package main
import (
"fmt"
"net/http"
)
const addr = "localhost:7070"
type RedirecServer struct {
redirectCount int
}
func (s *RedirecServer) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
s.redirectCount++
fmt.Println("Received header: " + req.Header.Get("Known-redirects"))
http.Redirect(rw, req, fmt.Sprintf("/redirect%d", s.redirectCount), http.StatusTemporaryRedirect)
}
func main() {
s := http.Server{
Addr: addr,
Handler: &RedirecServer{0},
}
go s.ListenAndServe()
client := http.Client{}
redirectCount := 0
// If the count of redirects is reached
// than return error.
client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
fmt.Println("Redirected")
if redirectCount > 2 {
return fmt.Errorf("Too many redirects")
}
req.Header.Set("Known-redirects", fmt.Sprintf("%d", redirectCount))
redirectCount++
for _, prReq := range via {
fmt.Printf("Previous request: %v\n", prReq.URL)
}
return nil
}
_, err := client.Get("http://" + addr)
if err != nil {
panic(err)
}
}
/*
Received header:
Redirected
Previous request: http://localhost:7070
Received header: 0
Redirected
Previous request: http://localhost:7070
Previous request: http://localhost:7070/redirect1
Received header: 1
Redirected
Previous request: http://localhost:7070
Previous request: http://localhost:7070/redirect1
Previous request: http://localhost:7070/redirect2
Received header: 2
Redirected
panic: Get /redirect4: Too many redirects
goroutine 1 [running]:
main.main()
/Users/zrd/Desktop/go/go_path/src/go_web/xml.go:47 +0x238
*/