尝试使用Serde反序列化对象数组时，“无效类型：映射，预期为序列”

Question

我正在尝试使用Serde编写API包装器。尝试运行程序时出现此错误：

Err(Error { kind: Json(Error("invalid type: map, expected a sequence", line: 1, column: 2)), url: None })

听起来好像Serde遇到{，根据我当前模型的设置方式，它期望[，但也许我对这种理论不太了解。

直接从端点返回的JSON是：

[
  {
    "title": "Pad Abort Test",
    "event_date_utc": "2015-05-06T13:00:00Z",
    "event_date_unix": 1430917200,
    "flight_number": null,
    "details": "Crew Dragon tests launch abort system, which can provide astronauts with escape capability all the way to orbit.",
    "links": {
      "reddit": "https:\/\/www.reddit.com\/r\/spacex\/comments\/3527zv\/official_video_pad_abort_test_2015\/",
      "article": "https:\/\/spaceflightnow.com\/2015\/04\/21\/dragon-pad-abort-test-set-for-early-may\/",
      "wikipedia": "https:\/\/en.wikipedia.org\/wiki\/Pad_abort_test"
    }
  },
  {
    "title": "SpaceX Awarded Commercial Crew Contract",
    "event_date_utc": "2014-09-16T01:00:00Z",
    "event_date_unix": 1410829200,
    "flight_number": null,
    "details": "NASA awards $2.6 billion SpaceX contract to fly American astronauts.",
    "links": {
      "reddit": null,
      "article": "https:\/\/www.washingtonpost.com\/news\/the-switch\/wp\/2014\/09\/16\/nasa-awards-space-contract-to-boeing-and-spacex\/?utm_term=.d6388390d071",
      "wikipedia": null
    }
  }
]

我知道我的代码是错误的-我只是不知道如何解决它。在这里：

models.rs

#[derive(Debug, Deserialize)]
pub struct HistoricalEvents {
    items: Vec<HistoricalEvent>,
}

#[derive(Debug, Deserialize)]
pub struct HistoricalEvent {
    title: String,
    event_date_utc: String,
    event_date_unix: u64,
    flight_number: Option<u32>,
    details: Option<String>,
    links: Links,
}

#[derive(Debug, Deserialize)]
struct Links {
    reddit: Option<String>,
    article: Option<String>,
    wikipedia: Option<String>,
}

lib.rs

的一部分

pub fn history(
    start_date: Option<String>,
    end_date: Option<String>,
    flight_number: Option<u32>,
    sort_dir: Option<SortDir>,
) -> Result<HistoricalEvents, failure::Error> {
    let mut params = HashMap::new();

    start_date.and_then(|string| params.insert("start", string));

    end_date.and_then(|string| params.insert("end", string));

    flight_number.and_then(|num| params.insert("flight_number", num.to_string()));

    sort_dir.and_then(|dir| params.insert("order", dir.to_string()));

    return send_request("info/history", Some(params));
}

fn send_request<T>(
    endpoint: &str,
    params: Option<HashMap<&str, String>>,
) -> Result<T, failure::Error>
where
    T: DeserializeOwned,
{
    let base = &("https://api.spacexdata.com/v2/".to_owned() + endpoint);
    let url = match params {
        Some(map) => Url::parse_with_params(base, map),
        None => Url::parse(base),
    };
    let client = Client::new();
    let mut request = client.get(url.unwrap().as_str());
    let mut response = request.send()?;
    Ok(response.json()?)
}