如何使用 reqwest POST 一个文件？

Question

reqwest v0.9.18 的文档显示了以下发布文件的示例：

let file = fs::File::open("from_a_file.txt")?;
let client = reqwest::Client::new();
let res = client.post("http://httpbin.org/post")
    .body(file)
    .send()?;

reqwest v0.11 的最新文档不再包含此示例，尝试构建它失败并在调用 body() 时出现以下错误：

the trait `From<std::fs::File>` is not implemented for `Body`

发送文件的更新方法是什么？

Answer 1

您链接到的具体示例早于 reqwest crate using async. If you want to use that exact example, then instead of reqwest::Client, you need to use reqwest::blocking::Client。这还需要启用 blocking 功能。

明确地说，您实际上仍然可以找到该示例，它只是位于 reqwest::blocking::RequestBuilder's body() 方法的文档中。

// reqwest = { version = "0.11", features = ["blocking"] }
use reqwest::blocking::Client;
use std::fs::File;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let file = File::open("from_a_file.txt")?;

    let client = Client::new();
    let res = client.post("http://httpbin.org/post")
        .body(file)
        .send()?;

    Ok(())
}

另请查看 reqwest 的 Form and RequestBuilder's multipart() method, as there for instance is a file() 方法。

如果你确实想使用异步，那么你可以使用FramedRead from the tokio-util crate. Along with the TryStreamExt trait, from the futures crate。

只需确保为 reqwest 启用 stream 功能，为 tokio-util 启用 codec 功能。

// futures = "0.3"
use futures::stream::TryStreamExt;

// reqwest = { version = "0.11", features = ["stream"] }
use reqwest::{Body, Client};

// tokio = { version = "1.0", features = ["full"] }
use tokio::fs::File;

// tokio-util = { version = "0.6", features = ["codec"] }
use tokio_util::codec::{BytesCodec, FramedRead};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let file = File::open("from_a_file.txt").await?;

    let client = reqwest::Client::new();
    let res = client
        .post("http://httpbin.org/post")
        .body(file_to_body(file))
        .send()
        .await?;

    Ok(())
}

fn file_to_body(file: File) -> Body {
    let stream = FramedRead::new(file, BytesCodec::new());
    let body = Body::wrap_stream(stream);
    body
}

如何使用 reqwest POST 一个文件？

How to POST a file using reqwest?

rust

reqwest