Golang Json.Marshal错误

I have been trying to encode a map into JSON but I have been unsuccessful so far. Json.Marshal is not encoding value, its just encoding the key.

https://gist.github.com/rahulpache/9174490

package main 
import (
    "encoding/json"
    "fmt"
)
type node struct {
    value   string
    expiry  float64
    settime float64
}

func main() {
    var x = make(map[string]node)

    x["hello"] = node{value: "world", expiry: 1, settime: 2}
    x["foo"] = node{value: "bar", expiry: 1, settime: 2}

    a, err := json.Marshal(x)
    fmt.Println(string(a))
}

Output:

{"foo":{},"hello":{}}

Your properties and the type name are private, if you want your properties to be public you need to follow the convention of capitalizing each word e.g. (Value instead of value) to make it public, switch your type to this and it should serialize just fine.

type Node struct {
    Value   string
    Expiry  float64
    Settime float64
}