Golang解析、驗證、修改URL之Host、Port、Path

• URL解析驗證問題
  • net.ParseIP()只能解析不帶冒號以及端口號的IP4/IP6
    • ✔: 127.0.0.1、2001:db8::68
    • ✖: 127.0.0.1:8080、www.baidu.com
  • url.Parse()最好只用來解析標准URL，不能用來驗證URL的正確性

func main() {
	IP1 := "www.baidu.com"
	IP2 := "127.0.0.1"
	IP3 := "127.0.0.1:8080"
	parsedIP1 := net.ParseIP(IP1)
	parsedIP2 := net.ParseIP(IP2)
	parsedIP3 := net.ParseIP(IP3)
	fmt.Println("net.ParseIP: ", parsedIP1, parsedIP2, parsedIP3)

	fmt.Println()

	Url1 := "127.0.0"
	Url2 := "abc"
	Url3 := "127.0.0.1:8080"
	Url4 := "http://127.0.0.1:8080/url"

	parsedUrl1, err := url.Parse(Url1)
	if err != nil {
		fmt.Println("Error: ", err)
	}
	parsedUrl2, err := url.Parse(Url2)
	if err != nil {
		fmt.Println("Error: ", err)
	}
	parsedUrl3, err := url.Parse(Url3)
	if err != nil {
		fmt.Println("Error: ", err)
	}
	parsedUrl4, err := url.Parse(Url4)
	if err != nil {
		fmt.Println("Error: ", err)
	}
	fmt.Println("1: ", parsedUrl1, "2: ", parsedUrl2, "3: ", parsedUrl3, "4: ", parsedUrl4)
}
/*
輸出結果：
net.ParseIP:  <nil> 127.0.0.1 <nil>

Error:  parse 127.0.0.1:8080: first path segment in URL cannot contain colon
1:  127.0.0 2:  abc 3:  <nil> 4:  http://127.0.0.1:8080/url

*/

• 正確的URL驗證方式

  • go get github.com/asaskevich/govalidator
  • govalidator.IsURL()

• 獲取並修改URL之Host、Port、Path

func main() {
	rawUrl := "http://127.0.0.1:8080/url/123"
	changeHost := "192.168.1.1"

	newUrl, _ := url.Parse(rawUrl)

	// Host
	newUrlHost := newUrl.Hostname()
	// Port
	newUrlPort := newUrl.Port()
	// Path
	newUrlPath := newUrl.Path
	// URL類型轉string
	stringUrl := newUrl.String()
	// 修改URl Host
	newUrl.Host = changeHost + ":" + newUrl.Port()

	fmt.Println(newUrlHost, newUrlPort, newUrlPath, stringUrl, newUrl)
}

其他相關方法:

• Host、Port
  • net.SplitHostPort() ==> Host、Port、error
  • u := strings.Split(url, ":") ==> Host := u[0]
• Path
  • url := http://www.a.com/123 ==> base := path.Base(url)
  • fmt.Println(base) ==> 123
    
    

以上結合可完成關於Golang操作URL的大部分問題