golang读取json配置文件

package main

import (
    "fmt"
    "log"
    "os"
    "sync"
    "strings"
    "io/ioutil"
    "encoding/json"
)

type demo struct {
}

type creStruct struct {
    Name string `json:"name"`
    Ak   string `json:"ak"`
    Sk   string `json:"sk"`
}

type cre struct {
    Cres []creStruct `json:"credentials"`
}

func Newdemo() *demo {
    dem := &demo{}

    return dem
}

var wg sync.WaitGroup

func (d *demo) LoadCredentials(path string) cre{
    jsonFile, err := os.Open(path)
    if err != nil {
        log.Println(err)
    }
    defer jsonFile.Close()

    byteValue, err := ioutil.ReadAll(jsonFile)
    if err != nil {
        log.Println(err)
    }

    var cres cre
    err = json.Unmarshal(byteValue, &cres)
    if err != nil {
        log.Println(err)
    }

    data, err := json.MarshalIndent(cres, "", "    ")
    if err != nil {
        log.Println(err)
    }
    fmt.Printf("%s
", data)
    return cres
}

func (d *demo) PrintCredential(cres cre) {
    wg.Add(len(cres.Cres))

    for _, i := range cres.Cres {
        go func(email, ak, sk string) {
            defer wg.Done()

            name := strings.Split(email, "@")
            fmt.Printf("name: %s, ak: %s, sk: %s
", name[0], ak, sk)
        }(i.Name, i.Ak, i.Sk)
    }
}

func init() {
    f, err := os.OpenFile("goerror.log", os.O_APPEND | os.O_CREATE | os.O_RDWR, 0666)
    if err != nil {
        log.Fatal(err)
    }
    log.SetPrefix("Trace: ")
    log.SetOutput(f)
}

func main() {
    mydemo := Newdemo()

    val := mydemo.LoadCredentials("/root/goProj/credential.json")

    mydemo.PrintCredential(val)

    wg.Wait()
}

{
    "credentials": [
        {
            "name": "********@.onaliyun.com",
            "ak":   "********",
            "sk":   "********"
        },
        {
            "name": "********@.onaliyun.com",
            "ak": "********",
            "sk": "********"
        }
    ]
}

• Use WaitGroup.Add(int) to keep count of how many goroutines we will be running as part of our logic.
• Use WaitGroup.Done() to signal that a goroutine is done with its task.
• Use WaitGroup.Wait() to wait until all goroutines are done.
• Pass WaitGroup instance to the goroutines so they can call the Done() method.