Json元帅的结构图导致空对象

Question

I have a simple object defined:

type Link struct {
    Href  string `json:"href"`
    Title string `json:"href,omitempty"`
}

type Foo struct {
    Links    map[string]Link     `json:"_links"`
}

foo := new(Foo)
foo.Links = make(map[string]Link, 0)
foo.Links["self"] = Link{Href: "/href"}

After marshalling it to JSON, I'd expect:

{
    "_links": {
        "self": {
            "href": "/href"
        }
    }
}

But instead I get:

{
    "_links": {
        "self": {}
    }
}

Any idea why? Here's a full example:

https://play.golang.org/p/3RA3Mrx3pt

Answer 1

You've defined json:"href" twice:

type Link struct {
    Href  string `json:"href"`
    Title string `json:"href,omitempty"`
}

After changing the second to json:"title" it works: https://play.golang.org/p/uEbyqtHYF8.