Golang : How to stream file to client(browser) or write to http.ResponseWriter?
Problem :
You have a file - such as a PDF or MP3 file that you want to stream/download straight to your user's web browser(client). How to achieve that in Golang?
Solution :
Convert the files to buffer with bytes.NewBuffer()
function and write to http.ResponseWriter.
Code fragment taken from previous tutorial on how to generate PDF file.
func PDF(w http.ResponseWriter, r *http.Request) {
...
// grab the generated receipt.pdf file and stream it to browser
streamPDFbytes, err := ioutil.ReadFile("./receipt.pdf")
if err != nil {
fmt.Println(err)
os.Exit(1)
}
b := bytes.NewBuffer(streamPDFbytes)
// stream straight to client(browser)
w.Header().Set("Content-type", "application/pdf")
if _, err := b.WriteTo(w); err != nil { // <----- here!
fmt.Fprintf(w, "%s", err)
}
w.Write([]byte("PDF Generated"))
}
See also : Golang : Create PDF file from HTML file
By Adam Ng
IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.
Advertisement
Tutorials
+13.8k Golang : convert(cast) string to float value
+17.4k Golang : Linked list example
+14.5k Golang : Convert(cast) int to float example
+55.1k Golang : Unmarshal JSON from http response
+6.5k Elasticsearch : Shutdown a local node
+30.3k Get client IP Address in Go
+17.1k Golang : When to use init() function?
+12.1k Golang : md5 hash of a string
+6.8k Golang : Normalize email to prevent multiple signups example
+52.4k Golang : How to get struct field and value by name
+25.3k Golang : Generate MD5 checksum of a file
+28.9k Golang : Get first few and last few characters from string