如何正确将json字符串转换为对象

Question

I have a Beam pipeline written in Go and I'd like to transform this input:

{"name": "Bob", "age": 32}

to a valid "object".

The go sdk has this function in the encoding package :

// UnmarshalJSON sets the state of this instance from the passed in JSON.
func (w *EncodedType) UnmarshalJSON(buf []byte) error {
    var s string
    if err := json.Unmarshal(buf, &s); err != nil {
        return err
    }
    t, err := graphx.DecodeType(s)
    if err != nil {
        return err
    }
    w.T = t
    return nil
}

But I don't understand how to use it as a step of my pipeline.

Answer 1

You're sort of on the right track. Go doesn't have "objects" in the normal sense of the word as it pertains to programming. You would use a struct like this:

    type User struct {
        Name    string `json:"name"`
        Age     int    `json:"age"`
    }

You would use that to unmarshal into that structure like this:

    var myUser User
    err := json.Unmarshal([]byte(`{"name": "Bob", "age": 32}`), &myUser)
    if err != nil {
        fmt.Println(err)
        return
    }
    fmt.Println(myUser.Name, myUser.Age)

Here is a playground example: https://play.golang.org/p/_uHZ9Q_j-p1

More information: https://blog.golang.org/json-and-go