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Rest template read response as stream and pass to spring controller(Get InputStream with rest Template)

I have a url which download the large size zip file.It returns the response as stream.though file size is large first it returns 200(HTTPSTATUK.OK) and continues download.
I have to implement a new spring controller which call the above url through rest template.I have to read the response returned by rest template and pass to controller.initially I have implemented in below way
#GetMapping("/export/downloadFile")
public ResponseEntity<byte[]> downloadData(Model model,
#ModelAttribute(EXCEPTION_COLLECTOR) ExceptionCollector exceptionCollector,
#RequestParam("userName") String userName,
#RequestParam("startDate") Date startDate,
#RequestParam("endDate") Date endDate,
#RequestParam("reason") String reason) {
URI uri = /building url here/;
return restTemplate.exchange(uri, HttpMethod.GET, new HttpEntity<>(httpHeaders), byte[].class);
}
since I am using ResponseEntity<byte[]> , rest template waits till entire file loaded into memory.so very frequently I am getting socket timeout issue.
Do we have way to read the response as stream and return to controller.
I found few things about restTemplate.execute .
restTemplate.execute(uri,HttpMethod.GET,requestCallBack,clientHttpResponse -> {
File ret = File.createTempFile("download", ".zip",new File("/Users/bokkavijay/Desktop"));
StreamUtils.copy(clientHttpResponse.getBody(), new FileOutputStream(ret));
return ret;
});
above snippet can copy the file to our local with out time out but this is not what I need.
how can we pipe the stream in clientHttpResponse to controller ?

I found the working implementation
Controller
#GetMapping("/readResponseAsStream")
public ResponseEntity<StreamingResponseBody> downloadAsStream(Model model,HttpServletResponse response) {
HttpHeaders httpHeaders=new HttpHeaders();
httpHeaders.add("Transfer-Encoding","chunked");
httpHeaders.add("Content-Type","x-zip-compressed");
httpHeaders.add("Content-Disposition", "attachment;filename=sample.zip");
ServletOutputStream servletOutputStream=response.getOutputStream();
StreamingResponseBody downloadFile = out -> {
RequestCallback requestCallBack=request->{
request.getHeaders().add(//Add headers here);
};
ResponseExtractor<ServletOutputStream> responseExtractor = clientHttpResponse -> {
//code snippet if you want to write response stream to HttpServletResponse
byte[] buff = new byte[800000];
int bytesRead = 0;
while ((bytesRead = clientHttpResponse.getBody().read(buff)) != -1) {
servletOutputStream.write(buff, 0, bytesRead);
}
return servletOutputStream;
//Incase if you want to copy file to you local
File ret = File.createTempFile("download", ".zip",new File("Add Local system directory address here"));
StreamUtils.copy(clientHttpResponse.getBody(), new FileOutputStream(ret));
//You can copy the the clientHttpResponse.getBody() to ByteArrayInputStream and return
// Don't return clientHttpResponse.getBody() directly because rest template will close the inputStream(clientHttpResponse.getBody()) after .execute completed
//if you want to write restTemplate.execute in dao layer , pass servletOutputStream as a argument to method
};
restTemplate.execute(URL_ADDRESS,HttpMethod.GET,requestCallBack,responseExtractor);
};
return new ResponseEntity(downloadFile,httpHeaders,HttpStatus.OK);
}
If you write the response directly to HttpServletResponse , controller download the file when we access in browser

How to consume spring StreamingResponseBody in Angular 8

I have the following code in my springboot backend
#GetMapping(value = "/stream", produces = MediaType.APPLICATION_OCTET_STREAM_VALUE)
public ResponseEntity<StreamingResponseBody> stream() {
File file = new File("C:\\test\\test.mp3");
try {
InputStream is = new FileInputStream(file);
StreamingResponseBody resp = outputStream -> {
IOUtils.copy(is, outputStream);
};
return ResponseEntity.ok()
.contentType(MediaType.APPLICATION_OCTET_STREAM)
.contentLength(file.length())
.body(resp);
} catch(Exception e) {
e.printStackTrace();
}
return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
.contentType(MediaType.APPLICATION_OCTET_STREAM)
.body(null);
}
I am trying to consume it in my angular app like this
HTML
<p>{{ content }}</p>
Typescript
ngOnInit(): void {
const header = new HttpHeaders().set('Accept', 'application/octet-stream');
this.http.get('http://localhost:8080/stream', {headers: header}).subscribe(
(res: any) => {
this.content = JSON.stringify(res);
},
(err: any) => {
this.content = JSON.stringify(err);
}
);
}
However unless I specify responseType: 'text' for the get method, I get only error. Also, I tried specifying responseType as blob and arraybuffer and specified several combinations of observe: body|response|events. Only {} is shown on the page. Not sure what is wrong here.
I tried following this SO post but not of much use.
Can some one please throw some light on it? Thanks in advance.

Downloading a Csv file From angularjs Jax-Rs and java

Hello everyone i am using angularjs java and rest to implement one report. Based on UI field selected there is a call to Java Layer and from java there is some database call and the returned input stream i am downloading in a csv file.
There is one problem happening if i do the same with hitting the the same url by browser which i m passing through angularjs than i m able to download the file but if by using UI i m making the request than there is no download option and data is returned as a stream in http response to angular.
java code:
enter code here
#Path("/files")
public class DownloadCsvFile {
#GET
#Path("/csv")
#Produces({MediaType.APPLICATION_OCTET_STREAM})
public Response getFile() {
StreamingOutput outp = new StreamingOutput() {
#Override
public void write(OutputStream out) throws IOException,
WebApplicationException {
String url ="http://someurl?
indent=on&q=RCE_POST:2016&sort=id%20asc
&rows=100000&start=0&wt=csv";
final InputStreamReader is = new InputStreamReader(
((HttpURLConnection) (new URL(url)).openConnection())
.getInputStream(),
Charset.forName("UTF-8"));
IOUtils.copy(is, out);
}
};
ResponseBuilder response = Response.ok(outp);
response.header("Content-Disposition", "attachment;
filename=\"testFile_file.csv\"");
return response.build();
} }
AngularJs controller code :
enter code here
var app = angular.module('myApp', ['ngProgress']);
app.controller('myCtrl', function($scope,$http,ngProgressFactory) {
// on submit the fun is called
$scope.LMALLPeriodReport =function()
{
return $http.get("http://localhost:8080/IsaveIdeas/rest/files/csv?
parameters="+parameter)
//parameter contain the selected field in UI
.then(function (response) {
var result = response.data;
alert("printing data");
});
};
The same request from the browser http://localhost:8080/IsaveIdeas/rest/files/csv? parameters={parameter} enable me to download the file.

You can use Blob in your angularjs code like this:
....
.then(function (response) {
var fileName = "yourFileName.csv";
var a = document.createElement("a");
document.body.appendChild(a);
response.data = "\ufeff" + response.data;
var file = new Blob([response.data], {encoding:"UTF-8",type:'application/csv;charset=UTF-8'});
var fileURL = URL.createObjectURL(file);
a.href = fileURL;
a.download = fileName;
a.click();
}

How can I download zip file from controller on client side? Spring boot

I have file.zip in DB like BLOB. I want create method in Spring controller for download this file on client side.
#RequestMapping(value = "/downloadResolution/{resolutionId}", method = RequestMethod.GET)
public void downloadResolution(#PathVariable("resolutionId") Long resolutionId, HttpServletResponse response) {
Resolution resolution = resolutionService.findOne(resolutionId);
ResolutionArchive resolutionArchive = resolution.getResolutionArchive();
if (resolutionArchive == null) return;
byte[] archive = resolutionArchive.getArchive();
//this byte[] archive - my zip file from db
}
How can I change this methot In order to download this on client side?
User press download button. Methos get data from DB in byte[] and user can download it.
EDIT
I tried solution of #pleft and it work. and I knew - I use ajax for call method
function downloadResolution(resulutionId) {
$.ajax({
type: 'GET',
dataType: "json",
url: '/downloadResolution/' + resulutionId,
success: function (data) {
},
error: function (xhr, str) {
}
});
}
How realize this if I use ajax?

You can use the OutputStream of your HttpServletResponse to write your archive bytes there.
e.g.
response.setHeader("Content-Disposition", "attachment; filename=file.zip");
response.setHeader("Content-Type", "application/zip");
response.getOutputStream().write(archive);
EDIT
Sample download
#RequestMapping(value = "/downloadResolution/{resolutionId}", method = RequestMethod.GET, produces = MediaType.APPLICATION_OCTET_STREAM_VALUE)
public void downloadResolution(#PathVariable("resolutionId") Long resolutionId, HttpServletResponse response) throws IOException {
String test = "new string test bytes";
response.setHeader("Content-Disposition", "attachment; filename=file.txt");
response.getOutputStream().write(test.getBytes());
}

How to download file in Spring mvc and mongodb

Hi have written controller class like below. I am trying to get file from mongo db and try to download it.
organizationFileAttachmentService.setUser(getUser());
GridFSDBFile file = organizationFileAttachmentService.getGridFSDBFileById(new ObjectId(id), "File");
if (file != null) {
byte[] content = organizationFileAttachmentService.findByIdAndBucket(new ObjectId(id), "File");
try {
int size = content.length;
InputStream is = null;
byte[] b = new byte[size];
try {
is = new ByteArrayInputStream(content);
is.read(b);
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (is != null)
is.close();
} catch (Exception ex) {
}
}
response.setContentType(file.getContentType());
// String attachment =
// "attachment; filename=\""+file.getFilename()+"\"";
String attachment = "attachment; filename=" + file.getFilename();
// response.setContentLength(new
// Long(file.getLength()).intValue());
response.setCharacterEncoding(file.getMD5());
response.setHeader("content-Disposition", attachment);// "attachment;filename=test.xls"
// copy it to response's OutputStream
// FileCopyUtils.copy(is, response.getOutputStream());
IOUtils.copy(is, response.getOutputStream());
response.flushBuffer();
is.close();
} catch (IOException ex) {
_logger.info("Error writing file to output stream. Filename was '" + id + "'");
throw new RuntimeException("IOError writing file to output stream");
}
but i am not able to down load file. can any one help me.

In case you missed it, Spring provides various built in resource handlers.
http://docs.spring.io/spring/docs/3.2.5.RELEASE/spring-framework-reference/html/resources.html#resources-implementations
If your method returns one of those (perhaps the ByteArrayResource in your case), then you just need a couple of annotations on the interface like so:
#RequestMapping(value = "/foo/bar/{fileId}",
method = RequestMethod.GET,
produces = { MediaType.APPLICATION_OCTET_STREAM_VALUE })
#ResponseBody FileSystemResource downloadFile(Long fileId);
No fiddling with encodings and headers for you that way. I'd recommend trying that before rolling your own.
Edit: The above worked fine in Spring 3.1.4. It no longer works for 3.2.x or 4.x. Whereas previously, the produces = { MediaType.APPLICATION_OCTET_STREAM_VALUE } would cause Spring to add the appropriate headers, it now treats that as a restriction. If accessing the URL with a standard web browser, an accept header of "application/octet-stream" will not be sent. Spring will therefore return a 406 error. To get it working again, such a method needs to be re-written without the "produces" attribute. Instead, add HttpServletResponse to the method arguments and add the header inside the method. i.e.:
#RequestMapping(value = "/foo/bar/{fileId}",
method = RequestMethod.GET)
#ResponseBody FileSystemResource downloadFile(
Long fileId, HttpServletResponse response) {
...
response.setHeader( "Content-Disposition", "attachment;filename=" + fileName );
...
}
Edit redux:
Now using Spring 4.0.7 via Spring Boot 1.1.8. It would appear that setting the produces = { MediaType.APPLICATION_OCTET_STREAM_VALUE } instruction is now working again. Just having that instruction seems to be enough for all the browsers I have tried. Note however, that I have also found that it does not set the Content-Disposition, which is left as application/json. Although this doesn't seem to be an issue for browsers, I have come across bugs in PHP client applications, which seem to behave only based on the Content-Disposition. So it seems that the current solution is to do both of the above!

I have changed my request as GET and added request in anchor tag in html. Aslo changed my code as
#RequestMapping(value = "/getFileById/{id}", method = RequestMethod.GET)
public #ResponseBody
void download(#PathVariable String id, HttpServletRequest request, HttpServletResponse response) throws IOException {
organizationFileAttachmentService.setUser(getUser());
GridFSDBFile file = organizationFileAttachmentService.getGridFSDBFileById(new ObjectId(id), "File");
if (file != null) {
try {
response.setContentType(file.getContentType());
response.setContentLength((new Long(file.getLength()).intValue()));
response.setHeader("content-Disposition", "attachment; filename=" + file.getFilename());// "attachment;filename=test.xls"
// copy it to response's OutputStream
IOUtils.copyLarge(file.getInputStream(), response.getOutputStream());
} catch (IOException ex) {
_logger.info("Error writing file to output stream. Filename was '" + id + "'");
throw new RuntimeException("IOError writing file to output stream");
}
}
}
Now it is working fine for me.