golang常用库之gorilla/mux-http路由库使用详解

一：golang自带路由介绍

golang自带路由库 http.ServerMux ，实际上是一个 map[string]Handler，是请求的url路径和该url路径对于的一个处理函数的映射关系。这个实现比较简单，有一些缺点：

不支持参数设定，例如/user/:uid 这种泛型类型匹配无法很友好的支持REST模式，无法限制访问方法（POST，GET等）也不支持正则

二：gorilla/mux路由

github地址：https://github.com/gorilla/mux

http://www.gorillatoolkit.org/pkg/mux

https://github.com/gorilla/mux#examples

上面所指出来的glang自带路由的缺点，gorilla/mux 都具备，而且还兼容 http.ServerMux。除了支持路径正则，命名路由，还支持中间件等等功能。所以mux是一个短小精悍，功能很全的路由。

1. 普通路由

示例 demo1.go

package main



import (

	"fmt"

	"github.com/gorilla/mux"

	"net/http"

)



func main() {

	r := mux.NewRouter()

	//普通路由

	r.HandleFunc("/", IndexHandler)

	r.HandleFunc("/products", ProductsHandler)



	http.ListenAndServe(":8080", r)

}



func IndexHandler(w http.ResponseWriter, r *http.Request) {

	w.WriteHeader(http.StatusOK)

	fmt.Fprintf(w, "hello world")

}



func ProductsHandler(w http.ResponseWriter, r *http.Request) {

	w.WriteHeader(http.StatusOK)

	fmt.Fprintf(w, "hello, Products")

}

上面mux的普通路由是不是似曾相识，跟golang标准库用法一样

在浏览器访问：http://localhost:8080/products

输出：hello, Products

2. 参数路由

参数路由，可以是普通路由，还可以是正则匹配

示例 demo2.go：

package main



import (

	"net/http"



	"fmt"



	"github.com/gorilla/mux"

)



//路由参数

func main() {

	r := mux.NewRouter()

	//1. 普通路由参数

	// r.HandleFunc("/articles/{title}", TitleHandler)



	//2. 正则路由参数，下面例子中限制为英文字母

	r.HandleFunc("/articles/{title:[a-z]+}", TitleHandler)



	http.ListenAndServe(":8080", r)

}



//https://github.com/gorilla/mux#examples

func TitleHandler(w http.ResponseWriter, r *http.Request) {

	vars := mux.Vars(r) // 获取参数

	w.WriteHeader(http.StatusOK)

	fmt.Fprintf(w, "title: %v\n", vars["title"])

}

第1个普通路由参数，就是啥参数都可以，不管是字母，数字，还是中文等

第2个正则路由参数，限制了只能是英文字母，否则会报 404 page not found

3. 路由匹配Matching Routes

https://github.com/gorilla/mux#matching-routes

我们也可以限制路由或者子路由。

3.1 匹配host

r := mux.NewRouter()

//只匹配 www.example.com

r.Host("www.example.com")

// 动态匹配子路由

r.Host("{subdomain:[a-z]+}.example.com")

3.2 更多的一些其他匹配

见下面的更多匹配的例子：

r := mux.NewRouter()



r.PathPrefix("/products/") //前缀匹配

r.Methods("GET", "POST") //请求方法匹配

r.Schemes("https") //schemes

r.Headers("X-Requested-With", "XMLHttpRequest") //header 匹配

r.Queries("key", "value") //query的值匹配



// 用户自定义方法 匹配

r.MatcherFunc(func(r *http.Request, rm *RouteMatch) bool { 

 return r.ProtoMajor == 0

})

把上面的联合起来在一个单独的route里

r.HandleFunc("/products", ProductsHandler).

 Host("www.example.com").

 Methods("GET").

 Schemes("http")

3.3 子路由匹配

Subrouter()可以设置子路由

r := mux.NewRouter()

s := r.Host("www.example.com").Subrouter()



s.HandleFunc("/products/", ProductsHandler)

s.HandleFunc("/products/{key}", ProductHandler)

s.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler)

3.4 多个路由匹配的顺序

如果有多个路由添加到路由器里面，那么匹配顺序是怎么样？按照添加的先后顺序匹配。比如有2个路由都匹配了，那么优先匹配第一个路由。

r := mux.NewRouter()

r.HandleFunc("/specific", specificHandler)

r.PathPrefix("/").Handler(catchAllHandler)

4. 设置路由前缀

PathPrefix()设置路由前缀

r := mux.NewRouter()



//PathPrefix() 可以设置路由前缀

product := r.PathPrefix("/products").HandleFunc("/", ProductsHandler)

路由前缀一般情况下不会单独使用，而是和子路由结合起来用，实现路由分组

5. 分组路由

可以根据前面的子路由和路由前缀的功能，综合运用就可以设置分组路由了

实例：grouprouter.go

package main



import (

	"fmt"

	"github.com/gorilla/mux"

	"net/http"

)



//子路由, 分组路由

func main() {

	r := mux.NewRouter()



	//PathPrefix() 可以设置路由前缀，设置路由前缀为products

	products := r.PathPrefix("/products").Subrouter()

	//"http://localhost:8080/products/", 最后面的斜线一定要，不然路由不正确，页面出现404

	products.HandleFunc("/", ProductsHandler)

	//"http://localhost:8080/products/{key}"

	products.HandleFunc("/{key}", ProductHandler)



	users := r.PathPrefix("/users").Subrouter()

	// "/users"

	users.HandleFunc("/", UsersHandler)

	// "/users/id/参数/name/参数"

	users.HandleFunc("/id/{id}/name/{name}", UserHandler)



	http.ListenAndServe(":8080", r)

}



func ProductsHandler(w http.ResponseWriter, r *http.Request) {

	w.WriteHeader(http.StatusOK)

	fmt.Fprintf(w, "%s", "products")

}



func ProductHandler(w http.ResponseWriter, r *http.Request) {

	vars := mux.Vars(r) //获取路由的值

	fmt.Fprintf(w, "key: %s", vars["key"])

}



func UsersHandler(w http.ResponseWriter, r *http.Request) {

	fmt.Fprintf(w, " %s \r\n", "users handler")

}



func UserHandler(w http.ResponseWriter, r *http.Request) {

	vars := mux.Vars(r) //获取值

	id := vars["id"]

	name := vars["name"]

	fmt.Fprintf(w, "id: %s, name: %s \r\n", id, name)

}

6. 路由中间件

https://github.com/gorilla/mux#middleware

Mux middlewares are defined using the de facto standard type: 在mux中路由中间件的定义

type MiddlewareFunc func(http.Handler) http.Handler

示例1：middleware1.go

package main



import (

	"fmt"

	"net/http"



	"github.com/gorilla/mux"

)



func main() {

	r := mux.NewRouter()

	r.HandleFunc("/", handler)



	r.Use(loggingMiddleware)



	http.ListenAndServe(":8080", r)

}



func loggingMiddleware(next http.Handler) http.Handler {

	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {

		//Do stuff here

		fmt.Println(r.RequestURI)

		fmt.Fprintf(w, "%s\r\n", r.URL)

		// Call the next handler, which can be another middleware in the chain, or the final handler.

		next.ServeHTTP(w, r)

	})

}



func handler(w http.ResponseWriter, r *http.Request) {

	w.Write([]byte("handle middleware"))

	fmt.Println("print handler")

}

示例2：middleware2.go

在来看一个复杂点的例子：

package main



import (

	"fmt"

	"net/http"

	"strings"



	"github.com/gorilla/mux"

)



type authMiddleware struct {

	tokenUsers map[string]string

}



func (amw *authMiddleware) Populate() {

	amw.tokenUsers = make(map[string]string)

	amw.tokenUsers["000"] = "user0"

	amw.tokenUsers["aaa"] = "userA"

	amw.tokenUsers["05ft"] = "randomUser"

	amw.tokenUsers["deadbeef"] = "user0"

}



func (amw *authMiddleware) Middleware(next http.Handler) http.Handler {

	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {

		token := strings.Trim(r.Header.Get("X-Session-Token"), " ")

		if token == "" {

			fmt.Fprintf(w, "token is error \r\n")

		}



		if user, found := amw.tokenUsers[token]; found {

			//we found the token in out map

			fmt.Printf("Authenticated user: %s\n", user)

			fmt.Fprintf(w, "Authenticated user: %s\n", user)

			// Pass down the request to the next middleware (or final handler)

			next.ServeHTTP(w, r)

		} else {

			// Write an error and stop the handler chain

			http.Error(w, "Forbidden", http.StatusForbidden)

		}

	})

}



func main() {

	r := mux.NewRouter()

	r.HandleFunc("/", handler)



	amw := authMiddleware{}

	amw.Populate()



	r.Use(amw.Middleware)



	http.ListenAndServe(":8080", r)

}



func handler(w http.ResponseWriter, r *http.Request) {

	w.Write([]byte("handler"))

}

用 insomnia 软件测试，如下图：

X-Session-Token=aaa 返回时正确





那-Session-Token=aaaa 呢

返回 403 了

7. Walking Routes 遍历注册的所有路由

package main



import (

	"fmt"

	"net/http"

	"strings"



	"github.com/gorilla/mux"

)



func handler(w http.ResponseWriter, r *http.Request) {

	return

}



//https://github.com/gorilla/mux#walking-routes

func main() {

	r := mux.NewRouter()

	r.HandleFunc("/", handler)

	r.HandleFunc("/products", handler).Methods("POST")

	r.HandleFunc("/articles", handler).Methods("GET")

	r.HandleFunc("/articles/{id}", handler).Methods("GET", "PUT")

	r.HandleFunc("/authors", handler).Queries("surname", "{surname}")

	err := r.Walk(func(route *mux.Route, router *mux.Router, ancestors []*mux.Route) error {

		pathTemplate, err := route.GetPathTemplate()

		if err == nil {

			fmt.Println("ROUTE:", pathTemplate)

		}

		pathRegexp, err := route.GetPathRegexp()

		if err == nil {

			fmt.Println("Path regexp:", pathRegexp)

		}

		queriesTemplates, err := route.GetQueriesTemplates()

		if err == nil {

			fmt.Println("Queries templates:", strings.Join(queriesTemplates, ","))

		}

		queriesRegexps, err := route.GetQueriesRegexp()

		if err == nil {

			fmt.Println("Queries regexps:", strings.Join(queriesRegexps, ","))

		}

		methods, err := route.GetMethods()

		if err == nil {

			fmt.Println("Methods:", strings.Join(methods, ","))

		}

		fmt.Println()

		return nil

	})



	if err != nil {

		fmt.Println(err)

	}



	http.Handle("/", r)

	http.ListenAndServe(":8080", nil)

}

8. 其他示例

请求方法限制

demo3.go:

package main



import (

	"fmt"

	"github.com/gorilla/mux"

	"net/http"

)



// 请求方法的限制, Methods()

func main() {

	r := mux.NewRouter()



	r.HandleFunc("/products", ProductsHandler).Methods("GET", "POST")



	r.Handle("/products/{id}", &ProductsIdHandler{}).Methods("GET")

	http.ListenAndServe(":8080", r)

}



func ProductsHandler(w http.ResponseWriter, r *http.Request) {

	w.WriteHeader(http.StatusOK)

	fmt.Fprintf(w, "hello, products! ")

}



type ProductsIdHandler struct{}



func (handler *ProductsIdHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {

	vars := mux.Vars(r)

	w.WriteHeader(http.StatusOK)

	fmt.Fprintf(w, "products id: %s", vars["id"])

}

请求头限制

在路由定义中可以通过Headers() 方法来限制设置请求头的匹配。

demo4.go

package main



import (

	"fmt"

	"net/http"



	"github.com/gorilla/mux"

)



// 请求头的限制，用Headers() 来限制

func main() {

	r := mux.NewRouter()



	r.HandleFunc("/products", func(w http.ResponseWriter, r *http.Request) {

		header := "Request-Limit-Test"

		fmt.Fprintf(w, "contain headers: %s = %s \n", header, r.Header[header])

	}).Headers("Request-Limit-Test", "RequestLimitTest").Methods("POST")



	http.ListenAndServe(":8080", r)

}

自定义匹配规

用 MatcherFunc() 来自定义规则

示例 demo5.go：**

package main



import (

	"fmt"

	"net/http"



	"github.com/gorilla/mux"

)



//自定义匹配 MatcherFunc()

func main() {

	r := mux.NewRouter()



	r.HandleFunc("/products/matcher", func(w http.ResponseWriter, r *http.Request) {

		fmt.Fprintf(w, "FormValue: %s ", r.FormValue("func"))

	}).MatcherFunc(func(req *http.Request, match *mux.RouteMatch) bool {

		b := false

		if req.FormValue("func") == "matcherfunc" {

			b = true

		}

		return b

	})



	http.ListenAndServe(":8080", r)

}

在浏览器中：http://127.0.0.1:8080/products/matcher?func=matcherfunc

输出：FormValue: matcherfunc

命名路由Registered URLs

namerouter.go

package main



import (

	"fmt"

	"github.com/gorilla/mux"

	// "log"

	"net/http"

)



// 命名路由 Name(), 获取路由URL， URL()

func main() {

	r := mux.NewRouter()

	r.HandleFunc("/products/{category}/{id:[0-9]+}", ProductHandler).Name("product")



	//获取路由的URL

	url1, err := r.Get("product").URL()

	fmt.Println(err) //error: mux: number of parameters must be multiple of 2, got [/]

	if err == nil {

		fmt.Println("get URL: \r\n", url1)

	}



	//获取路由的url后，也可以拼装你需要的URL

	url2, err := r.Get("product").URL("category", "tech", "id", "13")

	if err == nil {

		fmt.Println("new url: ", url2) //new url: /products/tech/13

	}



	http.ListenAndServe(":8080", r)

}



func ProductHandler(w http.ResponseWriter, r *http.Request) {

	w.WriteHeader(http.StatusOK)

	vars := mux.Vars(r)



	fmt.Fprintf(w, "url: %s, category: %s, id: %s", r.URL, vars["category"], vars["id"])

	//浏览器： http://localhost:8080/products/id/23



	//output

	//url: /products/id/23, category: id, id: 23

}

根据命名的路由来获取路由URLr.Get("product").URL()

三：参考

https://github.com/gorilla/mux