encoding/base64
四个 Encoding
- StdEncoding：常规编码
- URLEncoding：URL safe 编码
- RawStdEncoding：常规编码，末尾不补 =
- RawURLEncoding：URL safe 编码，末尾不补 =
其中，URL safe 编码，相当于是替换掉字符串中的特殊字符，+ 和 /。更多关于 base64 的信息查看 wiki 和 RFC 4648。
下面是例子：
package main
import (
"encoding/base64"
"fmt"
)
func main() {
msg := []byte("Hello world. 你好，世界！")
encoded := base64.StdEncoding.EncodeToString(msg)
fmt.Println(encoded)
// SGVsbG8gd29ybGQuIOS9oOWlve+8jOS4lueVjO+8gQ==
decoded, _ := base64.StdEncoding.DecodeString(encoded)
fmt.Println(string(decoded))
// Hello world. 你好，世界！
encoded = base64.RawStdEncoding.EncodeToString(msg)
fmt.Println(encoded)
// SGVsbG8gd29ybGQuIOS9oOWlve+8jOS4lueVjO+8gQ
decoded, _ = base64.RawStdEncoding.DecodeString(encoded)
fmt.Println(string(decoded))
// Hello world. 你好，世界！
encoded = base64.URLEncoding.EncodeToString(msg)
fmt.Println(encoded)
// SGVsbG8gd29ybGQuIOS9oOWlve-8jOS4lueVjO-8gQ==
decoded, _ = base64.URLEncoding.DecodeString(encoded)
fmt.Println(string(decoded))
// Hello world. 你好，世界！
encoded = base64.RawURLEncoding.EncodeToString(msg)
fmt.Println(encoded)
// SGVsbG8gd29ybGQuIOS9oOWlve-8jOS4lueVjO-8gQ
decoded, _ = base64.RawURLEncoding.DecodeString(encoded)
fmt.Println(string(decoded))
// Hello world. 你好，世界！
}