Displaying file: MessageBodyReader not found for media type=application/octet-stream - web-services

Question

My requirement is that I should display a file using RESTFul services. Here how I proceeded:
Server:
#GET
#Path("/{name}")
#Produces(MediaType.APPLICATION_OCTET_STREAM)
public Response getFile {
...
return Response.ok(inputStream).header("Content-Disposition", "attachment; filename=" + fileName).build();
Client:
final WebTarget target = createRestClient("path/" + fileName, new HashMap<String, Object>());
return target.request(MediaType.APPLICATION_OCTET_STREAM).get().readEntity(Part.class);
When I run it, I've got this error:
MessageBodyReader not found for media type=application/octet-stream, type=interface javax.servlet.http.Part, genericType=interface javax.servlet.http.Part.
Do you have any idea where did this come from?
Thanks.

Answer 1

javax.servlet.http.Part should be used to obtain upload multipart data, and is created by the servlet container, which you obtain from a HttpServletRequest. It should not be used in this way. Beside the data is not even multipart.
Instead, you can simply get the InputStream from the from the Response and the Content-Dispostion get explicitly from the header. Something like
Response response = target.request()
.accept(MediaType.APPLICATION_OCTET_STREAM)
.get();
// get InputStream
InputStream is = response.readEntity(InputStream.class);
// get Content-Disposition header
String contentDisposition = (String)response
.getHeaderString(HttpHeaders.CONTENT_DISPOSITION);
// get filename
contentDisposition = contentDisposition
.substring(contentDisposition.indexOf("filename=") + "filename".length() + 1);
System.out.println(contentDisposition);