URL结构介绍以及使用golang解析URL

项目中想截取url中的域名部分，golang中提供了url.Parse方法解析url。但在解析之前，花一点时间全面了解url的结构。

URL(Uniform Resource Locator)统一资源定位符，就是由一串简单的文本字符组成。一条符合规范的URL对应的是服务器的一个特定的资源(如HTML页面，一张图片等)。

URL结构：

Scheme://Login:password@Address:port/path/to/resource?query_string#fragment

1. Scheme
   协议，如http,https,ftp等

2. Login:password@
   身份验证

3. Address
   服务器地址

4. Port
   服务器端口

5. /path/to/resource
   文件路径

6. ?query_string
   查询字符串

7. #fragment
   片段ID，如http页面中内部的标签

使用url.Parse方法解析url

package main

import (
	"log"
	"net/url"
)

func main() {
	site := "http://xiaoming:123456@www.example.com:8080/resource/level/next?file=got.rar×tamp=123432#temp"
	r, err := url.Parse(site)
	if err != nil {
		log.Fatalln("parse url [%v] failed!", site)
	}
	log.Printf("parse url value is [%v]", r)
	log.Printf("Schema is [%v]", r.Scheme)
	log.Printf("Login is [%v]", r.User.Username())
	if password, ok := r.User.Password(); ok {
		log.Printf("Password is [%v]", password)
	}
	log.Printf("Address is [%v]", r.Hostname())
	log.Printf("Port is [%v]", r.Port())
	log.Printf("Resource is [%v]", r.Path)
	log.Printf("Query is [%v]", r.Query())
	log.Printf("Fragment is [%v]", r.Fragment)
}

输出结果如下所示

2021/12/31 00:21:36 parse url value is [http://xiaoming:123456@www.example.com:8080/resource/level/next?file=got.rar×tamp=123432#temp]
2021/12/31 00:21:36 Schema is [http]
2021/12/31 00:21:36 Login is [xiaoming]
2021/12/31 00:21:36 Password is [123456]
2021/12/31 00:21:36 Address is [www.example.com]
2021/12/31 00:21:36 Port is [8080]
2021/12/31 00:21:36 Resource is [/resource/level/next]
2021/12/31 00:21:36 Query is [map[file:[got.rar] timestamp:[123432]]]
2021/12/31 00:21:36 Fragment is [temp]

参考资料：

1. https://www.cnblogs.com/be-saber/p/4734951.html