first path segment in URL cannot contain colon

一:问题

func main(){    url,err:= url.Parse("127.0.0.1:8080")    if err!=nil{        fmt.Println(err)    }    fmt.Println(url.Host,url.Port())}

使用url.Parse()解析host是ip的url时(eg:127.0.0.1:8080),出现:first path segment in URL cannot contain colon

二:问题原因
报错的原因:url.Parse()里面调用的func parse(rawurl string, viaRequest bool) (*URL, error)这个函数报错

func parse(rawurl string, viaRequest bool) (*URL, error) {//.......if !strings.HasPrefix(rest, "/") {        if url.Scheme != "" {            // We consider rootless paths per RFC 3986 as opaque.            url.Opaque = rest            return url, nil        }        if viaRequest {            return nil, errors.New("invalid URI for request")        }        // Avoid confusion with malformed schemes, like cache_object:foo/bar.        // See golang.org/issue/16822.        //        // RFC 3986, §3.3:        // In addition, a URI reference (Section 4.1) may be a relative-path reference,        // in which case the first path segment cannot contain a colon (":") character.        //报错位置        colon := strings.Index(rest, ":")        slash := strings.Index(rest, "/")        if colon >= 0 && (slash < 0 || colon < slash) {            // First path segment has colon. Not allowed in relative URL.            return nil, errors.New("first path segment in URL cannot contain colon")        }    }    //............

三.处理方法
在func parse(rawurl string, viaRequest bool) (*URL, error)中:

if (url.Scheme != "" || !viaRequest && !strings.HasPrefix(rest, "///")) && strings.HasPrefix(rest, "//") {        var authority string        authority, rest = split(rest[2:], "/", false)        url.User, url.Host, err = parseAuthority(authority)        if err != nil {            return nil, err        }    }

看到这个部分,可以在127.0.0.1:8080前面加”//”解决(eg://127.0.0.1:8080)

四:补充

关于//host:port(this format is called the “network-path reference” from RFC 3986, section 4.2)
可以参考:https://stackoverflow.com/questions/3583103/network-path-reference-uri-scheme-relative-urls