[英]JsLookup on multiple level array using play Json library (or any other suggestion)
我的函數正在接收一個JsValue
,現在這個 json 有列表,這個列表元素也可以是列表,例如:
{
"firstName": "Elon",
"lastName": "Musk",
"companies": [
{
"name": "Tesla",
"city": "San Francisco",
"offices": ["sf", "ny"],
"management": {
"loscation": "New York",
"boardMembers": [
{
"name": "John",
"age": 45
},
{
"name": "Mike",
"age": 55
},
{
"name": "Rebecca",
"age": 35
}
]
}
},
{
"name": "SpaceX",
"city": "San Francisco",
"offices": ["la", "ta"],
"management": {
"loscation": "San Mateo",
"boardMembers": [
{
"name": "Lisa",
"age": 45
},
{
"name": "Dan",
"age": 55
},
{
"name": "Henry",
"age": 35
}
]
}
}
]
}
所以一個公司有管理對象,其中有 boardMembers 列表。
我的函數正在接收該元素的路徑,例如:
companies[*].management.boardMembers[*].name
我希望它返回一個包含此對象所有元素的列表,因此結果將是:
["John", "Mike", "Rebecca", "Lisa", "Dan", "Henry"]
這有點復雜,但我認為play.api.libs.json._
可能會有一些play.api.libs.json._
功能。
考慮拆分它pathStr.split("(\\\\[\\\\*]\\\\.|\\\\[\\\\*])").toList
然后迭代以獲取所有元素的一些方法並返回 JsLookupResult 但不確定如何。
只是為了澄清:
我的方法將接收 2 個參數, JsValue
和作為字符串的路徑def myFunc(json: JsValue, path: String)
每次我調用myFunc
它都會收到不同的路徑,我不確定只有在調用myFunc
之后它會是什么。
正如您在文檔中所見,您可以使用Reads
類型類來定義從 JSON 解碼類型的方式。
import play.api.libs.json._
val input = """{
"firstName": "Elon",
"lastName": "Musk",
"companies": [
{
"name": "Tesla",
"city": "San Francisco",
"offices": ["sf","ny"],
"management": {
"loscation": "New York",
"boardMembers": [
{
"name": "John",
"age": 45
},
{
"name": "Mike",
"age": 55
},
{
"name": "Rebecca",
"age": 35
}
]
}
},
{
"name": "SpaceX",
"city": "San Francisco",
"offices": ["la","ta"],
"management": {
"loscation": "San Mateo",
"boardMembers": [
{
"name": "Lisa",
"age": 45
},
{
"name": "Dan",
"age": 55
},
{
"name": "Henry",
"age": 35
}
]
}
}
]
}"""
val json = Json.parse(input)
// ---
case class BoardMember(name: String, age: Int)
implicit val br: Reads[BoardMember] = Json.reads
case class Company(boardMembers: Seq[BoardMember])
implicit val cr: Reads[Company] = Reads {
case obj @ JsObject(_) =>
(obj \ "management" \ "boardMembers").validate[Seq[BoardMember]].map {
Company(_)
}
case _ =>
JsError("error.obj.expected")
}
val reads = Reads[Seq[String]] {
case obj @ JsObject(_) =>
(obj \ "companies").validate[Seq[Company]].map {
_.flatMap(_.boardMembers.map(_.name))
}
case _ =>
JsError("error.obj.expected")
}
// ---
json.validate(reads)
// play.api.libs.json.JsResult[Seq[String]] = JsSuccess(Vector(John, Mike, Rebecca, Lisa, Dan, Henry),)
你可以做:
val jsPath = JsPath \ "companies" \\ "management" \ "boardMembers" \\ "name"
val result = jsPath(Json.parse(input))
println(result)
這將打印預期的輸出。 參見Scastie示例。
請注意\\
和\\\\
之間的區別:
要實現myFunc
您可以嘗試以下操作:
def findAllValuesAtPath(jsValue: JsValue, path: String): List[JsValue] = {
val jsPath = JsPath(path
.split("\\[\\*]\\.")
.flatMap(s => s.split("\\.")
.map(RecursiveSearch)
).toList)
println(jsPath.path)
jsPath(jsValue)
}
這是另一個scastie。
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