Golang : HTTP response JSON encoded data

Alright, time to get dirty again.

I need to do a quick and easy http.Get() from another server(let say server A) to retrieve some JSON encoded data. On server A, to fulfill request from the client, I need to write a simple Go program that serve JSON encoded data. Not entirely a RESTful API server, but nearly there.

Golang made it pretty easy to achieve this. The codes below demonstrate how to reply in JSON and to make this tutorial easy to understand. I've omitted couple of things like :

• connecting to database such as MySQL or MariaDB

• routing based on URL's path and URI segment data

it is just to simulate a reply in JSON format based on given data in the URL's path.

 package main

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

 type JsonResponse map[string]interface{}

 func (jr JsonResponse) String() (str string) { // add this method to print out String
 byte, err := json.Marshal(jr)
 if err != nil {
 str = "" // return empty
 return
 }
 str = string(byte) //ok,return cast byte to string
 return
 }

 func JsonReplyAdam(w http.ResponseWriter, r *http.Request) {
 w.Header().Set("Content-Type", "application/json")
 fmt.Fprint(w, JsonResponse{"name": "Adam", "age": 36, "job": "CEO", "success": true})
 }


 func JsonReplyEve(w http.ResponseWriter, r *http.Request) {
 w.Header().Set("Content-Type", "application/json")
 fmt.Fprint(w, JsonResponse{"name": "Eve", "age": 30, "job": "CFO", "success": true})
 }

 func main() {
 // http.Handler

 mux := http.NewServeMux()
 mux.HandleFunc("/adam", JsonReplyAdam)
 mux.HandleFunc("/eve", JsonReplyEve)

 http.ListenAndServe(":8080", mux)
 }

Results :

URL : http://127.0.0.01:8080/eve

{"age":30,"job":"CFO","name":"Eve","success":true}

URL : http://127.0.0.01:8080/adam

{"age":36,"job":"CEO","name":"Adam","success":true}

References :

https://www.socketloop.com/tutorials/golang-get-uri-segments-by-number-and-assign-as-variable-example

https://www.socketloop.com/tutorials/golang-process-json-data-with-jason-package