Golang 資料類型轉換（json、struct、map）

Golang 資料類型轉換

一、struct轉json

方法一

package main

import (
	"encoding/json"
	"fmt"
)

type Server struct {
	ServerName string `json:"serverName,string"`
	ServerIP   string `json:"serverIP,omitempty"`
}
type Serverslice struct {
	Did     string
	Servers Server `json:"servers"`
}


func main() {
	//定義struct變量并複制
	var s Serverslice
	s.Servers = Server{ServerName: "Beijing_Base", ServerIP: "127.0.02"}
	//使用(.屬性名）方法指派
	s.Did = "111"
	b, err := json.Marshal(s)
	if err != nil {
		fmt.Println("JSON ERR:", err)
	}
	fmt.Println(s.Did)
	fmt.Println(string(b))
}	
           

輸出結果：

111
{"Did":"111","servers":{"serverName":"\"Beijing_Base\"","serverIP":"127.0.02"}}

           

方法二

package main

import (
	"encoding/json"
	"fmt"
	"github.com/bitly/go-simplejson"
)
type Auth struct {
	With   string `json:"with"`
	AppKey string
	ReqId  int
	Ts     string
	Sign   string  `json:"sign,omitempty"`
}
type ReqBody struct {
	Td     string `json:"td"` //使用标簽改變Td=》td
	Authen Auth
	Did    string
	Mid    string `json:"mid,omitempty"`//omitempty屬性：如果該字段為nil或0值（數字0,字元串"",空數組[]等），則打包的JSON結果不會有這個字段
}

func main() {
	// 先定義struct變量
	var rb ReqBody
	var auth0 Auth
	//為變量指派
	auth0 = Auth{With: "aa_a", AppKey: "2323", ReqId: 1, Ts: "tttsss"}
	rb = ReqBody{Td: "1111", Authen: auth0, Did: "11101"}
	//修改變量值
	rb.Authen.Sign = "GGGGGGGGGGGGG"
	rb.Td = "222"
	//struct轉json
	c, err := json.Marshal(rb)
	if err != nil {
		fmt.Println("JSON ERR:", err)
	}
	d := string(c)
	fmt.Println(d)
	
	//使用simplejson包可以直接.Get()方法取值（入參為[]byte)
	x, err := simplejson.NewJson([]byte(d))
	re := *x.Get("Did")
	fmt.Println(re)
	
	//寫成方法
	setbody(rb)
}
func setbody(ax interface{}) {
	jm, _ := json.Marshal(ax)
	fmt.Println(string(jm))

}
           

輸出結果

{"td":"222","Authen":{"with":"aa_a","AppKey":"2323","ReqId":1,"Ts":"tttsss","sign":"GGGGGGGGGGGGG"},"Did":"11101"}
{11101}
{"td":"222","Authen":{"with":"aa_a","AppKey":"2323","ReqId":1,"Ts":"tttsss","sign":"GGGGGGGGGGGGG"},"Did":"11101"}
           

二、簡單json轉map

package main
import (
	"encoding/json"
	"fmt"
)
func main() {
	json_str := "{\"IP\": \"127.0.0.1\", \"name\": \"SKY\"}"
	by := []byte(json_str)
	m := make(map[string]string)
	errs := json.Unmarshal(by, &m)
	if errs != nil {
		fmt.Println("Umarshal failed:", errs)
		return
	}
	fmt.Println("m:",m)
	fmt.Println("m.ip:", m["IP"])

}
           

結果如下

m: map[IP:127.0.0.1 name:SKY]
m.ip: 127.0.0.1
           

例二

package main

import (
    "encoding/json"
    "fmt"
)

func main() {
    json_str := "{\"device\": \"1\",\"data\": [{\"humidity\": \"27\",\"time\": \"2017-07-03 15:23:12\"}]}"
    m := make(map[string]interface{})
    err := json.Unmarshal([]byte(json_str), &m)
    fmt.Println(err)
    if err != nil {
        fmt.Println(err)
    } else {
        fmt.Println(m["device"])
        data := m["data"]
        if v, ok := data.([]interface{})[0].(map[string]interface{}); ok {
            fmt.Println(ok, v["humidity"], v["time"])
        }
    }
}
           

執行結果

<nil>
1
true 27 2017-07-03 15:23:12