Go語言處理JSON

    對於簡單JSON的encode是這樣的:

if bs, err := json.Marshal(m);
err != nil {
    panic(err)
}

如何解析比較複雜的JSON串呢?筆者找了一個代碼demo,希望通過demo說清楚go是如何解析的。

package main

import "fmt"
import "encoding/json"

type MxRecords struct {
 Value    string
 Ttl      int
 Priority int
 HostName string
}
type Data struct {
 MxRecords []MxRecords
}
type Response struct {
 Status string `json:"status"`
 Data   Data   `json:"data"`
}
type apiR struct {
 Response Response `json:"response"`
}

func main() {
 body := `{
    "response":
    {
        "status":"SUCCESS",
        "data":
        {
            "mxRecords":
            [
                {
                    "value":"us2.mx3.mailhostbox.com.",
                    "ttl":1,
                    "priority":100,
                    "hostName":"hostname@"
                },
                {
                    "value":"us2.mx1.mailhostbox.com.",
                    "ttl":1,
                    "priority":100, "hostName":"hostnam233e@"
                },
                {
                    "value":"us2.mx2.mailhostbox.com.",
                    "ttl":1,
                    "priority":100,
                    "hostName":"@"
                },
            ],
            "cnameRecords":
            [
                {
                    "aliasHost":"pop.a.co.uk.",
                    "canonicalHost":"us2.pop.mailhostbox.com."},
                {
                    "aliasHost":"webmail.a.co.uk.",
                    "canonicalHost":"us2.webmail.mailhostbox.com."
                },
                {
                    "aliasHost":"smtp.a.co.uk.", "canonicalHost":"us2.smtp.mailhostbox.com."
                },
                {
                    "aliasHost":"imap.a.co.uk.",
                    "canonicalHost":"us2.imap.mailhostbox.com."
                },
            ],
            "dkimTxtRecord":
            {
                "domainname":"20a19._domainkey.a.co.uk",
                "value":"\"v=DKIM1; g=*; k=rsa; p=DkfbhO8Oyy0E1WyUWwIDAQAB\"",
                "ttl":1
            },
            "spfTxtRecord":
            {
                "domainname":"a.co.uk",
                "value":"\"v=spf1 redirect=_spf.mailhostbox.com\"",
                "ttl":1
            },
            "loginUrl":"us2.cp.mailhostbox.com"
        }
    }
}`
 var r apiR
 err := json.Unmarshal([]byte(body), &r)
 if err != nil {
 fmt.Printf("err was %v", err)
}
 // 表示json轉換成struct之後的内部某塊值
 fmt.Println(r.Response.Data.MxRecords[1].HostName)
}

根據以上代碼來看，解析json的思路就是先根據json的實際情況，先定義struct，之後再逐層的根據内部數據類型來處理。