使用 Rust 發送 HTTP 請求

Others
,

前言

一般情境下，可以使用 reqwest 套件來發送 HTTP 請求，它是基於提供低階 API 的 hyper 套件的封裝。

做法

使用 reqwest 套件

安裝依賴套件。

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[dependencies]
reqwest = { version = "0.11", features = ["json"] }
serde = { version = "1.0", features = ["derive"] }
tokio = { version = "1", features = ["full"] }

GET

修改 main.rs 檔。

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use serde::{Deserialize, Serialize};
use std::error::Error;

#[derive(Serialize, Deserialize, Debug)]
struct Response {
    origin: String,
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
    let resp = fetch().await?;
    println!("{:#?}", resp);
    Ok(())
}

async fn fetch() -> Result<Response, Box<dyn Error>> {
    let client = reqwest::Client::new();
    let res = client
        .get("https://httpbin.org/ip")
        .send()
        .await?
        .json::<Response>()
        .await?;
    return Ok(res);
}

執行程式。

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cargo run

輸出如下：

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Response {
    origin: "101.10.97.155",
}

POST

修改 main.rs 檔。

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use serde::{Deserialize, Serialize};
use std::{collections::HashMap, error::Error};

#[derive(Serialize, Deserialize, Debug)]
struct Response {
    json: HashMap<String, String>,
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
    let resp = fetch().await?;
    println!("{:#?}", resp);
    Ok(())
}

async fn fetch() -> Result<Response, Box<dyn Error>> {
    let mut map = HashMap::new();
    map.insert("lang", "rust");
    map.insert("body", "json");
    let client = reqwest::Client::new();
    let res = client
        .post("https://httpbin.org/anything")
        .json(&map)
        .send()
        .await?
        .json::<Response>()
        .await?;
    return Ok(res);
}

執行程式。

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cargo run

輸出如下：

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Response {
    json: {
        "lang": "rust",
        "body": "json",
    },
}

使用 hyper 套件

安裝依賴套件。

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[dependencies]
hyper = { version = "0.14", features = ["full"] }
tokio = { version = "1", features = ["full"] }

修改 main.rs 檔。

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use hyper::{Client, Uri};
use std::str;

type Result<T> = std::result::Result<T, Box<dyn std::error::Error + Send + Sync>>;

#[tokio::main]
async fn main() -> Result<()> {
    let client = Client::new();
    let uri = Uri::from_static("http://httpbin.org/ip");
    let mut res = client.get(uri).await?;

    println!("status code: {}", res.status());
    for (key, value) in res.headers().iter() {
        println!("{}: {}", key, value.to_str().unwrap())
    }

    let body = res.body_mut();
    let buf = hyper::body::to_bytes(body).await?;
    let content = str::from_utf8(buf.as_ref())?;
    println!("{}", content);

    Ok(())
}

執行程式。

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cargo run

輸出如下：

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status code: 200 OK
date: Mon, 05 Dec 2022 15:09:59 GMT
content-type: application/json
content-length: 32
connection: keep-alive
server: gunicorn/19.9.0
access-control-allow-origin: *
access-control-allow-credentials: true
{
  "origin": "101.10.97.155"
}

參考資料