Download a file from resources with SpringBoot - java

How can I get a file from reosurces / folderX / file.txt
#PostMapping(value = "/uploadFile", produces = MediaType.APPLICATION_OCTET_STREAM_VALUE)
public ResponseEntity<Resource> uploadFile(#RequestParam("file") MultipartFile file) {
/*
* FIRST I upload file
* Next, I need to return different file in this request
*/
return ResponseEntity.ok().header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + "file.txt + "\"").body();
}

You can serve a resource like this:
#GetMapping(value = "file")
public ResponseEntity<Resource> file() {
Resource resource = new ClassPathResource("folderX/file.txt");
HttpHeaders headers = new HttpHeaders();
headers.add(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"file.txt\"");
return new ResponseEntity<>(resource, headers, HttpStatus.OK);
}

Related

When trying to invoke rest api to upload a multipart file throws multipartfile resource [ABC.txt]cannot be resolved to absolute file path?

I am new to resttemplate and trying to understand how to invoke below API using restTemplate
public ResponseEntity<String> upload(#ResquestPart("file") MultipartFIle file,
#RequestParam("path") String path){
//businness logic
}
I am trying to call above as below however it fails on "java.io.filenotfoundexception multipartfile resource [ABC.txt]cannot be resolved to absolute file path"
public void uploadFile() {
Path path = Paths.get("C:/ABC.txt");
byte[] content = null;
try{
content = Files.readAllBytes(path); // All file is read in content variable
} catch(final IOException e){
}
MultipartFile file = new MockMultipartFile("ABC.txt",content);
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.MULTIPART_FORM_DATA);
headers.setContentType("Accept", Mediatype.APPLICATION_JSON_VALUE);
headers.setContentType("Content-type", Mediatype.APPLICATION_JSON_VALUE);
MultiValueMap<String, Object> obj = new LinkedMultiValueMap<String, Object>();
obj.add("file", file);
obj.add9("path", "/opt/apps");
HttpEntity<?> requestEntity = new HttpEntity<>(obj, headers);
String result = getRestTemplate().postForEntity("url", requestEntity, String.class);
}

How to download excel file in spring boot using HttpHeaders?

I am getting a resulting file but in the response I am getting gibberish symbols
here is the code I am trying
public ResponseEntity<InputStreamResource> getExcel(String filePath) throws Exception {
try {
Path excelPath = Paths.get(filePath);
byte[] excel = Files.readAllBytes(excelPath);
ByteArrayInputStream excelToByte = new ByteArrayInputStream(excel);
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
headers.add("Content-Disposition", "attachment; filename=ABCGeneratedExcel.xls");
return ResponseEntity
.ok()
.headers(headers)
.contentType(MediaType.APPLICATION_OCTET_STREAM)
.body(new InputStreamResource(excelToByte));
}
catch (NoSuchFileException e) {
System.out.prinln("does not exist");
}
You should use HttpServletResponse instead. And let Spring framework initialize it by declaring as Controller method's parameter. Because you will write the excel file as binary stream, do not define the return type.
Then write the response stream after setting the contentType and header for excel downloading.
public void getExcel(String filePath, HttpServletResponse response) {
byte[] excel = Files.readAllBytes(excelPath);
String fileName = "anyFileName.xlsx"
response.setContentType("application/vnd.ms-excel");
response.setHeader("Content-Disposition", "attachment;filename=" + fileName);
response.getWriter().write(excel); // in fact, you need to surround this by try-catch block
}
Path filePath = pathToFolder.resolve(fileName).normalize();
Resource resource = new UrlResource(filePath.toUri());
if (resource.exists()) {
return resource;
} else {
throw new NotFoundException(String.format("File %s not found", fileName));
}
Where path to File - in your directory, and file name - name of file in your directory.
Next step is:
Resource resource = service.downloadFile(fileName);
String contentType = null;
try {
contentType = request.getServletContext().getMimeType(resource.getFile().getAbsolutePath());
} catch (IOException e) {
log.info("Could not determine file type");
}
if (contentType == null) {
contentType = MediaType.APPLICATION_OCTET_STREAM_VALUE;
}
return ResponseEntity
.ok()
.contentType(MediaType.parseMediaType(contentType))
.header(HttpHeaders.CONTENT_DISPOSITION, String.format(
"%s; filename=%s", content.name().toLowerCase(), resource.getFilename()
)
)
.body(resource);
Where first %s - attachment - for downloading, and inline - for rendering file in the browser.
Second %s - name of file (note that if you are storing your file in the file system, use file name with extension).

Unable to upload file from on server to another

I am trying to upload a file on my server to another server. While doing this
I am getting this error : Resolved [org.springframework.web.multipart.support.MissingServletRequestPartException: Required request part 'file' is not present]
I have put the 'file' key in my body. I am unable to figure out why this is hapenning.
Uploading Server:
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.MULTIPART_FORM_DATA);
MultiValueMap<String, Object> body
= new LinkedMultiValueMap<>();
body.add("file", Paths.get("pathToFile").toFile());
HttpEntity<MultiValueMap<String, Object>> requestEntity
= new HttpEntity<>(body, headers);
RestTemplate restTemplate = new RestTemplate();
ResponseEntity<String> response = restTemplate
.postForEntity(url, requestEntity, String.class);
Server that we are uploading to:
#RequestMapping(value = "/api", method = RequestMethod.POST, consumes = MediaType.ALL_VALUE, produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<ResponseDTO> solveUsingJar(#RequestParam("file") MultipartFile file) {
}
I share some code to upload a file one server to another server.
STEP-1 : Upload a file in Server-1 :
#PostMapping("/upload/profile")
public UploadFileResponse uploadProfileImg(#RequestPart("file") MultipartFile file)
{
return fileService.uploadProfileImg(file);
}
STEP-2 : Upload that file in Server-2 using RestTemplate.
public String upload(MultipartFile file) throws IOException
{
ResponseEntity<UploadFileResponse> response = null;
try
{
File convFile = new File(file.getOriginalFilename());
convFile.createNewFile();
FileOutputStream fos = new FileOutputStream(convFile);
fos.write(file.getBytes());
fos.close();
LinkedMultiValueMap<String, Object> map = new LinkedMultiValueMap<>();
String uploadURI = KeyConstant.FILE_UPLOAD_API_URI+"/file"; // Server-2(file Directory) FILE_UPLOAD_API_URI : http://27.34.2.33:28181/upload/file
map.add("file", new FileSystemResource(convFile));
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.MULTIPART_FORM_DATA);
HttpEntity<LinkedMultiValueMap<String, Object>> requestEntity = new HttpEntity<>(map, headers);
RestTemplate restTemplate = new RestTemplate();
response = restTemplate.exchange(uploadURI, HttpMethod.POST, requestEntity, UploadFileResponse.class);
}
catch(Exception e) {e.printStackTrace();}
return response.getBody();
}
STEP-3 : Server-2 File Upload Rest Controller :
#PostMapping("/upload/file")
public UploadFileResponse uploadFileByDirectory(#RequestPart(value = "file") MultipartFile file)
{
return this.amazonClient.uploadFilebyDirectory(KeyConstant.AMAZON_S3_PATH, file);
}

Provide JSON response and download file simultaneously with Spring-Boot

Requirement:
I need to create a Rest API which can allows to download a file as well as a JSON response.
I already have 2 different APIs to solve the purpose, but now I need to merge these APIs to a single one.
public ResponseEntity<InputStreamResource> downloadFile1(
#RequestParam(defaultValue = DEFAULT_FILE_NAME) String fileName) throws IOException {
MediaType mediaType = MediaTypeUtils.getMediaTypeForFileName(this.servletContext, fileName);
System.out.println("fileName: " + fileName);
System.out.println("mediaType: " + mediaType);
File file = new File(DIRECTORY + "/" + fileName);
InputStreamResource resource = new InputStreamResource(new FileInputStream(file));
return ResponseEntity.ok()
// Content-Disposition
.header(HttpHeaders.CONTENT_DISPOSITION, "attachment;filename=" + file.getName())
// Content-Type
.contentType(mediaType)
// Contet-Length
.contentLength(file.length()) //
.body(resource);
}
Above is the existing code that only return a file to download but I need a json response as well.
You need to return Multipart content. See for example
https://github.com/juazugas/spring-boot-multipart/blob/master/src/main/java/com/example/demo/server/MultiEndpoint.java
The code
#GET
#Produces("multipart/mixed")
public MultipartBody getMulti2(#QueryParam("name") String name) {
List<Attachment> attachments = new LinkedList<>();
attachments.add(new Attachment("root", "application/json", service.getEntity(name)));
attachments.add(new Attachment("image", "application/octet-stream", service.getEntityData(name)));
return new MultipartBody(attachments, true);
}

File upload of CommonsMultipartFile using RestTemplate is failing

I'm trying to consume a web service that accepts a CommonsMultipartFile in the request. So, I created an HTTP client using Spring's RestTemplate. Below is the method that takes in URI and a MultipartFile as parameters. I'm trying to pass this file to the web service in the form of ByteArrayResource.
public String upload(String uri, MultipartFile file) throws IOException {
logger.info("URI: " + uri);
ByteArrayResource fileAsResource = new ByteArrayResource(file.getBytes()) {
#Override
public String getFilename() {
return file.getOriginalFilename();
}
};
MultiValueMap<String, Object> parts = new LinkedMultiValueMap<String, Object>();
parts.add("file", fileAsResource);
parts.add("fileName", file.getOriginalFilename());
HttpHeaders httpHeaders = new HttpHeaders();
httpHeaders.setContentType(MediaType.MULTIPART_FORM_DATA);
HttpEntity<MultiValueMap<String, Object>> requestEntity = new HttpEntity<MultiValueMap<String, Object>>(parts, httpHeaders);
ResponseEntity<String> responseEntity = rest.exchange(uri, HttpMethod.POST, requestEntity, String.class);
this.setStatus(responseEntity.getStatusCode());
return responseEntity.getBody();
}
This is how I'm creating a CommonsMultipartFile:
private MultipartFile getCommonsMultipartFile() throws FileNotFoundException, IOException {
File file = new File("C:\\Dummy_Test.txt");
DiskFileItemFactory factory = new DiskFileItemFactory();
FileItem fileItem = factory.createItem( "file", "multipart/form-data", false, "Dummy_Test.txt" );
IOUtils.copy(new FileInputStream(file), fileItem.getOutputStream());
MultipartFile commonsMultipartFile = new CommonsMultipartFile(fileItem);
return commonsMultipartFile;
}
But whenever I run this client to hit the web service I keep getting this error.
org.springframework.web.client.ResourceAccessException: I/O error: resource loaded from byte array cannot be resolved to absolute file path; nested exception is java.io.FileNotFoundException: resource loaded from byte array cannot be resolved to absolute file path
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:453)
at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:401)
at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:377)
at com.attikala.service.UploaderService.upload(UploaderService.java:118)
at com.attikala.service.UploaderService.main(UploaderService.java:55)
Caused by: java.io.FileNotFoundException: resource loaded from byte array cannot be resolved to absolute file path
at org.springframework.core.io.AbstractResource.getFile(AbstractResource.java:107)
at org.springframework.core.io.AbstractResource.contentLength(AbstractResource.java:116)
at org.springframework.http.converter.ResourceHttpMessageConverter.getContentLength(ResourceHttpMessageConverter.java:99)
at org.springframework.http.converter.ResourceHttpMessageConverter.write(ResourceHttpMessageConverter.java:81)
at org.springframework.http.converter.ResourceHttpMessageConverter.write(ResourceHttpMessageConverter.java:1)
at org.springframework.http.converter.FormHttpMessageConverter.writePart(FormHttpMessageConverter.java:288)
at org.springframework.http.converter.FormHttpMessageConverter.writeParts(FormHttpMessageConverter.java:252)
at org.springframework.http.converter.FormHttpMessageConverter.writeMultipart(FormHttpMessageConverter.java:242)
at org.springframework.http.converter.FormHttpMessageConverter.write(FormHttpMessageConverter.java:194)
at org.springframework.http.converter.FormHttpMessageConverter.write(FormHttpMessageConverter.java:1)
at org.springframework.web.client.RestTemplate$HttpEntityRequestCallback.doWithRequest(RestTemplate.java:588)
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:436)
... 4 more
Can someone help me in figuring out what's happening here?
Note: If I use the below code to upload the file, it works perfectly fine.
public String upload(String uri) {
LinkedMultiValueMap<String, Object> map = new LinkedMultiValueMap<>();
FileSystemResource value = new FileSystemResource(new File("C:\\Dummy_Test.txt"));
map.add("file", value);
map.add("fileName", "Dummy_Test.txt");
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.MULTIPART_FORM_DATA);
HttpEntity<LinkedMultiValueMap<String, Object>> requestEntity = new HttpEntity<>(map, headers);
RestTemplate restTemplate = new RestTemplate();
ResponseEntity<String> responseEntity = restTemplate.exchange(uri, HttpMethod.POST, requestEntity, String.class);
return responseEntity.getBody();
}
So, I'm thinking, do I need to provide absolute path always for the file I'm uploading? I know I'm missing something here. Don't know what.
Thanks.
Finally, I found what's happening.
Here I go -
when this statement
ResponseEntity<String> responseEntity = rest.exchange(uri, HttpMethod.POST, requestEntity, String.class);
gets executed, behind the scenes it's trying to extract the file of type java.io.File from the MultipartFile passed, and then get the file length. But MultipartFile is not of that type and as a result it was throwing an exception.
To fix that I had to also override contentLength() method when creating an instance of ByteArrayResource. Ta-da!
ByteArrayResource fileAsResource = new ByteArrayResource(file.getBytes()) {
#Override
public String getFilename() {
return file.getOriginalFilename();
}
#Override
public long contentLength() throws IOException {
return file.getSize();
}
};
Hope this helps if anyone runs into the same problem.
The accepted answer did not work. In my case I had to override the getFile(), see my solution below.
registry.addResourceHandler("/my-app/user-tracking-script.js")
.setCachePeriod(0)
.resourceChain(false)
.addResolver(new ResourceResolver() {
#Override
public Resource resolveResource(final HttpServletRequest request, final String requestPath, final List<? extends Resource> locations, final ResourceResolverChain chain) {
try {
final HttpHeaders headers = new HttpHeaders();
headers.setAccept(Arrays.asList(MediaType.APPLICATION_OCTET_STREAM));
final HttpEntity<String> entity = new HttpEntity<>(headers);
// RELEVANT PART BELOW
final ResponseEntity<byte[]> response = restTemplate.exchange(userTrackingScript, HttpMethod.GET, entity, byte[].class);
final ByteArrayResource fileAsResource = new ByteArrayResource(response.getBody()) {
#Override
public File getFile() throws IOException {
final File tempFile = File.createTempFile("user-tracking", ".js");
try (final FileOutputStream out = new FileOutputStream(tempFile)) {
IOUtils.copy(new ByteArrayInputStream(response.getBody()), out);
}
return tempFile;
}
};
return fileAsResource;
} catch (final Exception e) {
log.error("Could not download user-tracking-script.js for URL: {}", userTrackingScript, e);
}
return null;
}
#Override
public String resolveUrlPath(final String resourcePath, final List<? extends Resource> locations, final ResourceResolverChain chain) {
log.error("Unexpected call to resolveUrlPath by {}", resourcePath);
return null;
}
})
;

Categories

Resources