golang json.Marshal 特殊 html 字符被转义解决方案

go 语言提供了 json 的编解码包，json 字符串作为参数值传输时发现，json.Marshal 生成 json 特殊字符 <、>、&会被转义。

type Test struct {
	Content string
}

func main() {
	t := new(Test)
	t.Content = "http://www.baidu.com?id=123&test=1"
	jsonByte, _ := json.Marshal(t)
	fmt.Println(string(jsonByte))
}

{"Content":"http://www.baidu.com?id=123\u0026test=1"}
Process finished with exit code 0

GoDoc 描述

String values encode as JSON strings coerced to valid UTF-8,
replacing invalid bytes with the Unicode replacement rune.
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.
This escaping can be disabled using an Encoder that had SetEscapeHTML(false) alled on it.

json.Marshal 默认 escapeHtml 为 true,会转义 <、>、&

func Marshal(v interface{}) ([]byte, error) {
	e := &encodeState{}
	err := e.marshal(v, encOpts{escapeHTML: true})
	if err != nil {
		return nil, err
	}
	return e.Bytes(), nil
}

解决方案

方法一：

content = strings.Replace(content, "\\u003c", "<", -1)
content = strings.Replace(content, "\\u003e", ">", -1)
content = strings.Replace(content, "\\u0026", "&", -1)

这种方式比较直接，硬性字符串替换。比较憨厚

方法二：

文档中写到This escaping can be disabled using an Encoder that had SetEscapeHTML(false) alled on it.

1. 我们先创建一个 buffer 用于存储 json
2. 创建一个 jsonencoder
3. 设置 html 编码为 false

type Test struct {
	Content string
}

func main() {
	t := new(Test)
	t.Content = "http://www.baidu.com?id=123&test=1"
	bf := bytes.NewBuffer([]byte{})
	jsonEncoder := json.NewEncoder(bf)
	jsonEncoder.SetEscapeHTML(false)
	jsonEncoder.Encode(t)
	fmt.Println(bf.String())
}

{"Content":"http://www.baidu.com?id=123&test=1"}
Process finished with exit code 0

查看文档和源码还是解决问题的好方法