字符集

百分比编码(URL 编码)字符串

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使用 percent-encoding crate 中的 utf8_percent_encode 函数对输入字符串进行百分比编码(URL 编码)。解码使用 percent_decode 函数。

use percent_encoding::{utf8_percent_encode, percent_decode, AsciiSet, CONTROLS}; use std::str::Utf8Error; /// https://url.spec.whatwg.org/#fragment-percent-encode-set const FRAGMENT: &AsciiSet = &CONTROLS.add(b' ').add(b'"').add(b'<').add(b'>').add(b'`'); fn main() -> Result<(), Utf8Error> { let input = "confident, productive systems programming"; let iter = utf8_percent_encode(input, FRAGMENT); let encoded: String = iter.collect(); assert_eq!(encoded, "confident,%20productive%20systems%20programming"); let iter = percent_decode(encoded.as_bytes()); let decoded = iter.decode_utf8()?; assert_eq!(decoded, "confident, productive systems programming"); Ok(()) }

编码集定义哪些字节(除了非 ASCII 字节和控制键之外)需要进行百分比编码(URL 编码),这个集合的选择取决于上下文。例如,url 对 URL 路径中的 ? 编码,而不对查询字符串中的 ? 编码。

编码的返回值是 &str 切片的迭代器,然后聚集为一个字符串 String

将字符串编码为 application/x-www-form-urlencoded

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如下实例使用 form_urlencoded::byte_serialize 将字符串编码为 application/x-www-form-urlencoded 表单语法,随后使用 form_urlencoded::parse 对其进行解码。这两个函数都返回迭代器,然后这些迭代器聚集为 String

use url::form_urlencoded::{byte_serialize, parse}; fn main() { let urlencoded: String = byte_serialize("What is ❤?".as_bytes()).collect(); assert_eq!(urlencoded, "What+is+%E2%9D%A4%3F"); println!("urlencoded:'{}'", urlencoded); let decoded: String = parse(urlencoded.as_bytes()) .map(|(key, val)| [key, val].concat()) .collect(); assert_eq!(decoded, "What is ❤?"); println!("decoded:'{}'", decoded); }

编码和解码十六进制

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data_encoding crate 提供了 HEXUPPER::encode 方法,该方法接受 &[u8] 参数并返回十六进制数据的字符串 String

类似地,data_encoding crate 提供了 HEXUPPER::decode 方法,该方法接受 &[u8] 参数。如果输入数据被成功解码,则返回 Vec<u8>

下面的实例将 &[u8] 数据转换为等效的十六进制数据,然后将此值与预期值进行比较。

use data_encoding::{HEXUPPER, DecodeError}; fn main() -> Result<(), DecodeError> { let original = b"The quick brown fox jumps over the lazy dog."; let expected = "54686520717569636B2062726F776E20666F78206A756D7073206F76\ 657220746865206C617A7920646F672E"; let encoded = HEXUPPER.encode(original); assert_eq!(encoded, expected); let decoded = HEXUPPER.decode(&encoded.into_bytes())?; assert_eq!(&decoded[..], &original[..]); Ok(()) }

编码和解码 base64

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使用 encode 将字节切片编码为 base64 字符串,对 base64 字符串解码使用 decode

use error_chain::error_chain; use std::str; use base64::{encode, decode}; error_chain! { foreign_links { Base64(base64::DecodeError); Utf8Error(str::Utf8Error); } } fn main() -> Result<()> { let hello = b"hello rustaceans"; let encoded = encode(hello); let decoded = decode(&encoded)?; println!("origin: {}", str::from_utf8(hello)?); println!("base64 encoded: {}", encoded); println!("back to origin: {}", str::from_utf8(&decoded)?); Ok(()) }