如何避免发送Content-Length标头

Question

对于流式http端点有没有办法避免发送长度？

  w.Header().Set("Content-Type", "image/jpeg")
  w.Header().Set("Transfer-Encoding", "chunked")
  w.Header().Del("Content-Length")

这是我回来的.

HTTP/1.1 200 OK
Content-Length: 0
Content-Type: image/jpeg
Date: Mon, 23 Jun 2014 10:00:59 GMT
Transfer-Encoding: chunked
Transfer-Encoding: chunked

服务器也会打印警告.

2014/06/23 06:04:03 http: WriteHeader called with both Transfer-Encoding of "chunked" and a Content-Length of 0

Answer 1

你不应该手动设置Transfer-Encoding.Go会为你做这件事,以及Content-Length.

curl,Go http客户端或任何标准http客户端将自动正确读取chunked或non-chunked http响应.

分块服务器的小例子:http://play.golang.org/p/miEV7URi8P

package main

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

// hello world, the web server
func HelloServer(w http.ResponseWriter, req *http.Request) {
        w.WriteHeader(200)
        for i := 0; i < 5; i++ {
                io.WriteString(w, "hello, world!\n")
                w.(http.Flusher).Flush()
        }
}

func main() {
        http.HandleFunc("/", HelloServer)
        err := http.ListenAndServe(":8080", nil)
        if err != nil {
                log.Fatal("ListenAndServe: ", err)
        }
}

在图像/ jpeg的情况下,您可以将分块决策委托给Go,或者从图像中手动发送N个字节,然后刷新.