如何防止转义JSON编码器产生的字符串中的某些字符？

Question

I have a map to save json entries. Here is a preview from my code.

mp := map[string]string{"key": "The Knight & Day"}
fmt.Println(mp)
bty3, err := json.Marshal(mp)
fmt.Println(bty3, err)
fmt.Println(string(bty3))

The output is following-

map[key:The Knight & Day]
[123 34 107 101 121 34 58 34 84 104 101 32 75 110 105 103 104 116 32 92 117 48 48 50 54 32 68 97 121 34 125] <nil>
{"key":"The Knight \u0026 Day"}

What can I do in order to preserve special characters?

Answer 1

The encoding/json docs show the characters that are escaped by default are <, >, and &.

You can use strconv.Unquote like in this answer: How to convert escape characters in HTML tags?

Something straightforward like this would work too:

bty3 = bytes.Replace(bty3, []byte(`\u003c`), []byte("<"), -1)
bty3 = bytes.Replace(bty3, []byte(`\u003e`), []byte(">"), -1)
bty3 = bytes.Replace(bty3, []byte(`\u0026`), []byte("&"), -1)

In the upcoming Go1.7 release, you can turn off the escaping in a json.Encoder with SetEscapeHTML(false).

mp := map[string]string{"key": "The Knight & Day"}
var buf bytes.Buffer

enc := json.NewEncoder(&buf)
enc.SetEscapeHTML(false)
enc.Encode(mp)

fmt.Println(&buf)

Which prints

{"key":"The Knight & Day"}