在`Result<reqwest::blocking::Response，reqwest::Error>`中找不到锈蚀- json方法

Question

我想使用reqwest，但我不能--我有一个错误：

let users: Vec<User> = response.json();
                                ^^^^ method not found in `Result<reqwest::blocking::Response, reqwest::Error>

这是我的密码：

use reqwest::Error;
use tokio;

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


#[tokio::main]
pub fn main() {

    let request_url = format!("https://api.ipify.org");
    println!("{}", request_url);
    let response = reqwest::blocking::get(&request_url);

    let users: Vec<User> = response.json();
    println!("{:?}", users);
}

我的依赖关系：

[dependencies]
serde = { version = "1.0.136", features = ["derive"]}
reqwest = { version = "0.11.9", features = ["blocking", "json"]}
tokio = { version = "1.17.0", features = ["full"] }

为什么会发生这种事？我该怎么做才能解决这个问题？

Answer 1

reqwest::blocking::get()返回一个reqwest::Result<Response>，它是内置Result类型的别名。Result表示一个可能失败的操作，因此您不一定有响应--您可能会有一个错误。

您需要使用?运算符将错误从函数中传播出去，也可以使用match或if let来展开值。

例如，使用match

let response = match reqwest::blocking::get(&request_url) {
    // Unwraps the response value from the Result
    Ok(r) => r,

    // Unwraps the error from the Result and terminates main()
    Err(err) => {
        println!("Request failed: {}", err.to_string());
        return;
    },
};

进一步读：

• Recoverable Errors with Result