Golang json.Unmarshal 未按预期工作

Question

我正在尝试解组来自 vcenter rest api 的 json 响应。当简单地打印响应正文时，它看起来像下面的 o/p

{"value":[{"memory_size_MiB":16384,"vm":"vm-10236","name":"Normal_Windows_192.168.1.10","power_state":"POWERED_OFF","cpu_count":8},{"memory_size_MiB":8192,"vm":"vm-10238","name":"Normal_Windows_192.168.1.11","power_state":"POWERED_OFF","cpu_count":4}]}

我已经导出了结构和结构字段，但是像 memory_size_MiB、power_state、cpu_count 这样的字段没有被解组。打印结构时，它如下所示：-

{Value:[{Mem:0 Vm:vm-10236 Name:Normal_Windows_192.168.1.10 Powerstat: Cpu:0} {Mem:0 Vm:vm-10238 Name:Normal_Windows_192.168.1.11 Powerstat: Cpu:0} {Mem:0 Vm:vm-10582 Name:Normal_Windows_192.168.1.12 Powerstat: Cpu:0}]}%

下面是我的main.go

    package main
    
    import (
...
    )
    type SessionData struct {
        VmwareApiSessionId string `json:"value"`
    }
    //{"memory_size_MiB":16384,"vm":"vm-10236","name":"Normal_Windows_192.168.19.100","power_state":"POWERED_OFF","cpu_count":8}
    type Vm struct {
        Mem int `json: "memory_size_MiB"`
        Vm string `json: "vm"`
        Name string `json: "name"`
        Powerstat string `json: "power_state"`
        Cpu int `json: "cpu_count"`
    }
    //{Value:[{Mem:0 Vm:vm-10236 Name:Normal_Windows_192.168.1.10 Powerstat: Cpu:0} {Mem:0 Vm:vm-10238 Name:Normal_Windows_192.168.1.11 Powerstat: Cpu:0} {Mem:0 Vm:vm-10582 Name:Normal_Windows_192.168.1.12 Powerstat: Cpu:0}]}
    type ColVmList struct {
        Value []Vm `json: "value"`
    }
    func getVmList(sessid string,cli *http.Client) ColVmList {
        vms := ColVmList{}
        req,err:=http.NewRequest("GET","https://sandbox.vmware.local/rest/vcenter/vm",nil)
        req.Header.Add("vmware-api-session-id",sessid)
        resp,err := cli.Do(req)
        if err != nil {
            log.Fatal("Error %s", err)
        }
        defer resp.Body.Close()
        body, err := ioutil.ReadAll(resp.Body)
        fmt.Println(string(body))
        err = json.Unmarshal([]byte(body),&vms)
        if err != nil {
            log.Fatal("error %s", err)
        }
        return vms
    }
    
    func main(){
    //authpart
    loginurl = "https://sandbox.vmware.local/rest/com/vmware/cis/session"
    //login...
    err = json.Unmarshal([]byte(string(body)),&sessVal)
    if  err != nil{
        log.Fatal(err)
    }
    var allvmlist ColVmList
    allvmlist = getVmList(sessVal.VmwareApiSessionId,&cli)
    fmt.Printf("%v",allvmlist)
    }

Answer 1

您的结构标签格式不正确。删除结构标签中 json: 和字符串 "..." 之间的 space。即它必须是 json:"..." 而不是 json: "...".

有些字段即使没有 well-formed 结构标签也能正确解组的原因是字段的名称与 json 属性名称相匹配。

func main() {
    data := []byte(`{"memory_size_MiB":16384}`)

    var obj1 struct {
        Mem int `json: "memory_size_MiB"`
    }
    if err := json.Unmarshal(data, &obj1); err != nil {
        panic(err)
    }
    fmt.Println(obj1)

    var obj2 struct {
        Mem int `json:"memory_size_MiB"`
    }
    if err := json.Unmarshal(data, &obj2); err != nil {
        panic(err)
    }
    fmt.Println(obj2)
}

https://go.dev/play/p/gUR5ed2n0D1

Golang json.Unmarshal 未按预期工作

Golang json.Unmarshal is not working as expected

json

go