golang实现restful

go mod init example.com/restful-api
go get GitHub.com/gorilla/mux
go get github.com/jinzhu/gorm
go get github.com/go-sql-driver/Mysql

package main

import (
    "log"
    "net/http"

    "example.com/restful-api/handlers"
    "github.com/gorilla/mux"
)

func main() {
    r := mux.NewRouter()

    r.HandleFunc("/users", handlers.GetUsers).Methods("GET")
    r.HandleFunc("/users", handlers.CreateUser).Methods("POST")
    r.HandleFunc("/users/{id}", handlers.GetUser).Methods("GET")
    r.HandleFunc("/users/{id}", handlers.UpdateUser).Methods("PUT")
    r.HandleFunc("/users/{id}", handlers.DeleteUser).Methods("DELETE")

    log.Fatal(http.ListenAndServe(":8080", r))
}

package models

import "github.com/jinzhu/gorm"

type User struct {
    gorm.Model
    Name  string `gorm:"not null"`
    Email string `gorm:"not null;unique_index"`
    Age   int    `gorm:"not null"`
}

package handlers

import (
    "encoding/JSON"
    "fmt"
    "net/http"
    "strconv"

    "example.com/restful-api/models"
    "github.com/gorilla/mux"
    "github.com/jinzhu/gorm"
)

var db *gorm.DB

func init() {
    var err error
    db, err = gorm.Open("mysql", "{username}:{passWord}@tcp({host}:{port})/{database}")
    if err != nil {
        panic("failed to connect database")
    }
    db.AutoMigrate(&models.User{})
}

func GetUsers(w http.ResponseWriter, r *http.Request) {
    var users []models.User
    db.Find(&users)
    json.NewEncoder(w).Encode(users)
}

func GetUser(w http.ResponseWriter, r *http.Request) {
    params := mux.Vars(r)
    id, _ := strconv.Atoi(params["id"])
    var user models.User
    db.First(&user, id)
    json.NewEncoder(w).Encode(user)
}

func CreateUser(w http.ResponseWriter, r *http.Request) {
    var user models.User
    json.NewDecoder(r.Body).Decode(&user)
    db.Create(&user)
    json.NewEncoder(w).Encode(user)
}

func UpdateUser(w http.ResponseWriter, r *http.Request) {
    params := mux.Vars(r)
    id, _ := strconv.Atoi(params["id"])
    var user models.User
    db.First(&user, id)
    json.NewDecoder(r.Body).Decode(&user)
    db.Save(&user)
    json.NewEncoder(w).Encode(user)
}

func DeleteUser(w http.ResponseWriter, r *http.Request) {
    params := mux.Vars(r)
    id, _ := strconv.Atoi(params["id"])
    var user models.User
    db.Delete(&user, id)
    fmt.Fprintf(w, "User #%d deleted successfully", id)
}