Golang:JSON:如何将字符串数组解组为[] int64 [英] Golang: JSON: How do I unmarshal array of strings into []int64
问题描述
Golang encoding/json
包使您可以使用,string
struct标记来将字符串值(如"309230"
)编组/解编为int64
字段.示例:
Golang encoding/json
package lets you use ,string
struct tag in order to marshal/unmarshal string values (like "309230"
) into int64
field. Example:
Int64String int64 `json:",string"`
但是,这不适用于切片,即. []int64
:
However, this doesn't work for slices, ie. []int64
:
Int64Slice []int64 `json:",string"` // Doesn't work.
是否可以将JSON字符串数组编组/解编为[] int64字段?
https://golang.org/pkg/encoding/json 的引用:
字符串"选项表示字段在JSON编码的字符串中存储为JSON.它仅适用于字符串,浮点数,整数或布尔类型的字段.在与JavaScript程序通信时,有时会使用这种额外的编码级别:
The "string" option signals that a field is stored as JSON inside a JSON-encoded string. It applies only to fields of string, floating point, integer, or boolean types. This extra level of encoding is sometimes used when communicating with JavaScript programs:
推荐答案
对于感兴趣的人,我发现了使用自定义类型定义了MarshalJSON()
和UnmarshalJSON()
方法的解决方案.
For anyone interested, I found a solution using a custom type having MarshalJSON()
and UnmarshalJSON()
methods defined.
type Int64StringSlice []int64
func (slice Int64StringSlice) MarshalJSON() ([]byte, error) {
values := make([]string, len(slice))
for i, value := range []int64(slice) {
values[i] = fmt.Sprintf(`"%v"`, value)
}
return []byte(fmt.Sprintf("[%v]", strings.Join(values, ","))), nil
}
func (slice *Int64StringSlice) UnmarshalJSON(b []byte) error {
// Try array of strings first.
var values []string
err := json.Unmarshal(b, &values)
if err != nil {
// Fall back to array of integers:
var values []int64
if err := json.Unmarshal(b, &values); err != nil {
return err
}
*slice = values
return nil
}
*slice = make([]int64, len(values))
for i, value := range values {
value, err := strconv.ParseInt(value, 10, 64)
if err != nil {
return err
}
(*slice)[i] = value
}
return nil
}
上述解决方案将[]int64
编组为JSON字符串数组.取消编组可以从JSON字符串和整数数组进行,即:
The above solution marshals []int64
into JSON string array. Unmarshaling works from both JSON string and integer arrays, ie.:
{"bars": ["1729382256910270462", "309286902808622", "23"]}
{"bars": [1729382256910270462, 309286902808622, 23]}
请参见
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