main.go

package main

import (
	"encoding/json"
	"fmt"

	simpleJson "github.com/bitly/go-simplejson"
)

type User struct {
	Name     string
	Age      uint16
	Articles []Article
}

func (u *User) UnmarshalJSON(data []byte) error {
	js, err := simpleJson.NewJson(data)
	if err != nil {
		return err
	}

	u.Name, err = js.Get("Name").String()
	if err != nil {
		return err
	}

	var age uint64
	age, err = js.Get("Age").Uint64()
	if err != nil {
		return err
	}
	u.Age = uint16(age)

	// Article
	var bytes []byte
	bytes, err = js.Get("Articles").Encode()
	if err != nil {
		return err
	}

	var as []Article
	if err := json.Unmarshal(bytes, &as); err != nil {
		return err
	}
	u.Articles = as

	return nil
}

type Article struct {
	Title   string
	Content string
}

func (a *Article) UnmarshalJSON(data []byte) error {
	js, err := simpleJson.NewJson(data)
	if err != nil {
		return err
	}

	a.Title, err = js.Get("Title").String()
	if err != nil {
		return err
	}

	a.Content, err = js.Get("Content").String()
	if err != nil {
		return err
	}
	return nil
}

func main() {
	var jsonStr = `{
		"Name": "Ken",
		"Age": 32,
		"Articles": [
			{"Title": "Title A", "Content": "content"},
			{"Title": "Title B", "Content": "content"}
		]
	}`
	var u User

	err := json.Unmarshal([]byte(jsonStr), &u)
	if err != nil {
		panic(err)
	}

	fmt.Println(u) // {Ken 32 [{Title A content} {Title B content}]}
}