怎样用Golang解析复杂JSON配置文件 介绍stream解码与结构体标签技巧

{"name": "log1", "level": "info"}
{"name": "log2", "level": "debug"}

file, _ := os.Open("logs.json")
defer file.Close()

decoder := json.NewDecoder(file)
for {
    var log map[string]string
    if err := decoder.Decode(&log); err != nil {
        break
    }
    fmt.Println(log["name"], log["level"])
}

var data map[string]interface{}
decoder.Decode(&data)

for k, v := range data {
    switch v := v.(type) {
    case string:
        fmt.Printf("%s is string: %s\n", k, v)
    case float64:
        fmt.Printf("%s is number: %v\n", k, v)
    }
}

{
  "server": {
    "host": "localhost",
    "port": 8080
  },
  "timeout": "30s"
}

type Config struct {
    Server struct {
        Host string `json:"host"`
        Port int    `json:"port"`
    } `json:"server"`
    Timeout string `json:"timeout"`
}

FieldOne string `json:"field_one"` // 匹配"field_one"
FieldTwo string `json:"fieldTwo"`  // 匹配"fieldTwo"

type Option struct {
    Debug   *bool   `json:"debug,omitempty"`
    Retries *int    `json:"retries,omitempty"`
}

if opt.Debug == nil {
    defaultDebug := true
    opt.Debug = &defaultDebug
}