HTTP Servers

JSON Response Text

Many handlers return JSON-shaped text with stable field names.

json response A handler can build a small JSON response body from deterministic values.

JSON Response Text

name
json_response.go
Replay: real traced execution (multi-file project)
package main

import "fmt"

func main() {
	var name = "Ada"
	status := "active"
	body := "{\"name\":\"" + name + "\",\"status\":\"" + status + "\"}"
	headers := map[string]string{
		"Content-Type": "application/json",
	}

	fmt.Println("name=", name)
	fmt.Println("contentType=", headers["Content-Type"])
	fmt.Println("body=", body)
}

package main

import "fmt"

func main() {
	var name = "Linus"
	status := "active"
	body := "{\"name\":\"" + name + "\",\"status\":\"" + status + "\"}"
	headers := map[string]string{
		"Content-Type": "application/json",
	}

	fmt.Println("name=", name)
	fmt.Println("contentType=", headers["Content-Type"])
	fmt.Println("body=", body)
}

package main

import "fmt"

func main() {
	var name = "Grace"
	status := "active"
	body := "{\"name\":\"" + name + "\",\"status\":\"" + status + "\"}"
	headers := map[string]string{
		"Content-Type": "application/json",
	}

	fmt.Println("name=", name)
	fmt.Println("contentType=", headers["Content-Type"])
	fmt.Println("body=", body)
}

  1. name ← "Ada", status ← "active", body ← "{\"name\":\"Ada\",\"status\":\"active\"}"

    5func main() {6  var name→ "Ada" = "Ada" //@name="Linus", "Grace"7  status→ "active" := "active"8  body→ "{\"name\":\"Ada\",\"status\":\"active\"}" := "{\"name\":\"" + name"Ada" + "\",\"status\":\"" + status"active" + "\"}"9  headers→ map[string]string{"Content-Type":"application/json"} := map[string]string{10    "Content-Type": "application/json",11  }1213  fmt.Println("name=", name"Ada")14  fmt.Println("contentType=", headers["Content-Type"]"application/json")15  fmt.Println("body=", body"{\"name\":\"Ada\",\"status\":\"active\"}")16}
    outputname= Ada
contentType= application/json
body= {"name":"Ada","status":"active"}

  1. name ← "Linus", status ← "active", body ← "{\"name\":\"Linus\",\"status\":\"active\"}"

    5func main() {6  var name→ "Linus" = "Linus"7  status→ "active" := "active"8  body→ "{\"name\":\"Linus\",\"status\":\"active\"}" := "{\"name\":\"" + name"Linus" + "\",\"status\":\"" + status"active" + "\"}"9  headers→ map[string]string{"Content-Type":"application/json"} := map[string]string{10    "Content-Type": "application/json",11  }1213  fmt.Println("name=", name"Linus")14  fmt.Println("contentType=", headers["Content-Type"]"application/json")15  fmt.Println("body=", body"{\"name\":\"Linus\",\"status\":\"active\"}")16}
    outputname= Linus
contentType= application/json
body= {"name":"Linus","status":"active"}

  1. name ← "Grace", status ← "active", body ← "{\"name\":\"Grace\",\"status\":\"active\"}"

    5func main() {6  var name→ "Grace" = "Grace"7  status→ "active" := "active"8  body→ "{\"name\":\"Grace\",\"status\":\"active\"}" := "{\"name\":\"" + name"Grace" + "\",\"status\":\"" + status"active" + "\"}"9  headers→ map[string]string{"Content-Type":"application/json"} := map[string]string{10    "Content-Type": "application/json",11  }1213  fmt.Println("name=", name"Grace")14  fmt.Println("contentType=", headers["Content-Type"]"application/json")15  fmt.Println("body=", body"{\"name\":\"Grace\",\"status\":\"active\"}")16}
    outputname= Grace
contentType= application/json
body= {"name":"Grace","status":"active"}