Golang struct 中datetime类型字段json格式化

time.Time

package main

import (
    "encoding/json"
    "os"
    "time"
)

type MyStruct struct {
    ID        uint      `json:"id"`
    Name      string    `json:"name"`
    CreatedAt time.Time `json:"created_at"`
}

func main() {
    _ = json.NewEncoder(os.Stdout).Encode(
        &MyStruct{1, "Xander", time.Now()},
    )
}

输出：

{"id":1,"name":"Xander","created_at":"2021-04-13T20:38:51.466566+08:00"}

2006-01-02 15:04:05

MyStructMarshalJSON

func (m *MyStruct) MarshalJSON() ([]byte, error) {
    type Alias MyStruct
    return json.Marshal(&struct {
        *Alias
        CreatedAt string `json:"created_at"`
    }{
        Alias:     (*Alias)(m),
        CreatedAt: m.CreatedAt.Format("2006-01-02 15:04:05"),
    })
}

输出：

 {"id":1,"name":"Xander","created_at":"2021-04-13 20:45:26"}

MarshalJSON

但后续代码中用起来稍微麻烦点

type JSONTime time.Time
// 或者
type JSONTime struct {
    time.Time
}

如：

type JSONTime time.Time

func (t JSONTime)MarshalJSON() ([]byte, error) {
    //do your serializing here
    stamp := fmt.Sprintf("\"%s\"", time.Time(t).Format("2006-01-02 15:04:05"))
    return []byte(stamp), nil
}