How to Send Chunked HTTP Responses from a Go Server?

Send a Chunked HTTP Response from a Go Server

Solution:

To send chunked HTTP responses from a Go server and receive them in real time, it's necessary to invoke Flusher.Flush() after writing each data chunk. This triggers the "chunked" encoding and immediately sends the chunk to the client. Here's an example of how to implement this:

package main

import (
    "fmt"
    "io"
    "log"
    "net/http"
    "time"
)

func main() {
    http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        flusher, ok := w.(http.Flusher)
        if !ok {
            panic("expected http.ResponseWriter to be an http.Flusher")
        }
        w.Header().Set("X-Content-Type-Options", "nosniff")
        for i := 1; i <= 10; i++ {
            fmt.Fprintf(w, "Chunk #%d\n", i)
            flusher.Flush() // Trigger "chunked" encoding and send a chunk...
            time.Sleep(500 * time.Millisecond)
        }
    })

    log.Print("Listening on localhost:8080")
    log.Fatal(http.ListenAndServe(":8080", nil))
}

Verification:

Using telnet, you can connect to the server and witness the chunked response being delivered:

$ telnet localhost 8080
Trying ::1...
Connected to localhost.
Escape character is '^]'.
GET / HTTP/1.1

HTTP/1.1 200 OK
Date: Tue, 02 Jun 2015 18:16:38 GMT
Content-Type: text/plain; charset=utf-8
Transfer-Encoding: chunked

9
Chunk #1

9
Chunk #2

...

Additional Notes:

• It's worth researching whether http.ResponseWriters support concurrent access for simultaneous use by multiple goroutines.
• For more information on the "X-Content-Type-Options" header, consult this related question.

The above is the detailed content of How to Send Chunked HTTP Responses from a Go Server?. For more information, please follow other related articles on the PHP Chinese website!