JSON

This example will show how to encode and decode JSON data using the encoding/json package.

  1. // json.go
  2. package main
  4. import (
  5.     "encoding/json"
  6.     "fmt"
  7.     "net/http"
  8. )
  10. type User struct {
  11.     Firstname string `json:"firstname"`
  12.     Lastname  string `json:"lastname"`
  13.     Age       int    `json:"age"`
  14. }
  16. func main() {
  17.     http.HandleFunc("/decode", func(w http.ResponseWriter, r *http.Request) {
  18.         var user User
  19.         json.NewDecoder(r.Body).Decode(&user)
  21.         fmt.Fprintf(w, "%s %s is %d years old!", user.Firstname, user.Lastname, user.Age)
  22.     })
  24.     http.HandleFunc("/encode", func(w http.ResponseWriter, r *http.Request) {
  25.         peter := User{
  26.             Firstname: "John",
  27.             Lastname:  "Doe",
  28.             Age:       25,
  29.         }
  31.         json.NewEncoder(w).Encode(peter)
  32.     })
  34.     http.ListenAndServe(":8080", nil)
  35. }
  1. $ go run json.go
  3. $ curl -s -XPOST -d'{"firstname":"Donald","lastname":"Trump","age":70}' http://localhost:8080/decode
  4. Donald Trump is 70 years old!
  6. $ curl -s http://localhost:8080/encode
  7. {"firstname":"John","lastname":"Doe","age":25}