目錄
- 公共代碼區(qū)域
- 一、map, struct 互轉(zhuǎn)
- 1.map 轉(zhuǎn) struct
- 2、struct 轉(zhuǎn) map
- 二、struct, json 互轉(zhuǎn)
- 三、map, json 互轉(zhuǎn)
- 1.map 轉(zhuǎn) json
- 2.json 轉(zhuǎn) map
- 總結(jié)
本文用于記錄我在 golang 學(xué)習(xí)階段遇到的類型轉(zhuǎn)換問(wèn)題，針對(duì)的是 json 、map、struct 之間相互轉(zhuǎn)換的問(wèn)題，用到的技術(shù) json 、mapstructure、reflect 三個(gè)類庫(kù)
公共代碼區(qū)域
package main
import (
"encoding/json"
"fmt"
"testing"
)
type UserInfoVo struct {
Id string `json:"id"`
UserName string `json:"user_name"`
Address []AddressVo `json:"address"`
}
type AddressVo struct {
Address string `json:"address"`
}
var beforeMap = map[string]interface{}{
"id": "123",
"user_name": "酒窩豬",
"address": []map[string]interface{}{{"address": "address01"}, {"address": "address02"}},
}
var User UserInfoVo
func init() {
User = UserInfoVo{
Id: "01",
UserName: "酒窩豬",
Address: []AddressVo{
{
Address: "湖南",
},
{
Address: "北京",
},
},
}
}
一、map, struct 互轉(zhuǎn)
1.map 轉(zhuǎn) struct
map 轉(zhuǎn) struct 有兩種方式
1.是通過(guò)第三方包 github.com/mitchellh/mapstructure
2.通過(guò) map 轉(zhuǎn) json，再通過(guò) json 轉(zhuǎn) struct
第三方包 mapstructure
下載依賴，通過(guò)第三方依賴進(jìn)行轉(zhuǎn)換
go get github.com/goinggo/mapstructure
func TestMapToStructByMod(t *testing.T) {
var afterStruct =UserInfoVo{}
before := time.Now()
err := mapstructure.Decode(beforeMap, afterStruct)
if err!=nil{
fmt.Println(err)
}
fmt.Printf("result:%+v \n",time.Since(before))
fmt.Printf("result:%+v \n",afterStruct)
}
result:61.757µs
result:{Id:123 UserName: Address:[{Address:address01} {Address:address02}]}
--- PASS: TestMapToStructByMod (0.00s)
PASS
通過(guò) JSON 進(jìn)行轉(zhuǎn)換
先將 map 轉(zhuǎn)換成 JSON，再通過(guò) JSON 轉(zhuǎn)換成 struct
操作有點(diǎn)繁瑣
func TestMapToStructByJson(t *testing.T) {
beforeMap := map[string]interface {}{
"id":"123",
"user_name":"酒窩豬",
"address":[]map[string]interface{}{{"address": "address01"}, {"address": "address02"}},
}
var afterStruct =UserInfoVo{}
before := time.Now()
marshal, err := json.Marshal(beforeMap)
if err!=nil{
fmt.Println("marshal:",err)
return
}
err = json.Unmarshal(marshal, afterStruct)
if err!=nil{
fmt.Println("unmarshal:",err)
return
}
fmt.Println(time.Since(before))
fmt.Printf("resutlt: %+v",afterStruct)
}
134.299µs
resutlt: {Id:123 UserName:酒窩豬 Address:[{Address:address01} {Address:address02}]}--- PASS: TestMapToStructByJson (0.00s)
PASS
總結(jié)
問(wèn)題：
論性能哪個(gè)更佳？
根據(jù)結(jié)果答案
使用 JSON 需要時(shí)間是 134.299µs
使用 mapstructure 需要時(shí)間是 61.757µs
結(jié)果是使用第三方包 mapstructure 性能更好，那么，是因?yàn)槭裁茨?？暫且按下不?/p>
2、struct 轉(zhuǎn) map
JSON 序列化轉(zhuǎn)換
先將 struct 轉(zhuǎn)換成字節(jié)數(shù)組，再將字節(jié)數(shù)組轉(zhuǎn)換成 map 打印
func TestStructToMapByJson(t *testing.T) {
var resultMap interface{}
before := time.Now()
jsonMarshal, _ := json.Marshal(User)
err := json.Unmarshal(jsonMarshal, resultMap)
if err != nil {
fmt.Println(err)
return
}
fmt.Println(time.Since(before))
fmt.Printf("%+v",resultMap)
}
158.857µs
map[address:[map[address:湖南] map[address:北京]] id:01 user_name:酒窩豬]--- PASS: TestStructToMapByJson (0.00s)
PASS
通過(guò)反射轉(zhuǎn)換
通過(guò)反射獲取 User 的類型與值
func TestStructToMapByReflect(t *testing.T) {
var resultMap = make(map[string]interface{},10)
before := time.Now()
ty:=reflect.TypeOf(User)
v:=reflect.ValueOf(User)
for i := 0; i v.NumField(); i++ {
resultMap[strings.ToLower(ty.Field(i).Name)]=v.Field(i).Interface()
}
fmt.Println(time.Since(before))
fmt.Printf("%+v",resultMap)
}
13.965µs
map[address:[{Address:湖南} {Address:北京}] id:01 username:酒窩豬]--- PASS: TestStructToMapByReflect (0.00s)
PASS
總結(jié)
問(wèn)題：論性能哪個(gè)更佳？
答案是使用反射的效果更快點(diǎn)，沒(méi)有那么多繁瑣的轉(zhuǎn)換，記住在 make 中進(jìn)行初始化大小，我試了下，不指定大小與指定大小時(shí)間上有 3~4µs 的區(qū)別
網(wǎng)絡(luò)上還有一種方法是使用 structs 包，不過(guò)我看了下，該依賴包已經(jīng)三年沒(méi)更新了
二、struct, json 互轉(zhuǎn)
1. struct 轉(zhuǎn) json
func TestStructToJsonByJson(t *testing.T) {
before := time.Now()
marshal, _ := json.Marshal(User)
fmt.Println(time.Since(before))
fmt.Printf("%s", marshal)
}
116.068µs
{"id":"01","user_name":"酒窩豬","address":[{"address":"湖南"},{"address":"北京"}]}--- PASS: TestStructToJsonByJson (0.00s)
PASS
2.json 轉(zhuǎn) struct
func TestJsonToStructByJson(t *testing.T) {
info:=UserInfoVo{}
marshal, _ := json.Marshal(User)
before := time.Now()
json.Unmarshal(marshal,info)
fmt.Println(time.Since(before))
fmt.Printf("%+v",info)
}
23.009µs
{Id:01 UserName:酒窩豬 Address:[{Address:湖南} {Address:北京}]}--- PASS: TestJsonToStructByJson (0.00s)
PASS
三、map, json 互轉(zhuǎn)
1.map 轉(zhuǎn) json
func TestMapToJson(t *testing.T) {
before := time.Now()
marshal, _ := json.Marshal(beforeMap)
fmt.Println(time.Since(before))
fmt.Printf("%s", marshal)
}
75.133µs
{"address":[{"address":"address01"},{"address":"address02"}],"id":"123","user_name":"酒窩豬"}--- PASS: TestMapToJson (0.00s)
PASS
2.json 轉(zhuǎn) map
func TestJsonToMap(t *testing.T) {
marshal, _ := json.Marshal(beforeMap)
resultMap:=make(map[string]interface{},10)
before := time.Now()
json.Unmarshal(marshal,resultMap)
fmt.Println(time.Since(before))
fmt.Printf("%+v", resultMap)
}
28.728µs
map[address:[map[address:address01] map[address:address02]] id:123 user_name:酒窩豬]--- PASS: TestJsonToMap (0.00s)
PASS
總結(jié)
三者之間的轉(zhuǎn)換更多的是關(guān)于如果使用 json 內(nèi)庫(kù)，只有在 map 轉(zhuǎn) struct 使用了 mapstructure，struct 轉(zhuǎn) map 使用了反射，其他轉(zhuǎn)換，更多的是使用 json 內(nèi)置庫(kù)進(jìn)行轉(zhuǎn)換
到此這篇關(guān)于golang struct, map, json之間的相互轉(zhuǎn)換的文章就介紹到這了,更多相關(guān)golang struct, map, json 內(nèi)容請(qǐng)搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！
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