如何使Go HTTP客户端不自动关注重定向？

4 回答

• 4

  要使用不遵循重定向的Basic Auth发出请求，请使用接受* Request的RoundTrip函数

  这段代码

  package main
  
  import (
      "fmt"
      "io/ioutil"
      "net/http"
      "os"
  )
  
  func main() {
      var DefaultTransport http.RoundTripper = &http.Transport{}
  
      req, _ := http.NewRequest("GET", "http://httpbin.org/headers", nil)
      req.SetBasicAuth("user", "password")
  
      resp, _ := DefaultTransport.RoundTrip(req)
      defer resp.Body.Close()
      contents, err := ioutil.ReadAll(resp.Body)
      if err != nil {
          fmt.Printf("%s", err)
          os.Exit(1)
      }
      fmt.Printf("%s\n", string(contents))
  }
  

  输出

  {
    "headers": {
      "Accept-Encoding": "gzip", 
      "Authorization": "Basic dXNlcjpwYXNzd29yZA==", 
      "Connection": "close", 
      "Host": "httpbin.org", 
      "User-Agent": "Go 1.1 package http", 
      "X-Request-Id": "45b512f1-22e9-4e49-8acb-2f017e0a4e35"
    }
  }
  

  回复于 2024-04-24T00:33:10+08:00
• 11

  现在有一个更简单的解决方案：

  client: &http.Client{
      CheckRedirect: func(req *http.Request, via []*http.Request) error {
          return http.ErrUseLastResponse
      },
  }
  

  这样， http 包自动知道："Ah, I shouldn't follow any redirects"，但不会抛出任何错误 . 从源代码中的注释：

  作为一种特殊情况，如果CheckRedirect返回ErrUseLastResponse，则返回最近的响应，其主体未闭合，并返回nil错误 .

  回复于 2024-04-24T00:33:10+08:00
• 77

  这是可能的，但解决方案稍微扭转了问题 . 这是一个写成golang测试的示例 .

  package redirects
  
  import (
      "github.com/codegangsta/martini-contrib/auth"
      "github.com/go-martini/martini"
      "net/http"
      "net/http/httptest"
      "testing"
  )
  
  func TestBasicAuthRedirect(t *testing.T) {
      // Start a test server
      server := setupBasicAuthServer()
      defer server.Close()
  
      // Set up the HTTP request
      req, err := http.NewRequest("GET", server.URL+"/redirect", nil)
      req.SetBasicAuth("username", "password")
      if err != nil {
          t.Fatal(err)
      }
  
      transport := http.Transport{}
      resp, err := transport.RoundTrip(req)
      if err != nil {
          t.Fatal(err)
      }
      // Check if you received the status codes you expect. There may
      // status codes other than 200 which are acceptable.
      if resp.StatusCode != 200 && resp.StatusCode != 302 {
          t.Fatal("Failed with status", resp.Status)
      }
  
      t.Log(resp.Header.Get("Location"))
  }
  
  
  // Create an HTTP server that protects a URL using Basic Auth
  func setupBasicAuthServer() *httptest.Server {
      m := martini.Classic()
      m.Use(auth.Basic("username", "password"))
      m.Get("/ping", func() string { return "pong" })
      m.Get("/redirect", func(w http.ResponseWriter, r *http.Request) {
          http.Redirect(w, r, "/ping", 302)
      })
      server := httptest.NewServer(m)
      return server
  }
  

  您应该能够将上面的代码放入它自己的名为“redirects”的包中，并在使用后获取所需的依赖项后运行它

  mkdir redirects
  cd redirects
  # Add the above code to a file with an _test.go suffix
  go get github.com/codegangsta/martini-contrib/auth
  go get github.com/go-martini/martini
  go test -v
  

  希望这可以帮助！

  回复于 2024-04-24T00:33:10+08:00
• 6

  另一种选择，使用客户端本身，没有RoundTrip：

  // create a custom error to know if a redirect happened
  var RedirectAttemptedError = errors.New("redirect")
  
  client := &http.Client{}
  // return the error, so client won't attempt redirects
  client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
          return RedirectAttemptedError
  }
  // Work with the client...
  resp, err := client.Head(urlToAccess)
  
  // test if we got the custom error
  if urlError, ok := err.(*url.Error); ok && urlError.Err == RedirectAttemptedError{
          err = nil   
  }
  

  UPDATE: 此解决方案适用于<1.7

  回复于 2024-04-24T00:33:10+08:00