Develop Reference

Avoid CoyoteOutputStream object signature in spring rest file download call

I own a mock project maven spring-rest with the end point
#RequestMapping(value = "/rest/{nid}/{fileName:.+}", method = RequestMethod.GET, produces = MediaType.APPLICATION_PDF_VALUE)
public String getPjSae(#PathVariable String nid, #PathVariable String fileName, HttpServletResponse response) throws IOException {
LOGGER.info("NID : " + nid);
LOGGER.info("NOM FICHIER : " + fileName);
File file = new File(saePath+File.separatorChar + fileName);
LOGGER.info("CHEMIN PJ : " + file);
if (file.exists()) {
InputStream inputStream = new FileInputStream(file); //load the file
// here I use Commons IO API to copy this file to the response output stream, I don't know which API you use.
IOUtils.copy(inputStream, response.getOutputStream());
// here we define the content of this file to tell the browser how to handle it
response.setContentType("application/pdf");
response.setHeader("Content-disposition", "attachment;filename=" + fileName + ".pdf");
response.flushBuffer();
}
return response.getOutputStream().toString();
}
I get the downloaded file and convert it to base64 to write it to an XML file. I have to make the comparison later and the problem is the writing of the signature of the object in the byte stream of the base 64: CoyoteOutputStream
At the end of each base64 of pdf I have a piece:
CnN0YXJ0eHJlZgo0NjkyOAolJUVPRgpvcmcuYXBhY2hlLmNhdGFsaW5hLmNvbm5lY3Rvci5Db3lvdGVPdXRwdXRTdHJlYW1ANDA4YTViYzI=
that is different each time because:
startxref
46928
%% EOF
org.apache.catalina.connector.CoyoteOutputStream#408a5bc2
So, this pit but comparison because : #408a5bc2 is unique

You eventually return this:
return response.getOutputStream().toString();
This returns the default toString output for the output stream in question, i.e. your CoyoteOutputStream object signature. If you want to avoid this, don't return it.

Jersey HTTP POST method corrupting non-text files

I have a HTTP POST method that works fine if I upload text files. But if I try to upload a word document, pdf, zip, gzip, etc... the files that are uploaded get corrupted in the process. I'm using Postman to send the request. I do a "POST" method, enter the url, add headers (tried all sorts of headers and it really does not change anything so now I don't have any entered), and then on the body I select "formdata" and select the file. I really just need to fix this to be able to support files that end in .csv.gz and .csv. Currently, csv is fine but the .csv.gz is the type that is corrupting. I tried other non-text files as well just to see what happens and they corrupt too. I cannot figure out if there is some encoding, filter, etc... that is causing this to happen that I can remove or some setting I need to apply. Or if there is some other way to handle this with jersey so the non-text files stay the same as the original file.
My application is running Spring v1.5.3 and Jersey 2.25.
#Override
public Response uploadTopicFile(String topic, FormDataMultiPart formDataMultipart) throws Exception {
List<BodyPart> bodyParts = formDataMultipart.getBodyParts();
// Getting the body of the request (should be a file)
for (BodyPart bodyPart : bodyParts) {
String fileName = bodyPart.getContentDisposition().getFileName();
InputStream fileInputStream = bodyPart.getEntityAs(InputStream.class);
String uploadedFileLocation = env.getProperty("temp.upload.path") + File.separator + fileName;
this.saveFile(fileInputStream, uploadedFileLocation);
String output = "File uploaded to : " + uploadedFileLocation;
log.debug(output);
}
return Response.status(201).build();
}
private void saveFile(InputStream uploadedInputStream, String serverLocation) {
try {
// Create the output directory
Files.createDirectories(Paths.get(serverLocation).getParent());
// Get the output stream
OutputStream outputStream = new FileOutputStream(new File(serverLocation));
int read = 0;
byte[] bytes = new byte[1024];
// Loop through the stream
while ((read = uploadedInputStream.read(bytes)) != -1) {
// Output to file
outputStream.write(bytes, 0, read);
}
// Flush and close
outputStream.flush();
outputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
return;
}

There was a filter causing the corruption. Filter was updated and issue resolved.

Unexpected character encountered while parsing value when validating content as JSON in WOPI

I am currently implementing the WOPI with my application. Our domain is already whitelisted by Microsoft. While implementation I am currently facing two problems as mentioned below:
The exception is thrown when trying to validate content as JSON: 'Unexpected character encountered while parsing value.' I am sending my response "Value=application/octet-stream" but I don't understand why the server is trying to parse the stream as JSON.
After every new request coming from "iframe" is initiating a new session in the JAVA.
Here are more details:
My current URL is https://onenote.officeapps-df.live.com/hosting/WopiTestFrame.aspx?ui=en-US&rs=en-US&dchat=1&hid=26D7CA2A10F60A68720106BF599F84B9&&WOPISrc=https://domain/wopiEditor/files/73346e47-697b-11e6-a8bc-c26cd8f74b91/courses/independentConcepts/concept_adminGlo_5/assets/Setting url for static ip.docx&access_token=DEADBEEFDEADBEEFDEADBEEF&access_token_ttl=1532765580679
And My Java code is as following:
public void getFile(HttpServletRequest request, HttpServletResponse response, String name) {
Println.getInstance().log(request.getSession().getId() + "re" + request.getRequestURI());
InputStream fis = null;
OutputStream toClient = null;
try {
String path = getFilePath(request) + name;
File file = new File(path);
String filename = file.getName();
// XWPFDocument xDoc = new XWPFDocument(OPCPackage.open(fis));
fis = new BufferedInputStream(new FileInputStream(path));
byte[] buffer = new byte[fis.available()];
fis.read(buffer);
response.reset();
response.addHeader("Content-Disposition",
"attachment;filename=" + new String(filename.getBytes("utf-8"), "ISO-8859-1"));
response.addHeader("Content-Length", "" + file.length());
response.addHeader("Content-Type", "" + "application/octet-stream");
//Println.getInstance().log(file.length() + "l" + file);
toClient = new BufferedOutputStream(response.getOutputStream());
response.setContentType("application/octet-stream");
toClient.write(buffer);
toClient.flush();
} catch (IOException ex) {
ex.printStackTrace();
} finally {
try {
fis.close();
toClient.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
The test frame image is attached

The error you are seeing is on the CheckFileInfo request which is supposed to be returned as JSON. The Java snippit that you provided is for the getFile request which is a separate call that is made from the Office Online server. You should look over https://wopi.readthedocs.io/projects/wopirest/en/latest/ for how to write your implementation.

One thought is maybe you need to set the Content-Type header more specifically instead of the application/octet-stream you are sending?
Also there are quite a lot of other header values you are supposed to be returning, some of them may matter as well:
https://wopi.readthedocs.io/projects/wopirest/en/latest/common_headers.html#common-headers

Zip file getting downloaded without .zip extension in Chrome through Java

I am trying to download a zip file from a fixed location present in server.
In my Rest method , I am just passing the file name from client (browser) .
(Please see below code ).
In my Rest method I am sending the zip file to the client.
The file gets downloaded on the browser without any issue.
My Issue is that the zip file gets downloaded on browser without .zip extension.
#RequestMapping(value = "/zip/{filePath}", method = RequestMethod.GET)
public #ResponseBody void downloadZip(#PathVariable("filePath") String filePath, HttpServletRequest request, HttpServletResponse response) throws IOException {
ServletContext context = request.getServletContext();
File downloadFile = new File(filePath);
FileInputStream inputStream = new FileInputStream(downloadFile);
// get output stream of the response
OutputStream outStream = response.getOutputStream();
byte[] buffer = new byte[(int) downloadFile.length()];
int bytesRead = -1;
// write bytes read from the input stream into the output stream
while ((bytesRead = inputStream.read(buffer)) != -1) {
outStream.write(buffer, 0, bytesRead);
}
// get MIME type of the file
String mimeType = context.getMimeType(fullPath);
if (mimeType == null) {
// set to binary type if MIME mapping not found
mimeType = "application/octet-stream";
}
System.out.println("MIME type: " + mimeType);
// set content attributes for the response
response.setContentType(mimeType);
response.setContentLength((int) downloadFile.length());
response.setHeader("Content-Disposition",
String.format("attachment; filename=\"%s\"", downloadFile.getName()));
logger.error("Filename = " + downloadFile.getName());
inputStream.close();
outStream.close();
}
PS: The file gets downloaded on some machine with ZIP and in some machine without ZIP. I have tested only on chrome (as per client requirement).
I think, there is an issue with the Chrome settings which I need to look upon (just a guess).
Can someone help upon this?
Thanks in advance....

Change the order between setting the response headers and shoving the file down the output stream - after all, the headers need to leave first.
[Edited]
"Why setting HttpServletResponse in starting effects the code."
Well, simple: the client is supposed to receive instructions of what to do with the payload by interpreting the HTTP response headers. If those are not set in the beginning, sending those headers at the end of the transmission comes too late. And this assumes the HttpServletResponse will actually send those headers when invoked with setHeader, which is a big assumption - I suspect those headers will not actually be sent after calling response.getOutputStream - it is unlikely the response will buffer the entire payload to wait for the caller to specify those headers.

http response getting printed in browser if "Content-type" and "content-disposition" are set after writing in http "response" outputstream

I have a use-case where I have to set "Content-type" and "content-disposition" after writing in http response outputstream instead of downloading as a file. Following sample code depicts the case :-
#Context
HttpServletResponse response;
#GET
#Produces(MediaType.TEXT_PLAIN)
public String downloadFile() throws IOException {
File file = new File("/var/tmp/input.txt");
FileInputStream fs = new FileInputStream(file);
copyStream(fs, response.getOutputStream());
response.setContentType("text/csv");
response.setHeader("Content-Disposition","attachment;filename=\"" + "ts.csv" + "\"");
return "";
}
When I give a small input (input.txt file), my browser gives me option to download it but when the input is large, it prints the file content directly in the browser tab.
Any pointers what I can do such that it gives a file downoad option for large input as well?

As per documentation at ServletResponse.setContentType:
Sets the content type of the response being sent to the client, if the response has not been committed yet.
And, as per documentation at ServletResponse.getWriter:
Returns a PrintWriter object that can send character text to the client.
In your coding, you are writing content to the response object before setting the content-type.
You should have not written into the response output stream, for your custom content type to work.
Change your code:
copyStream(fs, response.getOutputStream());
response.setContentType( "text/csv" );
response.setHeader( "Content-Disposition",
"attachment;filename=\"" + "ts.csv" + "\"" );
To:
response.setContentType( "text/csv" );
response.setHeader( "Content-Disposition",
"attachment;filename=\"" + "ts.csv" + "\"" );
copyStream(fs, response.getOutputStream());