没有方案抛出错误的错误

Question

I write a proxy and the problem is that some links on websites don't have scheme for example google:

<a class="ab_dropdownlnk" href="//www.google.com/support/websearch/?source=g&amp;hl=en">

I fetch the url via Client.Do()
How to resolve such urls in Go?

Answer 1

If there is no scheme then use a sensible default. For example,

package main

import (
    "fmt"
    "io/ioutil"
    "log"
    "net/http"
    "net/url"
)

func main() {
    href := "//www.google.com/support/websearch/?source=g&hl=en"
    url, err := url.Parse(href)
    if err != nil {
        log.Fatal(err)
    }
    if url.Scheme == "" {
        url.Scheme = "http"
    }
    req, err := http.NewRequest("GET", url.String(), nil)
    if err != nil {
        log.Fatal(err)
    }
    client := http.Client{}
    res, err := client.Do(req)
    if err != nil {
        log.Fatal(err)
    }
    websearch, err := ioutil.ReadAll(res.Body)
    res.Body.Close()
    if err != nil {
        log.Fatal(err)
    }
    fmt.Printf("%s
", websearch)
}