本文為轉載，原文：Golang 第三方庫學習 · mux
Golang
介紹
mux 是一個用來執行http請求的路由和分發的第三方擴展包。
mux 其名稱來源于HTTP request multiplexer，類似于官方包http.ServeMux，mux.Router將會定義一個路由列表，其中每一個路由都會定義對應的請求url，及其處理方法。
源碼
第三方庫源碼：
https://github.com/gorilla/mux
本文源碼：
https://github.com/Chain-Zhang/third-lib
安裝
go get -u github.com/gorilla/mux
使用
添加包引用：
"github.com/gorilla/mux"
常用方法介紹
初始化路由
r := mux.NewRouter()
路由注冊
最簡單的路由注冊：
r.HandleFunc("/", HomeHandler)
其中代碼中的第一個參數為請求url，第二個參數為請求的處理函數，該函數可簡單的定義為以下代碼：
func HomeHandler(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusOK)
fmt.Fprintf(w, "this is home")
}
帶有變量的url路由注冊：
其中參數可使用正則表達式匹配
r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler)
指定Host：
r.Host("www.example.com")
指定http方法：
r.Methods("GET", "POST")
指定URL安全策略：
r.Schemes("https")
增加URL前綴：
r.PathPrefix("/products/")
添加請求頭：
r.Headers("X-Requested-With", "XMLHttpRequest")
添加請求參數：
r.Queries("key", "value")
組合使用：
r.HandleFunc("/products", ProductsHandler).
Host("www.example.com").
Methods("GET").
Schemes("http")
子路由的使用：
r := mux.NewRouter()
s := r.PathPrefix("/products").Subrouter()
// "/products/"
s.HandleFunc("/", ProductsHandler)
// "/products/{key}/"
s.HandleFunc("/{key}/", ProductHandler)
// "/products/{key}/details"
s.HandleFunc("/{key}/details", ProductDetailsHandler)
定義路由別名：
r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler).Name("article")
靜態文件路由：
flag.StringVar(&dir, "dir", ".", "the directory to serve files from. Defaults to the current dir")
flag.Parse()
r := mux.NewRouter()
// This will serve files under http://localhost:8000/static/<filename>
r.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.Dir(dir))))
生成已注冊的URL:
生成已注冊的url需要用到路由的別名，代碼如下：
url, err := r.Get("router_name").URL("key1", "val1", "key2", "val2")
例如：
r := mux.NewRouter()
r.Host("{subdomain}.domain.com").
Path("/articles/{category}/{id:[0-9]+}").
Queries("filter", "{filter}").
HandlerFunc(ArticleHandler).
Name("article")
// url.String() will be "http://news.domain.com/articles/technology/42?filter=gorilla"
url, err := r.Get("article").URL("subdomain", "news",
"category", "technology",
"id", "42",
"filter", "gorilla")
Walk方法：
walk方法可以遍歷訪問所有已注冊的路由，例如以下代碼：
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)
}
Middleware 中間件
mux同樣也支持為路由添加中間件。
最簡單的中間件定義：
func loggingMiddleware(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// Do stuff here
log.Println(r.RequestURI)
// Call the next handler, which can be another middleware in the chain, or the final handler.
next.ServeHTTP(w, r)
})
}
中間件使用：
r := mux.NewRouter()
r.HandleFunc("/", handler)
r.Use(loggingMiddleware)
綜合示例
package th_mux
import(
"strings"
"flag"
"fmt"
"net/http"
"github.com/gorilla/mux"
)
func Run(){
var dir string
flag.StringVar(&dir, "dir", ".", "the directory to serve files from. Defaults to the current dir")
flag.Parse()
// 初始化Router
r := mux.NewRouter()
// 靜態文件路由
r.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.Dir(dir))))
// 普通路由
r.HandleFunc("/", HomeHandler)
// 指定host
r.HandleFunc("/host", HostHandler).Host("localhost")
// 帶變量的url路由
r.HandleFunc("/users/{id}", GetUserHandler).Methods("Get").Name("user")
url, _ := r.Get("user").URL("id", "5")
fmt.Println("user url: ", url.String())
// 遍歷已注冊的路由
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
})
r.Use(TestMiddleware)
http.ListenAndServe(":3000", r)
}
func HomeHandler(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusOK)
fmt.Fprintf(w, "this is home")
}
func HostHandler(w http.ResponseWriter, r *http.Request){
w.WriteHeader(http.StatusOK)
fmt.Fprintf(w, "the host is localhost")
}
func GetUserHandler(w http.ResponseWriter, r *http.Request){
vars := mux.Vars(r)
w.WriteHeader(http.StatusOK)
fmt.Fprint(w, "this is get user, and the user id is ", vars["id"])
}
func TestMiddleware(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// Do stuff here
fmt.Println("middleware print: ", r.RequestURI)
// Call the next handler, which can be another middleware in the chain, or the final handler.
next.ServeHTTP(w, r)
})
}
運行結果截圖
剛執行時的注冊打?。?br>
注冊
依次在瀏覽器中輸入以下地址測試，查看結果：
http://localhost:3000/
http://localhost:3000/host
http://127.0.0.1:3000/host
http://localhost:3000/users/5
完
轉載請注明出處：Golang 第三方庫學習 · mux
