将json字符串解组为具有结构本身的一个元素的结构 [英] Unmarshal json string to a struct that have one element of the struct itself
问题描述
[{
db:{
url:mongodb:// localhost,
port:27000,
uname:,
pass:,
authdb:,
replicas:[
{
rs01:{
url:mongodb:// localhost,,
port:27001,
uname:,
pass:,
authdb:
}
$ brs02:{
url:mongodb:// localhost,
port:27002,
uname:,
pass:,
authdb:
}
}
]
}
$]
这里是struct
type DBS struct {
URL字符串`json:url`
端口字符串`json:port`
Uname string`json:uname`
传递字符串`json:pass`
Authdb字符串`json:authdb`
副本[] DBS`json:replicas`
}
这里是函数
func loadConfigs( )[] DBS {
var config [] DBS
raw,err:= ioutil.ReadFile(./ config.json)
if err!= nil {
fmt .Println(err.Error())
os.Exit(1)
}
json.Unmarshal(raw,& config)
return config
$ b $ / code>
该函数返回
{[]}
您的JSON输入不是 DBS
的片段,因为还有另一个JSON对象包装器,并且值 DBS
属于属性db
。
replicaps
是一个带有不同键的对象的JSON数组,其值可由 DBS
表示。
因此,要充分描述您的JSON,您需要某种动态类型。例如,一个映射就是这样一个动态类型。因此,您的原始JSON输入可以用类型完全建模: [] map [string] DBS
。这是一部分地图,因为您的JSON输入包含JSON数组。 map键可以为任何属性名称建模,并且该值是由 DBS
结构建模的JSON对象。
查看这个完全解析JSON输入的例子:
type DBS struct {
URL字符串`json:url
端口字符串`json:port`
Unname字符串`json:uname`
传递字符串`json:pass`
Authdb字符串`json: authdb`
Replicas [] map [string] DBS`json:replicas`
}
func main(){
var dbs [] map [string] DBS
if err:= json.Unmarshal([] byte(src),& dbs); err!= nil {
panic(err)
}
fmt.Printf(%+ v,dbs)
}
请注意正确的 json:url)。
p>输出(在去游乐场试试):
[map [db:{URL:mongodb:// localhost Port:27000 Uname:Pass:Authdb:Replicas:[map [rs01:{URL:mongodb:// localhost Port:27001 Uname:Pass:Authdb:Replicas:[]}] map [rs02:{URL:mongodb:// localhost Port:27002 Uname:Pass:Authdb:Replicas:[]}]]}]]
$ b
请注意,您可以进一步建模始终为db
的第一个级别,并且我们可以切换到指针(我在第一个例子中使用了非指针,因此打印的结果是可读的):
type DBReplicated struct {
DB * DBS`json:db`
}
type DBS struct {
URL字符串`json:url`
端口字符串`json:port`
Uname字符串`json:uname`
Pass字符串`json:pass`
Authdb字符串`json:authdb`
副本[] map [string] * DBS`json:replicas`
}
func main(){
var dbs [] * DBReplicated
if err:= json.Unmarshal([] byte(src),& dbs); err!= nil {
panic(err)
}
db:= dbs [0] .DB
fmt.Printf(%+ v \ n ,db)
for _,dbs:= range db.Replicas {
for name,replica:= range dbs {
fmt.Printf(%s:%+ v \\\
,name,replica)
}
}
}
输出(在去游乐场试试):
& {URL:mongodb:// localhost端口:27000 Uname:Pass:Authdb:Replicas:[map [rs01:0x10538200] map [rs02:0x10538240]]}
rs01:& {URL:mongodb:// localhost Port:27001 Uname:Pass:Authdb:Replicas:[]}
rs02:& {URL:mongodb:// localhost端口:27002 Uname :Pass:Authdb:Replicas:[]}
I am go beginner and trying to unmarshal the following json string
[{
"db": {
"url": "mongodb://localhost",
"port": "27000",
"uname": "",
"pass": "",
"authdb": "",
"replicas": [
{
"rs01": {
"url":"mongodb://localhost",
"port": "27001",
"uname": "",
"pass": "",
"authdb": ""
}
},
{
"rs02": {
"url":"mongodb://localhost",
"port": "27002",
"uname": "",
"pass": "",
"authdb": ""
}
}
]
}
}]
here is the struct
type DBS struct {
URL string `json:url`
Port string `json:port`
Uname string `json:uname`
Pass string `json:pass`
Authdb string `json:authdb`
Replicas []DBS `json:replicas`
}
and here is the function
func loadConfigs() []DBS {
var config []DBS
raw, err := ioutil.ReadFile("./config.json")
if err != nil {
fmt.Println(err.Error())
os.Exit(1)
}
json.Unmarshal(raw, &config)
return config
}
The function is returning
{ []}
Your JSON input is not a slice of DBS
, as there is another JSON object wrapper, and a value of DBS
belongs to the property "db"
.
Going deeper, the "replicaps"
is a JSON array with objects holding varying keys, their values being representable by DBS
.
So to fully describe your JSON, you need some kind of "dynamic" type. A map is such a dynamic type for example.
So your original JSON input can be fully modeled with the type: []map[string]DBS
. It's a slice of maps, as your JSON input contains a JSON array. And the map key can model any property name, and the value is a JSON object modeled by the DBS
struct.
See this example which fully parses the JSON input:
type DBS struct {
URL string `json:"url"`
Port string `json:"port"`
Uname string `json:"uname"`
Pass string `json:"pass"`
Authdb string `json:"authdb"`
Replicas []map[string]DBS `json:"replicas"`
}
func main() {
var dbs []map[string]DBS
if err := json.Unmarshal([]byte(src), &dbs); err != nil {
panic(err)
}
fmt.Printf("%+v", dbs)
}
Note the proper tag syntax (e.g. json:"url"
).
Output (try it on the Go Playground):
[map[db:{URL:mongodb://localhost Port:27000 Uname: Pass: Authdb: Replicas:[map[rs01:{URL:mongodb://localhost Port:27001 Uname: Pass: Authdb: Replicas:[]}] map[rs02:{URL:mongodb://localhost Port:27002 Uname: Pass: Authdb: Replicas:[]}]]}]]
Note that you can further model the first level which is always "db"
, and we can switch to pointers (I used non-pointers in the first example so the printed result is readable):
type DBReplicated struct {
DB *DBS `json:"db"`
}
type DBS struct {
URL string `json:"url"`
Port string `json:"port"`
Uname string `json:"uname"`
Pass string `json:"pass"`
Authdb string `json:"authdb"`
Replicas []map[string]*DBS `json:"replicas"`
}
func main() {
var dbs []*DBReplicated
if err := json.Unmarshal([]byte(src), &dbs); err != nil {
panic(err)
}
db := dbs[0].DB
fmt.Printf("%+v\n", db)
for _, dbs := range db.Replicas {
for name, replica := range dbs {
fmt.Printf("%s: %+v\n", name, replica)
}
}
}
Output (try it on the Go Playground):
&{URL:mongodb://localhost Port:27000 Uname: Pass: Authdb: Replicas:[map[rs01:0x10538200] map[rs02:0x10538240]]}
rs01: &{URL:mongodb://localhost Port:27001 Uname: Pass: Authdb: Replicas:[]}
rs02: &{URL:mongodb://localhost Port:27002 Uname: Pass: Authdb: Replicas:[]}
这篇关于将json字符串解组为具有结构本身的一个元素的结构的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!