go 生成随机字符串
func GetRandomString(l int) string {
str := "0123456789abcdefghijklmnopqrstuvwxyz"
bytes := []byte(str)
result := []byte{}
r := rand.New(rand.NewSource(time.Now().UnixNano()))
for i := 0; i \< l; i++ {
result = append(result, bytes[r.Intn(len(bytes))])
}
return string(result)
}