JSON 데이터 주고받기

용어 :

1. MUX (= ROUTER) : 경로에 따라 다르게 분배해주는 것

// "/bar"를 통하여 라우팅 된다.
ex) http.HandleFunc("/bar", barHandler)

Mux 사용해보기

mux를 사용하여 동적 등록

package main

import (
	"fmt"
	"net/http"
)

type fooHandler struct{}

func (f *fooHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	fmt.Fprint(w, "Hello Foo!")
}

func barHandler(w http.ResponseWriter, r *http.Request) {
	fmt.Fprint(w, "Hello Bar!!")
}

func main() {

	mux := http.NewServeMux()

	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprint(w, "Hello World")
	})

	mux.HandleFunc("/bar", barHandler)

	mux.Handle("/foo", &fooHandler{})

	http.ListenAndServe(":8080", mux)
}

Request에서 필요한 Input 값 가져오기

package main

import (
	"fmt"
	"net/http"
)

type fooHandler struct{}

func (f *fooHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	fmt.Fprint(w, "Hello Foo!")
}

func barHandler(w http.ResponseWriter, r *http.Request) {
	name := r.URL.Query().Get("name")
	if name == "" {
		name = "World"
	}
	fmt.Fprintf(w, "Hello  %s!", name)
}

func main() {

	mux := http.NewServeMux()

	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprint(w, "Hello World")
	})

	mux.HandleFunc("/bar", barHandler)

	mux.Handle("/foo", &fooHandler{})

	http.ListenAndServe(":8080", mux)
}

JSON 사용하기

package main

import (
	"encoding/json"
	"fmt"
	"net/http"
	"time"
)

type User struct {
	FirstName string    `json:"first_name"`
	LastName  string    `json:"last_name"`
	Email     string    `json:"email"`
	CreateAt  time.Time `json:"timestamp"`
}

type fooHandler struct{}

func (f *fooHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	//user구조체를 담을 user 선언
	user := new(User)
	// json형 데이터는 Request의 Body에 저장
	err := json.NewDecoder(r.Body).Decode(user)
	if err != nil {
		w.WriteHeader(http.StatusBadRequest)
		fmt.Fprint(w, "Bad Request : ", err)
		return
	}
	user.CreateAt = time.Now()

	data, _ := json.Marshal(user)
	w.WriteHeader(http.StatusOK)
	fmt.Fprint(w, string(data))

}

func barHandler(w http.ResponseWriter, r *http.Request) {
	name := r.URL.Query().Get("name")
	if name == "" {
		name = "World"
	}
	fmt.Fprintf(w, "Hello  %s!", name)
}

func main() {

	mux := http.NewServeMux()

	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprint(w, "Hello World")
	})

	mux.HandleFunc("/bar", barHandler)

	mux.Handle("/foo", &fooHandler{})

	http.ListenAndServe(":5000", mux)
}

1. JSON 테스트를 위하여 설치