Direct download of a blob from server

Question

I wrote a Restful webservice with MongoDB. This is my code :

@GET
@Path("/download/{id}/")
@Produces("application/epub")
public Response getImagefile(@PathParam("content") String content,
        @PathParam("id") String imageID) throws UnknownHostException, IOException {
    String urlContent = "D:\\NetbeansWorkspace\\Webservice\\web\\download\\image.jpg";
    GridFSDBFile findImage;
        DB db = getConnection().getDB(content);
        GridFS gfsImage = new GridFS(db, "image");
        findImage = gfsImage.findOne(new ObjectId(imageID));
        findImage.writeTo(urlContent);
        File file = new File(urlContent);
        ResponseBuilder response = Response.ok((Object) urlContent);
        response.header("Content-Disposition",
                "attachment; filename=" + "image.jpg");
        return response.build();

}

I am extracting an image from a server and providing a link to it for a download. This code does this not very efficiently by saving it to urlContent (my local file) first and then making it available for download. I would like to skip saving to urlContent part and provide a link which extracts and downloads a blob image directly from the server. How can I do it?

score 0 · Answer 1 · edited May 23 '17 at 12:30

0

This question has a good example on how to do it, although it is about pdf files (it shouldn't make any difference). In a nutshell, the service should return a StreamingOutput, which is basically a wrapper around an OutputStream.

In this answer there is an even more complete example, which uses the StreamingOutput as the entity of a Response.

edited May 23 '17 at 12:30

Community

1
1

answered Jul 03 '15 at 08:10

francesco foresti

2,004
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score 0 · Answer 2 · answered Jul 03 '15 at 09:34

FIXED

@GET
@Path("/download/{id}/")
@Produces("application/epub")
public Response getImagefile(@PathParam("content") String content,
        @PathParam("id") String imageID) throws UnknownHostException, IOException {

        GridFSDBFile findImage;
        DB db = getConnection().getDB(content);
        GridFS gfsImage = new GridFS(db, "image");
        findImage = gfsImage.findOne(new ObjectId(imageID));
        String filename = findImage.getFilename();
        ResponseBuilder response = Response.ok((Object) findImage.getInputStream());
        response.header("Content-Disposition",
                "attachment; filename=" + filename+".jpg");
        return response.build();

}

Direct download of a blob from server

2 Answers2