golang常用库之gorilla/mux-http路由库使用详解

golang常用库：gorilla/mux-http路由库使用
golang常用库：配置文件解析库-viper使用
golang常用库：操作数据库的orm框架-gorm基本使用

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

来源：https://www.cnblogs.com/jiujuan/p/12768907.html