Simple JSON API Server in Go

simple-json-api.go

package main

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

// The `json:"whatever"` bit is a way to tell the JSON
// encoder and decoder to use those names instead of the
// capitalised names
type person struct {
        Name string `json:"name"`
        Age  int    `json:"age"`
}

var tom *person = &person{
        Name: "Tom",
        Age:  28,
}

func tomHandler(w http.ResponseWriter, r *http.Request) {

        switch r.Method {
        case "GET":
                // Just send out the JSON version of 'tom'
                j, _ := json.Marshal(tom)
                w.Write(j)
        case "POST":
                // Decode the JSON in the body and overwrite 'tom' with it
                d := json.NewDecoder(r.Body)
                p := &person{}
                err := d.Decode(p)
                if err != nil {
                        http.Error(w, err.Error(), http.StatusInternalServerError)
                }
                tom = p
        default:
                w.WriteHeader(http.StatusMethodNotAllowed)
                fmt.Fprintf(w, "I can't do that.")
        }
}

func main() {
        http.HandleFunc("/tom", tomHandler)

        log.Println("Go!")
        http.ListenAndServe(":8080", nil)
}