go语言生成json格式的文件

import (
"encoding/json"
"fmt"
"io/ioutil"
"os"
)
type ColorGroup struct {
ID     int
Name   string
Colors []string
}
func main() {
group := ColorGroup{
ID:     1,
Name:   "Reds",
Colors: []string{"Crimson", "Red", "Ruby", "Maroon"},
}
b, err := json.Marshal(group)
if err != nil {
fmt.Println("error:", err)
}
//生成json文件
err = ioutil.WriteFile("test.json", b, os.ModeAppend)
if err != nil {
return
}
var data interface{}
err = json.Unmarshal(b, &data)
if err != nil {
fmt.Println("error:", err)
}
fmt.Println("data", data)  //map[ID:1 Name:Reds Colors:[Crimson Red Ruby Maroon]]
dataJson := data.(map[string]interface{})["Colors"]
fmt.Println("dataJson", dataJson)  //[Crimson Red Ruby Maroon]
b11, err := json.Marshal(dataJson)
if err != nil {
fmt.Println("error:", err)
}
err = ioutil.WriteFile("test11.json", b11, os.ModeAppend)
if err != nil {
return
}
}