I have implemented a controller in Spring that writes the contents to a pdf file (via input stream) to the ServletOutputStream, however when comparing the contents of the existing file and the downloaded file it appears to be corrupt.
public class DownloadFileController {
#GetMapping(value = "v0/file")
#ResponseBody
public void downloadFile(HttpServletResponse response) {
try (ServletOutputStream outputStream = response.getOutputStream();
InputStream inputStream = getFile()) {
response.setHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_OCTET_STREAM_VALUE);
response.setHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"example.pdf\"");
IOUtils.copy(inputStream, outputStream);
} catch (IOException ex) {
throw ...
}
}
private static InputStream getFile() {
return DownloadFileController.class.getResourceAsStream("/example.pdf");
}
}
The HTTP request is successful and responds with the contents of the PDF, however it is litered with: �
Edit:
The file won't always be PDF, it can also be images, word documents etc.
change
response.setHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_OCTET_STREAM_VALUE);
to
response.setHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_PDF);
Set content-type to application/pdf for downloading .pdf files.
You can use this setContentType() method to set the content-type and set the Content-Disposition in the response header using addHeader() method from HttpServletResponse class.
For example :
response.setContentType("application/pdf");
response.addHeader("Content-Disposition", "attachment; filename=example.pdf");
Turns out it was me being an idiot and interpreting the binary response as text which resulted in unknown characters.
Related
I want to return a zipped file from my server-side java using JAX-RS to the client.
I tried the following code,
#GET
public Response get() throws Exception {
final String filePath = "C:/MyFolder/My_File.zip";
final File file = new File(filePath);
final ZipOutputStream zop = new ZipOutputStream(new FileOutputStream(file);
ResponseBuilder response = Response.ok(zop);
response.header("Content-Type", "application/zip");
response.header("Content-Disposition", "inline; filename=" + file.getName());
return response.build();
}
But i'm getting exception as below,
SEVERE: A message body writer for Java class java.util.zip.ZipOutputStream, and Java type class java.util.zip.ZipOutputStream, and MIME media type application/zip was not found
SEVERE: The registered message body writers compatible with the MIME media type are:
*/* ->
com.sun.jersey.core.impl.provider.entity.FormProvider
What is wrong and how can I fix this?
You are delegating in Jersey the knowledge of how to serialize the ZipOutputStream. So, with your code you need to implement a custom MessageBodyWriter for ZipOutputStream. Instead, the most reasonable option might be to return the byte array as the entity.
Your code looks like:
#GET
public Response get() throws Exception {
final File file = new File(filePath);
return Response
.ok(FileUtils.readFileToByteArray(file))
.type("application/zip")
.header("Content-Disposition", "attachment; filename=\"filename.zip\"")
.build();
}
In this example I use FileUtils from Apache Commons IO to convert File to byte[], but you can use another implementation.
You can write the attachment data to StreamingOutput class, which Jersey will read from.
#Path("/report")
#GET
#Produces(MediaType.TEXT_PLAIN)
public Response generateReport() {
String data = "file contents"; // data can be obtained from an input stream too.
StreamingOutput streamingOutput = outputStream -> {
ZipOutputStream zipOut = new ZipOutputStream(new BufferedOutputStream(outputStream));
ZipEntry zipEntry = new ZipEntry(reportData.getFileName());
zipOut.putNextEntry(zipEntry);
zipOut.write(data); // you can set the data from another input stream
zipOut.closeEntry();
zipOut.close();
outputStream.flush();
outputStream.close();
};
return Response.ok(streamingOutput)
.type(MediaType.TEXT_PLAIN)
.header("Content-Disposition","attachment; filename=\"file.zip\"")
.build();
}
In Jersey 2.16 file download is very easy
Below is the example for the ZIP file
#GET
#Path("zipFile")
#Produces("application/zip")
public Response getFile() {
File f = new File(ZIP_FILE_PATH);
if (!f.exists()) {
throw new WebApplicationException(404);
}
return Response.ok(f)
.header("Content-Disposition",
"attachment; filename=server.zip").build();
}
I'm not sure I it's possible in Jersey to just return a stream as result of annotated method. I suppose that rather stream should be opened and content of the file written to the stream. Have a look at this blog post. I guess You should implement something similar.
I wrote a rest controller to return an image associated with a primary key. Now I wanted to load this image in the browser and I am running into issues:
(1) If I type a GET URL to the image the browser (FireFox and Chrome) don't display the image but they are seeing all the headers properly. Additionally firefox says "The image cannot be displayed because it contains errors"
(2) If I used XMLHttpRequest to create get the image using the URL I get the image but it displays only partially (the bottom half is cut off and is set to transparent).
#GetMapping("/{featureId}/loadImage")
public ResponseEntity<byte []> loadImageForId(#PathVariable long featureId, HttpServletResponse response) throws IOException {
log.info("Getting image for feature id " + featureId);
Feature feature = featureService.getFeatureById(featureId);
File file = featureService.loadImageForFeature(feature);
byte [] imageData = new byte[(int) file.length()];
FileInputStream inputStream = new FileInputStream(file);
inputStream.read(imageData);
inputStream.close();
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.parseMediaType(...));
headers.setContentLength(file.length());
response.setHeader("Content-Disposition", "inline; filename=" + file.getName());
return new ResponseEntity<byte[]>(imageData, headers, HttpStatus.OK);
}
if it is working on tomcat, you can use this tomcat's utility class :
import org.apache.tomcat.util.http.fileupload.IOUtils
for example:
response.setContentType("image/jpeg");
InputStream is = new ByteArrayInputStream(imageByteArray);
IOUtils.copy(is,response.getOutputStream());
Okay finally after hours of debugging with curl etc, I was able to verify that the response body was not getting properly encoded image (nothing to do with the headers).
This was caused due to the choice of InputStream and OutputStream objects.
Instead of using FileInputStream I switched to using ImageIO and the underlying BufferedImage to write the output to the ServletResponse as follows:
#GetMapping("/{featureId}/loadImage")
public void loadImageForId(#PathVariable long featureId, HttpServletResponse response) throws IOException {
log.info("Getting image for feature id " + featureId);
Feature feature = featureService.getFeatureById(featureId);
File imageFile = featureService.loadImageForFeature(feature);
MediaType mediaType = MediaType.parseMediaType(Files.probeContentType(imageFile.toPath()));
response.setHeader("Content-Disposition", "inline; filename=" + imageFile.getName());
response.setStatus(HttpStatus.OK.value());
response.setContentType(mediaType.toString());
response.setContentLength((int)imageFile.length());
OutputStream os = response.getOutputStream();
ImageIO.write(ImageIO.read(imageFile), mediaType.getSubtype(), os);
os.flush();
os.close();
}
This question already has answers here:
SpringBoot: Large Streaming File Upload Using Apache Commons FileUpload
(5 answers)
Closed 2 years ago.
Spring boot's default MultiPartResolver interface handles the uploading of multipart files by storing them on the local file system. Before the controller method is entered, the entire multipart file must finish uploading to the server.
We are storing all of our uploaded files directly to a database and our servers have a very small disk quota, so if a large file is uploaded, we are seeing an IOExeption - Disk quota exceeded.
Is there a way to get the stream directly from the client's incoming request before Spring's MultiPartResolver stores the file on the local filesystem so the we can stream directly to our db?
You could use apache directly, as described here https://commons.apache.org/proper/commons-fileupload/streaming.html.
#Controller
public class UploadController {
#RequestMapping("/upload")
public String upload(HttpServletRequest request) throws IOException, FileUploadException {
ServletFileUpload upload = new ServletFileUpload();
FileItemIterator iterator = upload.getItemIterator(request);
while (iterator.hasNext()) {
FileItemStream item = iterator.next();
if (!item.isFormField()) {
InputStream inputStream = item.openStream();
//...
}
}
}
}
Make sure to disable springs multipart resolving mechanism.
application.yml:
spring:
http:
multipart:
enabled: false
Actually it is not trivial task. If you would like to write stream from client right to the database, you have to process request manually. There are some libraries, that can make this task simpler. One of them is "Apache Commons FileUpload". Below very simple example, how can you process incoming multipart/form-data request by this library.
#Controller
public class Controller{
#RequestMapping("/upload")
public String upload(HttpServletRequest request){
String boundary = extractBoundary(request);
try {
MultipartStream multipartStream = new MultipartStream(request.getInputStream(),
boundary.getBytes(), 1024, null);
boolean nextPart = multipartStream.skipPreamble();
while(nextPart) {
String header = multipartStream.readHeaders();
if(header.contains("filename")){
//if input is file
OutputStream output = createDbOutputStream();
multipartStream.readBodyData(output);
output.flush();
output.close();
} else {
//if input is not file (text, checkbox etc)
ByteArrayOutputStream output = new ByteArrayOutputStream();
multipartStream.readBodyData(output);
String value = output.toString("utf-8");
//... do something with extracted value
}
nextPart = multipartStream.readBoundary();
}
} catch (IOException e) {
throw new RuntimeException(e);
}
}
private String extractBoundary(HttpServletRequest request) {
String boundaryHeader = "boundary=";
int i = request.getContentType().indexOf(boundaryHeader)+
boundaryHeader.length();
return request.getContentType().substring(i);
}
}
Header for file field will looks like:
Content-Disposition: form-data; name="fieldName"; filename="fileName.jpg"
Content-Type: image/jpeg
Header for simple field will looks like:
Content-Disposition: form-data; name="fieldName";
Note, that this snippet is just simplified example to show you direction. There is no some details like: extract field name from header, create database output stream etc. You can implement all of this stuff by your own.
Examples of multipart request's field headers you can find in RFC1867. Information about multipart/form-data RFC2388.
I'm trying to serve images from mongodb GridFS. My Controller.
#RequestMapping(value = "{id}", method = RequestMethod.GET)
public void getPhoto (#PathVariable String id, HttpServletResponse response, HttpServletRequest request) {
log.info("#getPhoto > ip of request: " + request.getRemoteAddr() + ", id: " + id);
final InputStream inputStream = resourceService.getMediaResourceById(id);
try {
IOUtils.copy(inputStream, response.getOutputStream());
response.flushBuffer();
} catch (IOException | NullPointerException e) {
log.error("#getPhoto > error with request for objectId: " + id, e);
response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
}
}
The result:
This only happens using Spring Boot. as a test when using Spring and running the exact same code i'm getting:
Writing directly to a response is discouraged in controller methods for various reasons. You are essentially responsible for almost everything yourself. The preferred way is to return something that gets converted as needed.
You already use ResponseEntity<byte[]> now. But your source is a stream and you have to create an unnecessary byte array. You can use Resource instead that wraps all sorts of input streams, be it from files or already opened input streams.
InputStreamResource inputStream = new InputStreamResource(resourceService.getMediaResourceById(id));
return new ResponseEntity<>(inputStream, HttpStatus.OK);
or as of Spring 4.1
return ResponseEntity.ok(inputStream);
Please note that produces = MediaType.IMAGE_JPEG_VALUE doesn't actually set a content type. It's used for content negotiation.
Can someone provide me a demo of sending pdf files as response ?
Endpoint is
#GET
#Path("/PDFiles")
#WebMethod(operationName = "PDFiles")
public Response pdfiles() {
LOGGER.info("Getting FPodAUMFile.");
return dao.getPDFfiles(CacheKeys.pdffile);
}
DAO would be
public Response getPDFfiles(String pdffile) {
File file_pdf = new File("D:/pdffile.pdf");
// HELP ME SEND THIS PDFFILE.PDF AND COMPLETE THE CODE HERE
}
MTOM Simplifies the way it is sent. Can someone elaborate on using MTOM also ?
You need to specify Content-Disposition header in your response and write the file into the response entity. So for e.g.:
public Response getPDFfiles(String pdffile) {
File filePdf = new File("D:/pdffile.pdf"); //You'll need to convert your file to byte array.
ContentDisposition contentDisposition = new ContentDisposition("attachment;filename=pdffile.pdf");
return Response.ok(
new StreamingOutput() {
#Override
public void write(OutputStream outputStream) throws IOException, WebApplicationException {
outputStream.write(/* Your file contents as byte[] */);
}
})
.header("Content-Disposition", contentDisposition.toString())
.header("Content-Type", "application/pdf")
.build();
}
How to convert a file to byte[] can by found here.