英文:
Reqwest: read body text and return reqwest::Error
问题
pub async fn print_body() -> Result<(), reqwest::Error> {
let response = reqwest::get("https://www.rust-lang.org").await?;
println!("received text: {:?}", response.text().await?);
response.error_for_status()?;
Ok(())
}
英文:
I want to use reqwest to make a request, then print the response's body and return a reqwest::Error if the status code was >= 400. This is how I would like to do this:
pub async fn print_body() -> Result<(), reqwest::Error> {
let response = reqwest::get("https://www.rust-lang.org").await?;
println!("received text: {:?}", response.text().await?);
response.error_for_status()?;
Ok(())
The trouble is that both response.text() and response.error_for_status() consume the response. Debug printing the response itself or the error from response.error_for_status() does not print the response body.
I've tried saving the status code, then generating a reqwest::Error if the status code is >= 400, but reqwest::Error is not meant to be constructed by library users since its inner field and constructor are private. Ideally a reqwest::Error is returned since other functions depend on this API, and I would like to understand if it's possible to achieve this without changing the public interface.
答案1
得分: 2
你可能忽略了error_for_status_ref()方法，它不会消耗响应。只需要交换调用的顺序：
pub async fn print_body() -> Result<(), reqwest::Error> {
let response = reqwest::get("https://www.rust-lang.org").await?;
response.error_for_status_ref()?;
println!("received text: {:?}", response.text().await?);
Ok(())
}
要始终打印文本，只需存储error_for_status_ref()的结果，并将引用映射到Ok情况，使其为()，以匹配函数的返回类型：
pub async fn print_body() -> Result<(), reqwest::Error> {
let response = reqwest::get("https://www.rust-lang.org").await?;
let result = response.error_for_status_ref().map(|_| ());
println!("received text: {:?}", response.text().await?);
result
}
英文:
You might have glossed over the error_for_status_ref() method, which does not consume the response. You just need to swap the order of the calls:
pub async fn print_body() -> Result<(), reqwest::Error> {
let response = reqwest::get("https://www.rust-lang.org").await?;
response.error_for_status_ref()?;
println!("received text: {:?}", response.text().await?);
Ok(())
}
To print the text regardless, just store the result of error_for_status_ref() and map the reference in the Ok case to be () to match the return type of your function:
pub async fn print_body() -> Result<(), reqwest::Error> {
let response = reqwest::get("https://www.rust-lang.org").await?;
let result = response.error_for_status_ref().map(|_| ());
println!("received text: {:?}", response.text().await?);
result
}
答案2
得分: 2
没有问题，如果你在检索文本之前处理了错误情况，因为error_for_status在一切正常时返回Response：
pub async fn print_body() -> Result<(), reqwest::Error> {
let response = reqwest::get("https://www.rust-lang.org").await?;
println!("received text: {:?}", response.error_for_status()?.text().await?);
Ok(())
}
英文:
There is no issue if you handle your error case before you retreive the text as error_for_status returns the Response if everything is ok:
pub async fn print_body() -> Result<(), reqwest::Error> {
let response = reqwest::get("https://www.rust-lang.org").await?;
println!("received text: {:?}", response.error_for_status()?.text().await?);
Ok(())
}
答案3
得分: 0
谢谢 @cafce25 指出 error_for_status_ref，我最初忽略了它，因为它在 Ok() 时返回对 self 的引用，如果我试图在调用 .text() 后保留完整的结果以供使用，将会给我编译器错误。但使用 .err() 仅提取错误部分可以解决此问题：
pub async fn print_body() -> Result<(), reqwest::Error> {
let response = reqwest::get("https://www.rust-lang.org").await?;
let maybe_err = response.error_for_status_ref().err();
println!("received text: {:?}", response.text().await?);
match maybe_err {
Some(e) => Err(e),
None => Ok(()),
}
}
英文:
Thank you, @cafce25 for pointing me back to error_for_status_ref, which I originally passed over since it returns a reference to self on Ok(), giving me compiler errors if I tried to keep the full result to use after calling .text(). But grabbing just the error with .err() resolves it:
pub async fn print_body() -> Result<(), reqwest::Error> {
let response = reqwest::get("https://www.rust-lang.org").await?;
let maybe_err = response.error_for_status_ref().err();
println!("received text: {:?}", response.text().await?);
match maybe_err {
Some(e) => Err(e),
None => Ok(()),
}
}
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