Go言語でstructをmapに変換する ref: http://qiita.com/keitaj/items/440a50a53c8980ee338f

file0.go

package main

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

func StructToMap(data interface{}) map[string]interface{} {
  result := make(map[string]interface{})
  elem := reflect.ValueOf(data).Elem()
  size := elem.NumField()

  for i := 0; i < size; i++ {
    field := elem.Type().Field(i).Name
    value := elem.Field(i).Interface()
    result[field] = value
  }

  return result
}

func StructToJsonTagMap(data interface{}) map[string]interface{} {
  result := make(map[string]interface{})
  elem := reflect.ValueOf(data).Elem()
  size := elem.NumField()

  for i := 0; i < size; i++ {
    field := elem.Type().Field(i).Tag.Get("json")
    value := elem.Field(i).Interface()
    result[field] = value
  }

  return result
}

func StructToJsonTagMap2(data interface{}) map[string]interface{} {
  result := make(map[string]interface{})

  b, _ := json.Marshal(data)
  json.Unmarshal(b, &result)

  return result
}

type A struct {
    ID int `json:"id"`
    Name string `json:"name"`
}

func main() {
    a := A{1, "keitaj"}
    fmt.Println(a)

    b := StructToMap(&a)
    fmt.Println(b)

    c := StructToJsonTagMap(&a)
    fmt.Println(c)

    d := StructToJsonTagMap2(&a)
    fmt.Println(d)
}

file0.txt

package main

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

func StructToMap(data interface{}) map[string]interface{} {
  result := make(map[string]interface{})
  elem := reflect.ValueOf(data).Elem()
  size := elem.NumField()

  for i := 0; i < size; i++ {
    field := elem.Type().Field(i).Name
    value := elem.Field(i).Interface()
    result[field] = value
  }

  return result
}

func StructToJsonTagMap(data interface{}) map[string]interface{} {
  result := make(map[string]interface{})
  elem := reflect.ValueOf(data).Elem()
  size := elem.NumField()

  for i := 0; i < size; i++ {
    field := elem.Type().Field(i).Tag.Get("json")
    value := elem.Field(i).Interface()
    result[field] = value
  }

  return result
}

func StructToJsonTagMap2(data interface{}) map[string]interface{} {
  result := make(map[string]interface{})

  b, _ := json.Marshal(data)
  json.Unmarshal(b, &result)

  return result
}

type A struct {
    ID int `json:"id"`
    Name string `json:"name"`
}

func main() {
    a := A{1, "keitaj"}
    fmt.Println(a)

    b := StructToMap(&a)
    fmt.Println(b)

    c := StructToJsonTagMap(&a)
    fmt.Println(c)

    d := StructToJsonTagMap2(&a)
    fmt.Println(d)
}

file1.go

{1 keitaj}
map[ID:1 Name:keitaj]
map[id:1 name:keitaj]
map[name:keitaj id:1]

file1.txt

{1 keitaj}
map[ID:1 Name:keitaj]
map[id:1 name:keitaj]
map[name:keitaj id:1]