How to use regexp get url pattern in golang?

问题

How to use regular expression matching URL, which does decide to use the corresponding function processing

package main

import(
  "fmt"
  "net/http"
)

func main() {
  http.HandleFunc("/pattern", resolve)
  http.ListenAndServe(":8080", nil)
}

func resolve(w http.ResponseWriter, r * http.Request) {
  fmt.Println(r.URL.Host)
}

回答1:

http.HandleFunc() can not be used to register a pattern to match a regular expression. In short, the pattern specified at HandleFunc() can match a fixed, rooted path (like /favico.ico) or rooted subtrees (like /images/), longer patterns take precedence over shorter ones. You can find more details at the doc of the ServeMux type.

What you can do is register your handler to a rooted subtree which may be everything with the / pattern, and inside your handler you can do further regexp matching and routing.

For example:

func main() {
    http.HandleFunc("/", route) // Match everything
    http.ListenAndServe(":8080", nil)
}

var rNum = regexp.MustCompile(`\d`)  // Has digit(s)
var rAbc = regexp.MustCompile(`abc`) // Contains "abc"

func route(w http.ResponseWriter, r *http.Request) {
    switch {
    case rNum.MatchString(r.URL.Path):
        digits(w, r)
    case rAbc.MatchString(r.URL.Path):
        abc(w, r)
    default:
        w.Write([]byte("Unknown Pattern"))
    }
}

func digits(w http.ResponseWriter, r *http.Request) {
    w.Write([]byte("Has digits"))
}

func abc(w http.ResponseWriter, r *http.Request) {
    w.Write([]byte("Has abc"))
}

Or use an external library like Gorilla MUX.

回答2:

I use github.com/gorilla/mux package. So router looks like:

func main() {

    r := mux.NewRouter()

    r.HandleFunc("/{name:pattern}", handle)
    http.ListenAndServe(":8080", r)
}

where {name:pattern} could be simply {slug} (without pattern) or {id:[0-9]+} or combination of them /{category}/{id:[0-9]+}. And get them in handler func:

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

    params := mux.Vars(r)

    // for /{category}/{id:[0-9]+} pattern
    category := params["category"]
    id := params["id"]
}

run it and try curl http://localhost:8080/whatever/1

回答3:

Golang doesn't have built-in regex support for URL matching. And it's somewhat complicated to implement from scratch.

Maybe using a framework would be a better choice, such as beego or martin, etc.

来源：https://stackoverflow.com/questions/30474313/how-to-use-regexp-get-url-pattern-in-golang

标签

regex

http

url-routing