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I have a requirement where I need to download a PDF from the website. The PDF needs to be generated within the code, which I thought would be a combination of freemarker and a PDF generation framework like iText. Any better way?
However, my main problem is how do I allow the user to download a file through a Spring Controller?
#RequestMapping(value = "/files/{file_name}", method = RequestMethod.GET)
public void getFile(
#PathVariable("file_name") String fileName,
HttpServletResponse response) {
try {
// get your file as InputStream
InputStream is = ...;
// copy it to response's OutputStream
org.apache.commons.io.IOUtils.copy(is, response.getOutputStream());
response.flushBuffer();
} catch (IOException ex) {
log.info("Error writing file to output stream. Filename was '{}'", fileName, ex);
throw new RuntimeException("IOError writing file to output stream");
}
}
Generally speaking, when you have response.getOutputStream(), you can write anything there. You can pass this output stream as a place to put generated PDF to your generator. Also, if you know what file type you are sending, you can set
response.setContentType("application/pdf");
I was able to stream line this by using the built in support in Spring with it's ResourceHttpMessageConverter. This will set the content-length and content-type if it can determine the mime-type
#RequestMapping(value = "/files/{file_name}", method = RequestMethod.GET)
#ResponseBody
public FileSystemResource getFile(#PathVariable("file_name") String fileName) {
return new FileSystemResource(myService.getFileFor(fileName));
}
You should be able to write the file on the response directly. Something like
response.setContentType("application/pdf");
response.setHeader("Content-Disposition", "attachment; filename=\"somefile.pdf\"");
and then write the file as a binary stream on response.getOutputStream(). Remember to do response.flush() at the end and that should do it.
With Spring 3.0 you can use the HttpEntity return object. If you use this, then your controller does not need a HttpServletResponse object, and therefore it is easier to test.
Except this, this answer is relative equals to the one of Infeligo.
If the return value of your pdf framework is an byte array (read the second part of my answer for other return values) :
#RequestMapping(value = "/files/{fileName}", method = RequestMethod.GET)
public HttpEntity<byte[]> createPdf(
#PathVariable("fileName") String fileName) throws IOException {
byte[] documentBody = this.pdfFramework.createPdf(filename);
HttpHeaders header = new HttpHeaders();
header.setContentType(MediaType.APPLICATION_PDF);
header.set(HttpHeaders.CONTENT_DISPOSITION,
"attachment; filename=" + fileName.replace(" ", "_"));
header.setContentLength(documentBody.length);
return new HttpEntity<byte[]>(documentBody, header);
}
If the return type of your PDF Framework (documentBbody) is not already a byte array (and also no ByteArrayInputStream) then it would been wise NOT to make it a byte array first. Instead it is better to use:
InputStreamResource,
PathResource (since Spring 4.0) or
FileSystemResource,
example with FileSystemResource:
#RequestMapping(value = "/files/{fileName}", method = RequestMethod.GET)
public HttpEntity<byte[]> createPdf(
#PathVariable("fileName") String fileName) throws IOException {
File document = this.pdfFramework.createPdf(filename);
HttpHeaders header = new HttpHeaders();
header.setContentType(MediaType.APPLICATION_PDF);
header.set(HttpHeaders.CONTENT_DISPOSITION,
"attachment; filename=" + fileName.replace(" ", "_"));
header.setContentLength(document.length());
return new HttpEntity<byte[]>(new FileSystemResource(document),
header);
}
If you:
Don't want to load the whole file into a byte[] before sending to the response;
Want/need to send/download it via InputStream;
Want to have full control of the Mime Type and file name sent;
Have other #ControllerAdvice picking up exceptions for you (or not).
The code below is what you need:
#RequestMapping(value = "/stuff/{stuffId}", method = RequestMethod.GET)
public ResponseEntity<FileSystemResource> downloadStuff(#PathVariable int stuffId)
throws IOException {
String fullPath = stuffService.figureOutFileNameFor(stuffId);
File file = new File(fullPath);
long fileLength = file.length(); // this is ok, but see note below
HttpHeaders respHeaders = new HttpHeaders();
respHeaders.setContentType("application/pdf");
respHeaders.setContentLength(fileLength);
respHeaders.setContentDispositionFormData("attachment", "fileNameIwant.pdf");
return new ResponseEntity<FileSystemResource>(
new FileSystemResource(file), respHeaders, HttpStatus.OK
);
}
More on setContentLength(): First of all, the content-length header is optional per the HTTP 1.1 RFC. Still, if you can provide a value, it is better. To obtain such value, know that File#length() should be good enough in the general case, so it is a safe default choice.
In very specific scenarios, though, it can be slow, in which case you should have it stored previously (e.g. in the DB), not calculated on the fly. Slow scenarios include: if the file is very large, specially if it is on a remote system or something more elaborated like that - a database, maybe.
InputStreamResource
If your resource is not a file, e.g. you pick the data up from the DB, you should use InputStreamResource. Example:
InputStreamResource isr = new InputStreamResource(...);
return new ResponseEntity<InputStreamResource>(isr, respHeaders, HttpStatus.OK);
Do
Return ResponseEntity<Resource> from a handler method
Specify Content-Type
Set Content-Disposition if necessary:
filename
type
inline to force preview in a browser
attachment to force a download
Example
#Controller
public class DownloadController {
#GetMapping("/downloadPdf.pdf")
// 1.
public ResponseEntity<Resource> downloadPdf() {
FileSystemResource resource = new FileSystemResource("/home/caco3/Downloads/JMC_Tutorial.pdf");
// 2.
MediaType mediaType = MediaTypeFactory
.getMediaType(resource)
.orElse(MediaType.APPLICATION_OCTET_STREAM);
HttpHeaders headers = new HttpHeaders();
headers.setContentType(mediaType);
// 3
ContentDisposition disposition = ContentDisposition
// 3.2
.inline() // or .attachment()
// 3.1
.filename(resource.getFilename())
.build();
headers.setContentDisposition(disposition);
return new ResponseEntity<>(resource, headers, HttpStatus.OK);
}
}
Explanation
Return ResponseEntity<Resource>
When you return a ResponseEntity<Resource>, the ResourceHttpMessageConverter writes file contents
Examples of Resource implementations:
ByteArrayResource - based in byte[]
FileSystemResource - for a File or a Path
UrlResource - retrieved from java.net.URL
GridFsResource - a blob stored in MongoDB
ClassPathResource - for files in classpath, for example files from resources directory. My answer to question "Read file from resources folder in Spring Boot" explains how to locate the resource in classpath in details
Specify Content-Type explicitly:
Reason: see "FileSystemResource is returned with content type json" question
Options:
Hardcode the header
Use the MediaTypeFactory from Spring. The MediaTypeFactory maps Resource to MediaType using the /org/springframework/http/mime.types file
Use a third party library like Apache Tika
Set Content-Disposition if necessary:
About Content-Disposition header:
The first parameter in the HTTP context is either inline (default value, indicating it can be displayed inside the Web page, or as the Web page) or attachment (indicating it should be downloaded; most browsers presenting a 'Save as' dialog, prefilled with the value of the filename parameters if present).
Use ContentDisposition in application:
To preview a file in a browser:
ContentDisposition disposition = ContentDisposition
.inline()
.filename(resource.getFilename())
.build();
To force a download:
ContentDisposition disposition = ContentDisposition
.attachment()
.filename(resource.getFilename())
.build();
Use InputStreamResource carefully:
Specify Content-Length using the HttpHeaders#setContentLength method if:
The length is known
You use InputStreamResource
Reason: Spring won't write Content-Length for InputStreamResource because Spring can't determine the length of the resource. Here is a snippet of code from ResourceHttpMessageConverter:
#Override
protected Long getContentLength(Resource resource, #Nullable MediaType contentType) throws IOException {
// Don't try to determine contentLength on InputStreamResource - cannot be read afterwards...
// Note: custom InputStreamResource subclasses could provide a pre-calculated content length!
if (InputStreamResource.class == resource.getClass()) {
return null;
}
long contentLength = resource.contentLength();
return (contentLength < 0 ? null : contentLength);
}
In other cases Spring sets the Content-Length:
~ $ curl -I localhost:8080/downloadPdf.pdf | grep "Content-Length"
Content-Length: 7554270
This code is working fine to download a file automatically from spring controller on clicking a link on jsp.
#RequestMapping(value="/downloadLogFile")
public void getLogFile(HttpSession session,HttpServletResponse response) throws Exception {
try {
String filePathToBeServed = //complete file name with path;
File fileToDownload = new File(filePathToBeServed);
InputStream inputStream = new FileInputStream(fileToDownload);
response.setContentType("application/force-download");
response.setHeader("Content-Disposition", "attachment; filename="+fileName+".txt");
IOUtils.copy(inputStream, response.getOutputStream());
response.flushBuffer();
inputStream.close();
} catch (Exception e){
LOGGER.debug("Request could not be completed at this moment. Please try again.");
e.printStackTrace();
}
}
Below code worked for me to generate and download a text file.
#RequestMapping(value = "/download", method = RequestMethod.GET)
public ResponseEntity<byte[]> getDownloadData() throws Exception {
String regData = "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.";
byte[] output = regData.getBytes();
HttpHeaders responseHeaders = new HttpHeaders();
responseHeaders.set("charset", "utf-8");
responseHeaders.setContentType(MediaType.valueOf("text/html"));
responseHeaders.setContentLength(output.length);
responseHeaders.set("Content-disposition", "attachment; filename=filename.txt");
return new ResponseEntity<byte[]>(output, responseHeaders, HttpStatus.OK);
}
What I can quickly think of is, generate the pdf and store it in webapp/downloads/< RANDOM-FILENAME>.pdf from the code and send a forward to this file using HttpServletRequest
request.getRequestDispatcher("/downloads/<RANDOM-FILENAME>.pdf").forward(request, response);
or if you can configure your view resolver something like,
<bean id="pdfViewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass"
value="org.springframework.web.servlet.view.JstlView" />
<property name="order" value=”2″/>
<property name="prefix" value="/downloads/" />
<property name="suffix" value=".pdf" />
</bean>
then just return
return "RANDOM-FILENAME";
The following solution work for me
#RequestMapping(value="/download")
public void getLogFile(HttpSession session,HttpServletResponse response) throws Exception {
try {
String fileName="archivo demo.pdf";
String filePathToBeServed = "C:\\software\\Tomcat 7.0\\tmpFiles\\";
File fileToDownload = new File(filePathToBeServed+fileName);
InputStream inputStream = new FileInputStream(fileToDownload);
response.setContentType("application/force-download");
response.setHeader("Content-Disposition", "attachment; filename="+fileName);
IOUtils.copy(inputStream, response.getOutputStream());
response.flushBuffer();
inputStream.close();
} catch (Exception exception){
System.out.println(exception.getMessage());
}
}
something like below
#RequestMapping(value = "/download", method = RequestMethod.GET)
public void getFile(HttpServletResponse response) {
try {
DefaultResourceLoader loader = new DefaultResourceLoader();
InputStream is = loader.getResource("classpath:META-INF/resources/Accepted.pdf").getInputStream();
IOUtils.copy(is, response.getOutputStream());
response.setHeader("Content-Disposition", "attachment; filename=Accepted.pdf");
response.flushBuffer();
} catch (IOException ex) {
throw new RuntimeException("IOError writing file to output stream");
}
}
You can display PDF or download it examples here
If it helps anyone. You can do what the accepted answer by Infeligo has suggested but just put this extra bit in the code for a forced download.
response.setContentType("application/force-download");
In my case I'm generating some file on demand, so also url has to be generated.
For me works something like that:
#RequestMapping(value = "/files/{filename:.+}", method = RequestMethod.GET, produces = "text/csv")
#ResponseBody
public FileSystemResource getFile(#PathVariable String filename) {
String path = dataProvider.getFullPath(filename);
return new FileSystemResource(new File(path));
}
Very important is mime type in produces and also that, that name of the file is a part of the link so you has to use #PathVariable.
HTML code looks like that:
<a th:href="#{|/dbreport/files/${file_name}|}">Download</a>
Where ${file_name} is generated by Thymeleaf in controller and is i.e.: result_20200225.csv, so that whole url behing link is: example.com/aplication/dbreport/files/result_20200225.csv.
After clicking on link browser asks me what to do with file - save or open.
I had to add this to download any file
response.setContentType("application/octet-stream");
response.setHeader("Content-Disposition",
"attachment;filename="+"file.txt");
all code:
#Controller
public class FileController {
#RequestMapping(value = "/file", method =RequestMethod.GET)
#ResponseBody
public FileSystemResource getFile(HttpServletResponse response) {
final File file = new File("file.txt");
response.setContentType("application/octet-stream");
response.setHeader("Content-Disposition",
"attachment;filename="+"file.txt");
return new FileSystemResource(file);
}
}
This can be a useful answer.
Is it ok to export data as pdf format in frontend?
Extending to this, adding content-disposition as an attachment(default) will download the file. If you want to view it, you need to set it to inline.
I have a question that makes my head ache.
First, my project structure looks like below.
I made a controller, which returns image(*.png) file to the appropriate request.
The code of controller is written below.
#Controller
public class ImageController {
#GetMapping(value = "/ImageStore.do", produces = MediaType.IMAGE_PNG_VALUE)
public #ResponseBody byte[] getStoreImage(HttpServletRequest request) throws IOException {
String image_name = request.getParameter("image_name");
Resource resource = null;
try {
resource = new ClassPathResource("/images/stores/" + image_name);
if(resource == null) {
throw new NullPointerException();
}
} catch(NullPointerException e) {
resource = new ClassPathResource("/images/stores/noimage.png");
}
InputStream inputStream = resource.getInputStream();
return IOUtils.toByteArray(inputStream);
}
}
Q1. I added try-catch phrase to send noimage.png if the request parameter is wrong, or if the filename of request parameter image_name does not exist. But it doesn't seem to work, and it gives me log saying
class path resource [images/stores/noima.png] cannot be opened because it does not exist
(If you need to know the full stack trace, I will comment below.)
Q2. I have 2 image files, hello.png and noimage.png in the folder /resources/images/stores/. I can read noimage.png correctly, but if I make request localhost:8080/ImageStore.do?image_name=hello.png, then it makes an error, making the same log in Q1.
There's no reason to think that the constructor would result in a null value.
The exception you are getting is likely from the getInputStream method, which is documented to throw
FileNotFoundException - if the underlying resource doesn't exist
IOException - if the content stream could not be opened
A slight adjustment might help
#Controller
public class ImageController {
#GetMapping(value = "/ImageStore.do", produces = MediaType.IMAGE_PNG_VALUE)
public #ResponseBody byte[] getStoreImage(HttpServletRequest request) throws IOException {
InputStream is = null;
try {
String image_name = request.getParameter("image_name");
is = new ClassPathResource("/images/stores/" + image_name).getInputStream();
} catch(FileNotFoundException e) {
is = new ClassPathResource("/images/stores/noimage.png").getInputStream();
}
return IOUtils.toByteArray(is);
}
}
You should include the stack trace, and exception message, which might assist understanding your second query, but I would check that the file really does exist, with the exact name you're using.
I've tried the various ways given in Stackoverflow, maybe I missed something.
I have an Android client (whose code I can't change) which is currently getting an image like this:
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.connect();
Where url is the location of the image (static resource on CDN). Now my Spring Boot API endpoint needs to behave like a file resource in the same way so that the same code can get images from the API (Spring boot version 1.3.3).
So I have this:
#ResponseBody
#RequestMapping(value = "/Image/{id:.+}", method = RequestMethod.GET, consumes = MediaType.ALL_VALUE, produces = MediaType.IMAGE_JPEG_VALUE)
public ResponseEntity<byte[]> getImage(#PathVariable("id")String id) {
byte[] image = imageService.getImage(id); //this just gets the data from a database
return ResponseEntity.ok(image);
}
Now when the Android code tries to get http://someurl/image1.jpg I get this error in my logs:
Resolving exception from handler [public
org.springframework.http.ResponseEntity
com.myproject.MyController.getImage(java.lang.String)]:
org.springframework.web.HttpMediaTypeNotAcceptableException: Could not
find acceptable representation
Same error happens when I plug http://someurl/image1.jpg into a browser.
Oddly enough my tests check out ok:
Response response = given()
.pathParam("id", "image1.jpg")
.when()
.get("MyController/Image/{id}");
assertEquals(HttpStatus.OK.value(), response.getStatusCode());
byte[] array = response.asByteArray(); //byte array is identical to test image
How do I get this to behave like an image being served up in the normal way? (Note I can't change the content-type header that the android code is sending)
EDIT
Code after comments (set content type, take out produces):
#RequestMapping(value = "/Image/{id:.+}", method = RequestMethod.GET, consumes = MediaType.ALL_VALUE)
public ResponseEntity<byte[]> getImage(#PathVariable("id")String id, HttpServletResponse response) {
byte[] image = imageService.getImage(id); //this just gets the data from a database
response.setContentType(MediaType.IMAGE_JPEG_VALUE);
return ResponseEntity.ok(image);
}
In a browser this just seems to give a stringified junk (byte to chars i guess). In Android it doesn't error, but the image doesn't show.
I believe this should work:
#RequestMapping(value = "/Image/{id:.+}", method = RequestMethod.GET)
public ResponseEntity<byte[]> getImage(#PathVariable("id") String id) {
byte[] image = imageService.getImage(id);
return ResponseEntity.ok().contentType(MediaType.IMAGE_JPEG).body(image);
}
Notice that the content-type is set for ResponseEntity, not for HttpServletResponse directly.
Finally fixed this... I had to add a ByteArrayHttpMessageConverter to my WebMvcConfigurerAdapter subclass:
#Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
final ByteArrayHttpMessageConverter arrayHttpMessageConverter = new ByteArrayHttpMessageConverter();
final List<MediaType> list = new ArrayList<>();
list.add(MediaType.IMAGE_JPEG);
list.add(MediaType.APPLICATION_OCTET_STREAM);
arrayHttpMessageConverter.setSupportedMediaTypes(list);
converters.add(arrayHttpMessageConverter);
super.configureMessageConverters(converters);
}
In case you don't know the file/mime type you can do this.... I've done this where i take an uploaded file and replace the file name with a guid and no extension and browsers / smart phones are able to load the image no issues.
the second is to serve a file to be downloaded.
#RestController
#RequestMapping("img")
public class ImageController {
#GetMapping("showme")
public ResponseEntity<byte[]> getImage() throws IOException{
File img = new File("src/main/resources/static/test.jpg");
return ResponseEntity.ok().contentType(MediaType.valueOf(FileTypeMap.getDefaultFileTypeMap().getContentType(img))).body(Files.readAllBytes(img.toPath()));
}
#GetMapping("thing")
public ResponseEntity<byte[]> what() throws IOException{
File file = new File("src/main/resources/static/thing.pdf");
return ResponseEntity.ok()
.header("Content-Disposition", "attachment; filename=" +file.getName())
.contentType(MediaType.valueOf(FileTypeMap.getDefaultFileTypeMap().getContentType(file)))
.body(Files.readAllBytes(file.toPath()));
}
}
UPDATE in java 9+ you need to add compile 'com.sun.activation:javax.activation:1.2.0' to your dependencies this has also been moved or picked up by jakarta.see this post
Using Apache Commons, you can do this and expose the image on an endpoint
#RequestMapping(value = "/image/{imageid}",method= RequestMethod.GET,produces = MediaType.IMAGE_JPEG_VALUE)
public #ResponseBody byte[] getImageWithMediaType(#PathVariable int imageid) throws IOException {
InputStream in = new ByteArrayInputStream(getImage(imageid));
return IOUtils.toByteArray(in);
}
All images will be served at endpoint /image/{imageid}
My problem is that I am getting the wrong sized file on the client side. Here is my #Controller ...
#RequestMapping(value = "/download/{id}", method = RequestMethod.GET)
public ResponseEntity<?> download(final HttpServletRequest request,
final HttpServletResponse response,
#PathVariable("id") final int id) throws IOException {
try {
// Pseudo-code for retrieving file from ID.
Path zippath = getZipFile(id);
if (!Files.exists(zippath)) {
throw new IOException("File not found.");
}
ResponseEntity<InputStreamResource> result;
return ResponseEntity.ok()
.contentLength(Files.size(zippath))
.contentType(MediaType.APPLICATION_OCTET_STREAM)
.body(new InputStreamResource(new FileInputStream(zippath.toFile())));
} catch (Exception ex) {
// ErrorInfo is another class, unimportant
return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(new ErrorInfo(ex));
}
}
... and here is my client-side code using angular-file-saver ...
$http({url: "export/download/" + exportitem.exportId, withCredentials: true})
.then(function(response) {
function str2bytes(str) {
var bytes = new Uint8Array(str.length);
for (var i=0; i<str.length; i++) {
bytes[i] = str.charCodeAt(i);
}
return bytes;
}
var blob = new Blob([str2bytes(response.data)], {type: 'application/octet-stream'});
FileSaver.saveAs(blob, "download.zip");
}, $exceptionHandler);
The original file is 935673 bytes but response.data is 900728 and passing it through the transformation to Uint8Array results in a Blob that is 900728 in size as well. Either way, the resulting saved file is 900728 bytes (34945 bytes shy). Also it is not quite the same in what gets written. It seems to slightly get bloated but then the last part just seems to be truncated. Any ideas what I might be doing wrong?
UPDATE
I just updated my controller method to be the following and got the exact same result. Grrr.
#RequestMapping(value = "/download/{id}", method = RequestMethod.GET)
public void download(final HttpServletRequest request,
final HttpServletResponse response,
#PathVariable("id") final int id) throws IOException {
// Pseudo-code for retrieving file from ID.
Path zippath = getZipFile(id);
if (!Files.exists(zippath)) {
throw new IOException("File not found.");
}
response.setContentType("application/zip");
response.setHeader("Content-Disposition",
"attachment; filename=download.zip");
InputStream inputStream = new FileInputStream(zippath.toFile());
org.apache.commons.io.IOUtils.copy(inputStream, response.getOutputStream());
response.flushBuffer();
inputStream.close();
}
So the problem turned out to be angular's $http service. I also tried jQuery's ajax method. Both gave the same result. If I instead use the native XMLHttpRequest it works correctly. So the Java code was sound. I first verified this by exposing the file directly to the internet and then both using curl and directly accessing in the browser I managed to download the file of the correct size. Then I found this solution so that I could also download the file via javascript.
var xhr = new XMLHttpRequest();
xhr.open('GET', url, true);
xhr.responseType = "blob";
xhr.withCredentials = true;
xhr.onreadystatechange = function (){
if (xhr.readyState === 4) {
var blob = xhr.response;
FileSaver.saveAs(blob, filename);
}
};
xhr.send();
Why does angular or jQuery give the wrong result? I still don't know but if anyone wishes to give an answer that uses those it would be appreciated.
responseType: blob
did the trick for a zip file
Angular 2 +
this.http.get('http://localhost:8080/export', { responseType: ResponseContentType.Blob })
.subscribe((res: any) => {
const blob = new Blob([res._body], { type: 'application/zip' });
saveAs(blob, "fileName.zip");
i just stumbled over the 'responseType' in $http requests, you are probably looking for 'blob': https://docs.angularjs.org/api/ng/service/$http#usage
I have the following controller method:
#RequestMapping(value = { "/member/uploadExternalImage",
"/member/uploadExternalImage" }, method = RequestMethod.GET)
public String handleFileUpload(#RequestParam String url, RedirectAttributes redirectAttributes
) throws IOException {
byte[] binaryFile = IOUtils.toByteArray(
new URL(url)
.openStream());
File file = File.createTempFile("tmp", ".txt", new File(System.getProperty("user.dir")));
FileUtils.writeByteArrayToFile(file, binaryFile);
redirectAttributes.addFlashAttribute(file);
return "redirect:/member/uploadImage";
}
Here I get external link, download file by this link and redirect it to the another controller:
It looks like this:
#RequestMapping(value = { "/member/createCompany/uploadImage",
"/member/uploadImage" })
#ResponseBody
public ResponseEntity<String> handleFileUpload(#Validated MultipartFileWrapper file,
BindingResult result, Principal principal) throws IOException {
MultipartFileWrapper:
#Component
public class MultipartFileWrapper {
#Extensions(imageFormats = {".jpg",".png",".gif",".bmp"}, videoFormats = {".mp4",".mov"})
MultipartFile multipartFile;
...
}
But redirect doesn't happen properly. It breaks on validation. Accepted multipartFile is null.
How to fix it ?
P.S.
I tryed this
File file = File.createTempFile("tmp", ".jpg", new File(System.getProperty("user.dir")));
FileUtils.writeByteArrayToFile(file, binaryFile);
FileItem fileItem = new DiskFileItem("trololo", ".jpg", false, "fileName", 1024_000_0, file);
fileItem.getOutputStream();
fileItem.getInputStream();
MultipartFile multipartFile = new CommonsMultipartFile(fileItem);
MultipartFileWrapper wrapper = new MultipartFileWrapper();
wrapper.setMultipartFile(multipartFile);
redirectAttributes.addFlashAttribute(wrapper);
return "redirect:/member/uploadImage";
it redirects correctly but size equals 0
You add a File object as a flash attribute. So you will get it in the Model for the redirected request. But I cannot imagine how you could get it in a MultipartFile which is for uploaded files. IMHO your second controller should be:
#RequestMapping(value = { "/member/createCompany/uploadImage",
"/member/uploadImage" })
#ResponseBody
public ResponseEntity<String> handleFileUpload(Model model, Principal principal) throws IOException {
File file = (File) model.getAttribute("file");
...
As shown the code snippet below, just read the file from input stream and write it into the output stream,
final File TEST_FILE = new File("C:/Users/arrows.gif");
final DiskFileItem diskFileItem = new DiskFileItem("file", "image/jpeg", true, TEST_FILE.getName(), 100000000, TEST_FILE.getParentFile());
InputStream input = new FileInputStream(TEST_FILE);
OutputStream os = diskFileItem.getOutputStream();
int ret = input.read();
while ( ret != -1 )
{
os.write(ret);
ret = input.read();
}
os.flush();
MultipartFile multipartFile = new CommonsMultipartFile(diskFileItem);
redirectAttributes.addFlashAttribute("multipartFile", multipartFile);
return "redirect:request2";
In the "request2" mapping method, just get it from model map,
I hope it should resolve the issue.
I believe the multipartFile is null because it does not exist in the request. You add a file attribute to the redirect attributes, but that is not going to be bound to the MultipartFileWrapper.
Try wrapping your file in a CommonsMultipartFile or MockMultipartFile before redirecting. This was clearly a bad advice since this is no multiform request, and no binding will take place.
The best thing to do would be to handle the file content directly or create a separate method where you handle the file content either it comes from external download or user upload. Then you can add the file as a flash attribute and redirect to this method from both your handleFileUpload methods.
In the common method you will have to pick up the file instance from the model. (like described by Serge Ballesta)