Serde适配器，用于控制字节的表现形式

人类可读的格式通常不包含表示任意二进制数据的一致方法，这意味着那些serde库最终可能会使用一种不适合所有用途的serde的"字节"类型的表示。

// [dependencies]
// serde = { version = "1.0", features = ["derive"] }
// serde_bytes = "0.11"
// serde_json = "1.0"
// serde_yaml = "0.8"
// toml = "0.5"

use serde::Serialize;

#[derive(Serialize)]
struct Demo {
    #[serde(with = "serde_bytes")]
    bytes: Vec<u8>,
}

fn main() {
    let bytes = b"testing".to_vec();
    let s = Demo { bytes };

    println!("JSON: {}", serde_json::to_string(&s).unwrap());
    println!("YAML: {}", serde_yaml::to_string(&s).unwrap());
    println!("TOML: {}", toml::to_string(&s).unwrap());
}

JSON: {"bytes":[116,101,115,116,105,110,103]}
YAML: ---
bytes:
  - 116
  - 101
  - 115
  - 116
  - 105
  - 110
  - 103
TOML: bytes = [116, 101, 115, 116, 105, 110, 103]

此适配器允许您通过包装类似于以下这样的序列化器来控制字节的表现形式

#[derive(Serialize, Deserialize)]
struct Demo {
    #[serde(with = "serde_bytes")]
    bytes: Vec<u8>,
}

fn main() {
    let bytes = b"testing".to_vec();
    let demo = Demo { bytes };

    let mut out = vec![];
    let mut ser = serde_json::Serializer::new(&mut out);
    let base64_config = base64::Config::new(base64::CharacterSet::UrlSafe, true);
    let ser = BytesRepr::base64(&mut ser, base64_config);
    demo.serialize(ser).unwrap();

    let serialized = String::from_utf8(out).unwrap();
    println!("JSON(base64): {}", serialized);
}

输出

JSON(base64): {"bytes":"dGVzdGluZw=="}