rust - 使用 serde_json 将 JSON 对象转换为 HashMap

Question

我正在尝试使用 serde_json 将 JSON 对象解析为 Rust 中的 HashMap。使用以下代码，我得到了错误:

error[E0507]: cannot move out of index of `Value`

如何将 Value 放入我的 HashMap？

use serde_json::{Result, Value};
use std::collections::HashMap;

fn main() {

  let variables_json = r#"{
    "awayTeamAbbrev": "DAL",
    "homeTeamAbbrev": "TB",
    "gameInstanceUid": "cbs-nfl-pickem-challenge",
    "sportType": "NFL",
    "weekNumber": 1
  }"#;
  let keys = vec!["sportType","weekNumber"];
  dbg!(json_to_hashmap(&variables_json, keys));
    
}  

fn json_to_hashmap(json: &str, keys: Vec<&str>) -> Result<HashMap<String, Value>> {
    let lookup: Value = serde_json::from_str(json).unwrap();
    let mut map = HashMap::new();
    for key in keys {
        let varname = key.to_owned();
        let value = lookup[&varname];
        map.insert(varname, value);
    }
    Ok(map)

}

Answer 1

您可以获得 HashMap<String, Value>直接来自 serde_json::from_str ，然后使用 remove_entry在不克隆的情况下取出值:

fn json_to_hashmap(json: &str, keys: Vec<&str>) -> Result<HashMap<String, Value>> {
    let mut lookup: HashMap<String, Value> = serde_json::from_str(json).unwrap();
    let mut map = HashMap::new();
    for key in keys {
        let (k, v) = lookup.remove_entry (key).unwrap();
        map.insert(k, v);
    }
    Ok(map)
}

Playground