Json 使用Serde反序列化跳过序列中的无效元素
使用Serde,我希望通过保留有效元素并跳过无效元素来反序列化元素序列 我有以下有效载荷:Json 使用Serde反序列化跳过序列中的无效元素,json,rust,deserialization,serde,Json,Rust,Deserialization,Serde,使用Serde,我希望通过保留有效元素并跳过无效元素来反序列化元素序列 我有以下有效载荷: { "nhits": 30, "parameters": { "dataset": "occupation-parkings-temps-reel", "timezone": "UTC", "rows":
{
"nhits": 30,
"parameters": {
"dataset": "occupation-parkings-temps-reel",
"timezone": "UTC",
"rows": 50,
"start": 0,
"format": "json",
"facet": [
"etat_descriptif"
]
},
"records": [
{
"datasetid": "occupation-parkings-temps-reel",
"recordid": "1436c55a76fc7910b5a0336eb74cc0957870a8fd",
"fields": {
"nom_parking": "P1 Esplanade - Centre commercial",
"etat": 1,
"ident": 27,
"infousager": "220",
"idsurfs": "1703_DEP_27",
"libre": 229,
"total": 251,
"etat_descriptif": "Ouvert"
},
"record_timestamp": "2020-12-20T12:51:00.704000+00:00"
},
{
"datasetid": "occupation-parkings-temps-reel",
"recordid": "2b15689c04478fcad8c964a5d9f3c0148eb70126",
"fields": {
"etat": 1,
"ident": 30,
"infousager": "LIBRE",
"libre": 719,
"total": 719,
"etat_descriptif": "Ouvert"
},
"record_timestamp": "2020-12-20T12:51:00.704000+00:00"
}
],
"facet_groups": [
{
"facets": [
{
"count": 28,
"path": "Ouvert",
"state": "displayed",
"name": "Ouvert"
},
{
"count": 1,
"path": "Ferm\u00e9",
"state": "displayed",
"name": "Ferm\u00e9"
},
{
"count": 1,
"path": "frequentation temps reel indisponible",
"state": "displayed",
"name": "frequentation temps reel indisponible"
}
],
"name": "etat_descriptif"
}
]
}
我有一个不同的对应结构:
/// The container for the API response
#[derive(Debug, Deserialize)]
pub struct OpenDataResponse<T> {
/// The parameters relative to the response
pub parameters: Parameters,
/// The parameters relative to the pagination
#[serde(flatten)]
pub pagination: Pagination,
/// The sets of records inside the response
#[serde(bound(deserialize = "T: Deserialize<'de>"))]
#[serde(deserialize_with = "deserialize::failable_records")]
pub records: Vec<Record<T>>,
}
/// A record represents an item of some data
/// with a specific id.
#[derive(Debug, Deserialize)]
pub struct Record<T> {
/// The identifier of the record
#[serde(rename(deserialize = "recordid"))]
pub id: String,
#[serde(rename(deserialize = "fields"))]
pub(crate) inner: T,
}
#[derive(Debug, Deserialize)]
pub struct StatusOpenData {
#[serde(rename(deserialize = "idsurfs"))]
pub id: String,
#[serde(rename(deserialize = "nom_parking"))]
pub name: String,
#[serde(rename(deserialize = "etat"))]
pub status: i8,
#[serde(rename(deserialize = "libre"))]
pub free: u16,
pub total: u16,
#[serde(rename(deserialize = "etat_descriptif"))]
pub users_info: Option<String>,
}
此操作失败,出现了一些错误,如:应将错误考虑在内:错误(“预期的,或]”,
我不理解返回错误的原因:
let elements:Vec=Deserialize::Deserialize(反序列化器);
尝试对一系列FailableDeserialize
元素进行反序列化,但这种类型以一种他不能返回错误的方式实现了反序列化
我错在哪里?用ok()
忽略错误的简单方法将导致反序列化程序的去同步。
反序列化错误可以发生在任何令牌上,并且不需要仅在使用完整元素后发生。
如果反序列化记录
失败,serde将卡在记录
对象内,但Vec
反序列化器需要一个它找不到的,
如果您坚持使用现有的板条箱,而这些板条箱已经提供了类似于您的FailableDeserialize
的功能,那么就更容易了。
您可以使用以下方式写入故障记录:
fn可故障的\u记录,
T:反序列化“)]
结构包装器(#[serde_as(反序列化_as=“Vec”)]Vec);
//从下面的行返回错误
let元素:包装器=反序列化::反序列化(反序列化器)?;
让result=elements.0.into_iter().filter_map(| f | f).collect();
好(结果)
}
在内部,它使用一个未标记的枚举来解决去同步问题,因为这将在开始真正的反序列化之前消耗一个完整的对象。您是否可以列出一个失败的示例?
struct FailableDeserialize<T> {
inner: Option<T>,
}
impl<'de, T: Deserialize<'de>> Deserialize<'de> for FailableDeserialize<T> {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
let value: Option<T> = Deserialize::deserialize(deserializer).ok();
Ok(FailableDeserialize { inner: value })
}
}
pub(super) fn failable_records<'de, D, T>(deserializer: D) -> Result<Vec<T>, D::Error>
where
D: Deserializer<'de>,
T: Deserialize<'de>,
{
// Error returned from the line below
let elements: Vec<FailableDeserialize<T>> = Deserialize::deserialize(deserializer)?;
let result = elements.into_iter().filter_map(|f| f.inner).collect();
Ok(result)
}