如何使用mongo-go-driver有效地将bson转换为json? [英] How to convert bson to json effectively with mongo-go-driver?
问题描述
我想将 mongo-go-driver 中的bson转换为json。
I want to convert bson in mongo-go-driver to json effectively.
我应该小心处理 NaN
,因为 json.Marshal $ c如果数据中存在
NaN
,则$ c>失败。
I should take care to handle NaN
, because json.Marshal
fail if NaN
exists in data.
例如,我要将下面的bson数据转换为json 。
For instance, I want to convert below bson data to json.
b, _ := bson.Marshal(bson.M{"a": []interface{}{math.NaN(), 0, 1}})
// How to convert b to json?
以下操作失败。
// decode
var decodedBson bson.M
bson.Unmarshal(b, &decodedBson)
_, err := json.Marshal(decodedBson)
if err != nil {
panic(err) // it will be invoked
// panic: json: unsupported value: NaN
}
推荐答案
如果您知道BSON的结构,则可以创建一个实现 json.Marshaler
和 json.Unmarshaler
接口的自定义类型,并根据需要处理NaN。例如:
If you know the structure if your BSON, you can create a custom type that implements the json.Marshaler
and json.Unmarshaler
interfaces, and handles NaN as you wish. Example:
type maybeNaN struct{
isNan bool
number float64
}
func (n maybeNaN) MarshalJSON() ([]byte, error) {
if n.isNan {
return []byte("null"), nil // Or whatever you want here
}
return json.Marshal(n.number)
}
func (n *maybeNan) UnmarshalJSON(p []byte) error {
if string(p) == "NaN" {
n.isNan = true
return nil
}
return json.Unmarshal(p, &n.number)
}
type myStruct struct {
someNumber maybeNaN `json:"someNumber" bson:"someNumber"`
/* ... */
}
如果您的BSON具有任意结构,则唯一的选择是使用反射,并将所有出现的NaN转换为类型(可能是如上所述的自定义类型)
If you have an arbitrary structure of your BSON, your only option is to traverse the structure, using reflection, and convert any occurrences of NaN into a type (possibly a custom type as described above)
这篇关于如何使用mongo-go-driver有效地将bson转换为json?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!