使用Go解析.Net JSON日期

Question

How can I parse this .Net JSON date with Go? The value comes back unassigned. It appears to parse up to the date field.

package main

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

type MyStruct struct {
    FirstField string
    SomeTime time.Time
    LastField string
}

type MyStructSlice struct {
    MyStructs []MyStruct
}

func main() {
    var s MyStructSlice 
    str := `{"MyStructs":[{"FirstField":"123", "SomeTime":"\/Date(1432187580000-0500)\/", "LastField":"456"}]}`
    json.Unmarshal([]byte(str), &s)
    fmt.Println(s)
}

Go Playground

Answer 1

First you model is wrong, it doesn't model the data structure in your JSON. It should be:

type Data struct {
    Data []MyStruct `json:"data`
}
type MyStruct struct {
    SomeTime string
}

It works with this, try it on the Go Playground.

Problem is that we still have the time as string.

Now if you want SomeTime to be time.Time, you need to parse it yourself, you can do it by implementing json.Unmarshaler:

type Data struct {
    Data []MyStruct `json:"data`
}

type MyStruct struct {
    SomeTime time.Time
}

func (m *MyStruct) UnmarshalJSON(data []byte) error {
    // First unmashal it into a string:
    ms := struct{ SomeTime string }{}
    if err := json.Unmarshal(data, &ms); err != nil {
        return err
    }

    s := ms.SomeTime

    // s is of format: "/Date(1432187580000-0500)/"
    // extract millis and time zone offset hours
    i1 := strings.Index(s, "(")
    i3 := strings.Index(s, ")")
    i2 := strings.Index(s, "-")
    if i2 < 0 {
        i2 = strings.Index(s, "+")
    }
    if i1 < 0 || i2 < 0 || i3 < 0 {
        return errors.New("Invalid format")
    }

    millis, err := strconv.ParseInt(s[i1+1:i2], 10, 64)
    if err != nil {
        return err
    }
    m.SomeTime = time.Unix(0, millis*1000000)

    // Apply timezone:
    zoneHours, err := strconv.ParseInt(s[i2:i3], 10, 64)
    if err != nil {
        return err
    }
    zone := time.FixedZone("something", int(zoneHours)*3600)
    m.SomeTime = m.SomeTime.In(zone)
    return nil
}

Try it on the Go Playground.