Go implementation of a JSON consuming RESTful API.

#http

#rest

#api

#json

The following is a very barebones PoC implementation of a somewhat RESTful (more CRUD) API that consumes JSON. It's a WIP. Amongst other things the error checking could be better.

The GenUUID function is based upon nu7hatch implementation: https://github.com/nu7hatch/gouuid

package main

import (
 "crypto/rand"
 "encoding/json"
 "fmt"
 "github.com/gorilla/mux"
 "net/http"
)

type Employee struct {
 UUID string `json:"uuid"`
 Name string `json:"name"`
 Position string `json:"position"`
}

var employees map[string]*Employee

func HandleEmployee(rw http.ResponseWriter, req *http.Request) {
 vars := mux.Vars(req)

 switch req.Method {
 case "GET": //READ employee
 fmt.Println("GET /employees/" + vars["uuid"])

 employee := employees[vars["uuid"]]

 js, err := json.Marshal(employee)
 if err != nil {
 http.Error(rw, err.Error(), http.StatusInternalServerError)
 return
 }

 fmt.Fprint(rw, string(js))
 return

 case "PUT": // UPDATE employee
 fmt.Println("PUT /employees/" + vars["uuid"])

 employee := employees[vars["uuid"]]

 dec := json.NewDecoder(req.Body)
 err := dec.Decode(&employee)
 if err != nil {
 http.Error(rw, err.Error(), http.StatusInternalServerError)
 return
 }

 employee.UUID = vars["uuid"]

 retjs, err := json.Marshal(employee)
 if err != nil {
 http.Error(rw, err.Error(), http.StatusInternalServerError)
 return
 }

 fmt.Fprint(rw, string(retjs))

 case "DELETE":
 fmt.Println("DELETE /employees/" + vars["uuid"])

 delete(employees, vars["uuid"])
 fmt.Fprint(rw, "Success")

 }
}

func HandleEmployees(rw http.ResponseWriter, req *http.Request) {
 switch req.Method {
 case "GET": // INDEX employees

 js, err := json.Marshal(employees)
 if err != nil {
 http.Error(rw, err.Error(), http.StatusInternalServerError)
 return
 }

 fmt.Fprint(rw, string(js))

 case "POST": // CREATE employee
 employee := new(Employee)
 employee.UUID = GenUUID()

 dec := json.NewDecoder(req.Body)
 err := dec.Decode(&employee)
 if err != nil {
 http.Error(rw, err.Error(), http.StatusInternalServerError)
 return
 }

 employees[employee.UUID] = employee

 retjs, err := json.Marshal(employee)
 if err != nil {
 http.Error(rw, err.Error(), http.StatusInternalServerError)
 return
 }

 fmt.Fprint(rw, string(retjs))
 }
}

func GenUUID() string {
 uuid := make([]byte, 16)
 _, err := rand.Read(uuid[:])
 if err != nil {
 fmt.Println(err)
 }
 uuid[8] = (uuid[8] | 0x40) & 0x7F
 uuid[6] = (uuid[6] & 0xF) | (4 << 4)
 return fmt.Sprintf("%x-%x-%x-%x-%x", uuid[0:4], uuid[4:6], uuid[6:8], uuid[8:10], uuid[10:])
}

func main() {
 employees = map[string]*Employee{
 "abcde": &Employee{UUID: "abcde", Name: "Matthew Brown", Position: "Gopher"},
 "xyz": &Employee{UUID: "xyz", Name: "Alexander Brown", Position: "Gopher's Assistant"},
 }

 router := mux.NewRouter()
 router.HandleFunc("/employees/{uuid}", HandleEmployee)
 router.HandleFunc("/employees", HandleEmployees)
 http.ListenAndServe(":8080", router)
}