Go net/http server snippet

最小

package main

import (
    "net/http"
    "log"
    "fmt"
)

func hello(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "hello")
}

func main() {
    http.HandleFunc("/", hello)

    if err := http.ListenAndServe(":8080", nil); err != nil {
        log.Fatal(err)
    }
}

最小 (mux)

package main

import (
    "fmt"
    "log"
    "net/http"
)

func hello(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "hello")
}

func main() {
    mux := http.NewServeMux()
    mux.HandleFunc("/", hello)

    if err := http.ListenAndServe(":8080", mux); err != nil {
        log.Fatal(err)
    }
}

gorilla/mux

package main

import (
    "fmt"
    "log"
    "net/http"

    "github.com/gorilla/mux"
)

func hello(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "hello")
}

func main() {
    r := mux.NewRouter()
    r.HandleFunc("/", hello)

    if err := http.ListenAndServe(":8080", r); err != nil {
        log.Fatal(err)
    }
}

gorilla/mux Method指定

package main

import (
    "fmt"
    "log"
    "net/http"

    "github.com/gorilla/mux"
)

func hello(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "hello")
}

func main() {
    r := mux.NewRouter()
    r.Methods("GET").Path("/").HandlerFunc(hello)

    if err := http.ListenAndServe(":8080", r); err != nil {
        log.Fatal(err)
    }
}

query

package main

import (
    "fmt"
    "log"
    "net/http"

    "github.com/gorilla/mux"
)

func hello(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "hello\n")
    q := r.URL.Query()
    if name, ok := q["name"]; ok {
        fmt.Fprintf(w, name[0])
    }
}

func main() {
    r := mux.NewRouter()
    r.Methods("GET").Path("/").HandlerFunc(hello)

    if err := http.ListenAndServe(":8080", r); err != nil {
        log.Fatal(err)
    }
}

gorilla/mux path parameter

package main

import (
    "fmt"
    "log"
    "net/http"

    "github.com/gorilla/mux"
)

func greeting(w http.ResponseWriter, r *http.Request) {
    vars := mux.Vars(r)
    fmt.Fprintf(w, vars["greeting"])
}

func main() {
    r := mux.NewRouter()
    r.HandleFunc("/{greeting}", greeting)

    if err := http.ListenAndServe(":8080", r); err != nil {
        log.Fatal(err)
    }
}

POST form

package main

import (
    "fmt"
    "log"
    "net/http"

    "github.com/gorilla/mux"
)

func postHello(w http.ResponseWriter, r *http.Request) {
    name := r.FormValue("name")
    fmt.Fprintf(w, "hello, %v", name)
}

func main() {
    r := mux.NewRouter()
    r.Methods("POST").Path("/").HandlerFunc(postHello)

    if err := http.ListenAndServe(":8080", r); err != nil {
        log.Fatal(err)
    }
}

POST json

package main

import (
    "encoding/json"
    "fmt"
    "log"
    "net/http"

    "github.com/gorilla/mux"
)

type Hello struct {
    Name string `json="name"`
}

func parseJsonRequest(w http.ResponseWriter, r *http.Request, data interface{}) (int, error) {
    //Validate request
    if r.Method != "POST" {
        return http.StatusBadRequest, fmt.Errorf("Bad method")
    }

    if r.Header.Get("Content-Type") != "application/json" {
        return http.StatusBadRequest, fmt.Errorf("Bad content type")
    }

    decoder := json.NewDecoder(r.Body)
    if err := decoder.Decode(&data); err != nil {
        return http.StatusInternalServerError, err      
    }
    return http.StatusOK, nil
}

func postHello(w http.ResponseWriter, r *http.Request) {
    data := Hello{}
    status, err := parseJsonRequest(w, r, &data)
    if err != nil {
        w.WriteHeader(status)
        return
    }
    w.WriteHeader(status)

    encoder := json.NewEncoder(w)
    encoder.Encode(data)
}

func main() {
    r := mux.NewRouter()
    r.Methods("POST").Path("/").HandlerFunc(postHello)

    if err := http.ListenAndServe(":9999", r); err != nil {
        log.Fatal(err)
    }
}

Handler (ServeHTTP)

package main

import (
    "fmt"
    "log"
    "net/http"

    "github.com/gorilla/mux"
)

type Greeting struct {
    message string
}

func (g *Greeting) ServeHTTP (w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, g.message)
}

func main() {
    hello := Greeting{message: "hello"}
    r := mux.NewRouter()
    r.Methods("GET").Path("/").Handler(&hello)

    if err := http.ListenAndServe(":8080", r); err != nil {
        log.Fatal(err)
    }
}