JSON格式转换

读取json格式文件：

b, err := ioutil.ReadFile("./PermissionData/systemPermissionData.json")
    if err != nil {
        ctx.Error(errors.New("file not found"))
    }
    var resp interface{}
    jsoniter.Unmarshal(b, &resp)

1、map映射类型--->> JSON ：

var toJson map[string]string
toJson = map[string]string{
    "k1":"v1",
    "k2":"v2",
}
data, err := json.MarshalIndent(toJson, "", "    ")
if err != nil {
    log.Fatalf("JSON marshaling failed: %s", err)
}
fmt.Printf("%s
", data)

结果：

{
    "k1": "v1",
    "k2": "v2"
}

2、struct结构体类型 --->>  JSON :

var toJson struct{
    Name string
    Age int
}
toJson.Name = "kitty"
toJson.Age = 3

data, err := json.MarshalIndent(toJson, "", "    ")
if err != nil {
    log.Fatalf("JSON marshaling failed: %s", err)
}
fmt.Printf("%s
", data)

结果：

{
    "Name": "kitty",
    "Age": 3
}

3、[]slice切片类型 ---->> JSON :

var toJson = []string{"str1", "str2","...",}


data, err := json.MarshalIndent(toJson, "", "    ")
if err != nil {
    log.Fatalf("JSON marshaling failed: %s", err)
}
fmt.Printf("%s
", data)

结果：

[
    "str1",
    "str2",
    "..."
]

==========

3、[]slice里面嵌套map类型

var toJson = []map[string]string{
    {"k1":"v1", "k2":"v2"},
    {"k3":"v3", "k4":"v4"},
}


data, err := json.MarshalIndent(toJson, "", "    ")
if err != nil {
    log.Fatalf("JSON marshaling failed: %s", err)
}
fmt.Printf("%s
", data)

结果：

[
    {
        "k1": "v1",
        "k2": "v2"
    },
    {
        "k3": "v3",
        "k4": "v4"
    }
]

4、[]slice里面嵌套struct结构体：

type User struct {
    Name string
    Age int
}

var user1 = &User{
    Name:"kitty",
    Age:11,
}
var user2 = &User{
    Name:"kitty",
    Age:11,
}

var toJson = []*User{
    user1,
    user2,
}


data, err := json.MarshalIndent(toJson, "", "    ")
if err != nil {
    log.Fatalf("JSON marshaling failed: %s", err)
}
fmt.Printf("%s
", data)

结果：

[
    {
        "Name": "kitty",
        "Age": 11
    },
    {
        "Name": "kitty",
        "Age": 11
    }
]

5、多级嵌套：

type Address struct {
    Address string
}

type User struct {
    Name string
    Age int
    Addr *Address
}

var user1 = &User{
    Name:"kitty",
    Age:11,
    Addr:&Address{
        Address:"beijing",
    },
}
var user2 = &User{
    Name:"Masha",
    Age:18,
    Addr:&Address{
        Address:"shanghai",
    },
}

var toJson = []*User{
    user1,
    user2,
}


data, err := json.MarshalIndent(toJson, "", "    ")
if err != nil {
    log.Fatalf("JSON marshaling failed: %s", err)
}
fmt.Printf("%s
", data)

结果：

[
    {
        "Name": "kitty",
        "Age": 11,
        "Addr": {
            "Address": "beijing"
        }
    },
    {
        "Name": "Masha",
        "Age": 18,
        "Addr": {
            "Address": "shanghai"
        }
    }
]