JSON
JSON is quickly becoming the ubiquitous serialization format for web APIs, so
it may be the most relevant when learning how to build web apps
using Go. Fortunately, Go makes it simple to work with JSON — it is
extremely easy to turn existing Go structs into JSON using the encoding/json
package from the standard library.
package main
import (
"encoding/json"
"net/http"
)
type Book struct {
Title string `json:"title"`
Author string `json:"author"`
}
func main() {
http.HandleFunc("/", ShowBooks)
http.ListenAndServe(":8080", nil)
}
func ShowBooks(w http.ResponseWriter, r *http.Request) {
book := Book{"Building Web Apps with Go", "Jeremy Saenz"}
js, err := json.Marshal(book)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
w.Header().Set("Content-Type", "application/json")
w.Write(js)
}
Exercises
- Read through the JSON API docs and find out how to rename and ignore fields for JSON serialization.
- Instead of using the
json.Marshal
method, try using thejson.Encoder
API. - Figure our how to pretty print JSON with the
encoding/json
package.