Handling JSON Post Request in Go

TomJ picture TomJ · Mar 28, 2013 · Viewed 270.1k times · Source

So I have the following, which seems incredibly hacky, and I've been thinking to myself that Go has better designed libraries than this, but I can't find an example of Go handling a POST request of JSON data. They are all form POSTs.

Here is an example request: curl -X POST -d "{\"test\": \"that\"}" http://localhost:8082/test

And here is the code, with the logs embedded:

package main

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

type test_struct struct {
    Test string
}

func test(rw http.ResponseWriter, req *http.Request) {
    req.ParseForm()
    log.Println(req.Form)
    //LOG: map[{"test": "that"}:[]]
    var t test_struct
    for key, _ := range req.Form {
        log.Println(key)
        //LOG: {"test": "that"}
        err := json.Unmarshal([]byte(key), &t)
        if err != nil {
            log.Println(err.Error())
        }
    }
    log.Println(t.Test)
    //LOG: that
}

func main() {
    http.HandleFunc("/test", test)
    log.Fatal(http.ListenAndServe(":8082", nil))
}

There's got to be a better way, right? I'm just stumped in finding what the best practice could be.

(Go is also known as Golang to the search engines, and mentioned here so others can find it.)

Answer

Joe picture Joe · Mar 28, 2013

Please use json.Decoder instead of json.Unmarshal.

func test(rw http.ResponseWriter, req *http.Request) {
    decoder := json.NewDecoder(req.Body)
    var t test_struct
    err := decoder.Decode(&t)
    if err != nil {
        panic(err)
    }
    log.Println(t.Test)
}