new ArrayList<>();// data retrieved from DB
if(null != List){
file=convertJsonToCSV(new Gson().toJson(List));
}
} catch (ParseException e) {
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return Response.ok(getBytes(file),MediaType.APPLICATION_OCTET_STREAM).header("Content-Disposition", "attachment; filename=" + "FileName.csv").build();
}
}
and Angular code :
app.controller('review', ['$scope', '$http', function ($scope, $http){
$scope.fromDate = new Date();
$scope.toDate = new Date();
$scope.minDate = new Date(
$scope.fromDate.getFullYear(),
$scope.fromDate.getMonth() - 2,
$scope.fromDate.getDate(),
$scope.toDate.getFullYear(),
$scope.toDate.getMonth() - 2,
$scope.toDate.getDate()
);
$scope.maxDate = new Date(
$scope.fromDate.getFullYear(),
$scope.fromDate.getMonth() - 2,
$scope.fromDate.getDate(),
$scope.toDate.getFullYear(),
$scope.toDate.getMonth() - 2,
$scope.toDate.getDate()
);
$scope.reviews = json;
function openSaveAsDialog(filename, content, mediaType) {
var blob = new Blob([content], {type: mediaType});
saveAs(blob, filename);
}
function callApi(url) {
// var dat=apiFactory.getServiceData(url);
// console.log(dat);
// apiFactory.getServiceData(url);
var responseType='arraybuffer';
var expectedMediaType='application/octet-stream';
$http.get(url, {
headers: {
accept: expectedMediaType
},
responseType:responseType,
cache: true,
transformResponse: function (data) {
var pdf;
if (data) {
pdf = new Blob([data], {
type: expectedMediaType
});
}
return {
response: pdf
};
}
}).then(function (data,status,headers) {
var filename='Preview.csv',
octetStreamMime = "application/octet-stream",
contentType;
headers = data.headers();
contentType = headers["content-type"] || octetStreamMime;
// openSaveAsDialog(filename, response.data, expectedMediaType);
if (navigator.msSaveBlob) {
var blob = new Blob([data], { type: contentType });
navigator.msSaveBlob(blob, filename);
} else {
var urlCreator = window.URL || window.webkitURL || window.mozURL || window.msURL;
if (urlCreator) {
// Try to use a download link
var link = document.createElement("a");
if ("download" in link) {
// Prepare a blob URL
var blob = new Blob([data.data], { type: contentType });
var url = urlCreator.createObjectURL(blob);
link.setAttribute("href", url);
link.setAttribute("download", filename);
// Simulate clicking the download link
var event = document.createEvent('MouseEvents');
event.initMouseEvent('click', true, true, window, 1, 0, 0, 0, 0, false, false, false, false, 0, null);
link.dispatchEvent(event);
} else {
// Prepare a blob URL
// Use application/octet-stream when using window.location to force download
var blob = new Blob([data], { type: octetStreamMime });
var url = urlCreator.createObjectURL(blob);
$window.location = url;
}
}
}
});
};
$scope.submit = function (fromDate, toDate) {
$scope.url = API_url;
var resp =callApi(($scope.url).split(" ").join("%20"));
console.log(resp);
};
},
]);
I have an example with spring MVC instead of JAX-RS (Jersey)
HTML:
<button ng-click="downloadPdf()" class="btn btn-primary">download PDF</button>
Angularjs controler:
$scope.downloadCsv = function () {
console.log("downloadCsv");
var fileName = "test.csv";
var a = document.createElement("a");
document.body.appendChild(a);
XxxxxxServiceCSV.downloadCsv().then(function (result) {
console.log("downloadCsv callback");
var file = new Blob([result.data], {type: 'application/csv'});
var fileURL = URL.createObjectURL(file);
a.href = fileURL;
a.download = fileName;
a.click();
});
};
Angularjs services:
angular.module('xxxxxxxxApp')
.factory('XxxxxxServiceCSV', function ($http) {
return {
downloadCsv: function () {
return $http.get('api/downloadCSV', { responseType: 'arraybuffer' }).then(function (response) {
return response;
});
}
};
});
Java code JAX-RS(spring MVC):
#RequestMapping(value = "/downloadCSV", method = RequestMethod.GET, produces = "application/csv")
public void demo(HttpServletResponse response) throws IOException {
List<String> names = new ArrayList<String>();
names.add("First Name");
names.add("Second Name");
names.add("Third Name");
names.add("Fourth Name");
BufferedWriter writer = new BufferedWriter(response.getWriter());
try {
response.setHeader("Content-Disposition", "attachment; filename=\"test.csv\"");
for (String name : names) {
writer.write(name);
writer.write(",");
}
writer.newLine();
} catch (IOException ex) {
} finally {
writer.flush();
writer.close();
}
}

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