Golang使用响应中的主体更改HTTP响应状态代码201

How do I set the response status code to 201 while including a JSON object in the response body? I can't seem to perform both of these at once -- either I return a 200 with a message body, or a 201 without one.

I just tried and it seems to work.

Would you have a sample of broken code?

Simple example: (https://play.golang.org/p/xg8lGNofze)

package main

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

func testHdlr(w http.ResponseWriter, req *http.Request) {
    m := map[string]string{
        "foo": "bar",
    }
    w.Header().Add("Content-Type", "application/json")
    w.WriteHeader(http.StatusCreated)
    _ = json.NewEncoder(w).Encode(m)
}

func main() {
    http.HandleFunc("/", testHdlr)
    log.Fatal(http.ListenAndServe(":8080", nil))
}

Then

$> curl -v http://localhost:8080
[...]
< HTTP/1.1 201 Created
< Date: Thu, 25 May 2017 00:54:15 GMT
< Content-Length: 14
< Content-Type: application/json
< 
{ [14 bytes data]
* Curl_http_done: called premature == 0

100    14  100    14    0     0   2831      0 --:--:-- --:--:-- --:--:--  3500
* Connection #0 to host localhost left intact
{"foo":"bar"}