golang-显示字符，不显示ascii。 类似于“＆”，而不是“ \ 0026”

Question

This is my testing code.Just make a simple http server. Then generating a json data that it's value is "&". But the result is what i don't want. The result is below the code block.

package main

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

func testFunc(w http.ResponseWriter, r *http.Request) {
    data := make(map[string]string)
    data["key"] = "&"
    bytes, err := json.Marshal(data)
    if err != nil {
        fmt.Fprintln(w, "generator json error")
    } else {
        //print console
        fmt.Println(string(bytes))
        fmt.Println("&")
        //print broswer
        fmt.Fprintln(w, string(bytes))
        fmt.Fprintln(w, "&")
    }
}

func main() {
    http.HandleFunc("/", testFunc)
    err := http.ListenAndServe(":9090", nil)
    if err != nil {
        log.Fatal("ListenAndServe", err)
    }

}

result: Chrome browser show:

{"key":"\u0026"}

&

Console also show:

{"key":"\u0026"}

&

When '&' not in json, browser and console will print '&'.

Answer 1

From the docs (emphasis by me):

String values encode as JSON strings. InvalidUTF8Error will be returned if an invalid UTF-8 sequence is encountered. The angle brackets "<" and ">" are escaped to "\u003c" and "\u003e" to keep some browsers from misinterpreting JSON output as HTML. Ampersand "&" is also escaped to "\u0026" for the same reason.

Apparently if you want to send '&' as is, you'll need to either create a custom Marshaler, or use RawMessage type like this: http://play.golang.org/p/HKP0eLogQX.