http.Request RequestURI字段在go中发出请求时

Question

我将请求从服务器转储到 []byte 并使用 ReadRequest 通过 Client.Do 方法发出请求。我收到一个错误:

http: Request.RequestURI can't be set in client requests.

你能解释一下为什么我会收到这个错误吗？

Answer 1

错误很明显:您不允许在执行客户端请求时设置 RequestURI。

在 http.Request.RequestURI 的文档中，它说(我强调):

RequestURI is the unmodified Request-URI of the
Request-Line (RFC 2616, Section 5.1) as sent by the client
to a server. Usually the URL field should be used instead.
It is an error to set this field in an HTTP client request.

设置它的原因是因为这是 ReadRequest 在解析请求流时所做的。

因此，如果要发送，则需要设置URL并清除RequestURI。经过尝试，我发现ReadRequest返回的请求中的URL对象并没有设置所有的信息，比如scheme和host。因此，您需要自己设置，或者使用 Parse 解析新的 URL。在 net/url 包中:

这是一些适合您的工作代码:

package main

import (
    "fmt"
    "strings"
    "bufio"
    "net/http"
    "net/url"
)

var rawRequest = `GET /pkg/net/http/ HTTP/1.1
Host: golang.org
Connection: close
User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X; de-de) AppleWebKit/523.10.3 (KHTML, like Gecko) Version/3.0.4 Safari/523.10
Accept-Encoding: gzip
Accept-Charset: ISO-8859-1,UTF-8;q=0.7,*;q=0.7
Cache-Control: no-cache
Accept-Language: de,en;q=0.7,en-us;q=0.3

`

func main() {
    b := bufio.NewReader(strings.NewReader(rawRequest))

    req, err := http.ReadRequest(b)
    if err != nil {
        panic(err)
    }

    // We can't have this set. And it only contains "/pkg/net/http/" anyway
    req.RequestURI = ""

    // Since the req.URL will not have all the information set,
    // such as protocol scheme and host, we create a new URL
    u, err := url.Parse("http://golang.org/pkg/net/http/")
    if err != nil {
        panic(err)
    }   
    req.URL = u

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }

    fmt.Printf("%#v\n", resp)
}

Playground

附言。 play.golang.org 会 panic ，因为我们没有做 http 请求的权限。