Scala 使用Play JSON查询并查找JSON元素值的路径
我将Play框架与Scala一起使用。对于上游服务器返回的JSON,我有以下结构。这只是一种表述Scala 使用Play JSON查询并查找JSON元素值的路径,scala,playframework,jsonpath,Scala,Playframework,Jsonpath,我将Play框架与Scala一起使用。对于上游服务器返回的JSON,我有以下结构。这只是一种表述 { "key": "some-key", "suspendData": { "d": [ [ "arbitrary-objects/strings" ], [ "random-value", [ "arbitrary-objects/strings" ],
{
"key": "some-key",
"suspendData": {
"d": [
[
"arbitrary-objects/strings"
],
[
"random-value",
[
"arbitrary-objects/strings"
],
[
[
"value1",
"important-item",
[
"important-key-1"
],
"arbitrary-values/objects"
],
[
"value2",
"important-item-2",
[
"important-key-2"
]
]
]
]
]
}
}
我所掌握的唯一事实是,数据将位于$.suspendData.d[1]
中的某个位置。我知道我正在搜索的值是important-key-1
。该值可以嵌套得更深,也可以位于`d[1]中的其他索引上。我如何处理发现
$.suspendData.d[1]
,然后循环查找是否存在此类属性。
再一次,我找不到通过JsPath实现这一点的正确方法。我知道JsonPath等价物,但无法通过现有的Play JSON支持找到正确的方法。您可以使用
JsValue
上定义的\
方法,导航到JSON中您想要的位置
要获取您想要的内容,请执行以下操作:((json\'suspendData')\'d”)(1)
以下是相同的REPL输出
scala> val json = Json.parse(str)
json: JsValue = {"key":"some-key","suspendData":{"d":[["arbitrary-objects/strings"],["random-value",["arbitrary-objects/strings"],[["value1","important-item",["important-key-1"],"arbitrary-values/objects"],["value2","important-item-2",["important-key-2"]]]]]}}
scala> ((json \ "suspendData") \ "d")(1)
res32: JsLookupResult = JsDefined(
["random-value",["arbitrary-objects/strings"],[["value1","important-item",["important-key-1"],"arbitrary-values/objects"],["value2","important-item-2",["important-key-2"]]]]
)
scala> val json = Json.parse(str)
json: JsValue = {"key":"some-key","suspendData":{"d":[["arbitrary-objects/strings"],["random-value",["arbitrary-objects/strings"],[["value1","important-item",["important-key-1"],"arbitrary-values/objects"],["value2","important-item-2",["important-key-2"]]]]]}}
scala> (json \ "suspendData")
res34: JsLookupResult = JsDefined(
{"d":[["arbitrary-objects/strings"],["random-value",["arbitrary-objects/strings"],[["value1","important-item",["important-key-1"],"arbitrary-values/objects"],["value2","important-item-2",["important-key-2"]]]]]}
)
scala> (json \ "suspendData") \ "d"
res35: JsLookupResult = JsDefined(
[["arbitrary-objects/strings"],["random-value",["arbitrary-objects/strings"],[["value1","important-item",["important-key-1"],"arbitrary-values/objects"],["value2","important-item-2",["important-key-2"]]]]]
)
scala> ((json \ "suspendData") \ "d")(0)
res36: JsLookupResult = JsDefined(["arbitrary-objects/strings"])
scala> ((json \ "suspendData") \ "d")(1)
res37: JsLookupResult = JsDefined(
["random-value",["arbitrary-objects/strings"],[["value1","important-item",["important-key-1"],"arbitrary-values/objects"],["value2","important-item-2",["important-key-2"]]]]
)
简单递归,可能不太有效,但有效:
def findPath(key: String, path: JsPath, xs: JsValue): Option[JsPath] = {
xs match {
case o:JsObject =>
var res: Option[JsPath] = None
val it = o.fields.iterator
while (res.isEmpty && it.hasNext) {
val e = it.next()
res = findPath(key, path \ (e._1), e._2)
}
res
case JsString(x) if x==key =>
Some(path)
case JsArray(x) =>
var res: Option[JsPath] = None
val it = x.zipWithIndex.iterator
while (res.isEmpty && it.hasNext) {
val e = it.next()
res = findPath(key, path(e._2), e._1)
}
res
case _ => None
}
}
findPath("important-key-1", __, j)
findPath("important-key-2", __, j)
findPath("important-key-3", __, j)
findPath("some-key", __, j)
scala> res62: Option[play.api.libs.json.JsPath] = Some(/suspendData/d(1)(2)(0)(2)(0))
scala> res63: Option[play.api.libs.json.JsPath] = Some(/suspendData/d(1)(2)(1)(2)(0))
scala> res64: Option[play.api.libs.json.JsPath] = None
scala> res65: Option[play.api.libs.json.JsPath] = Some(/key)
+1这部分回答了与JsPath相关的问题,但我的主要问题是确定应该使用哪条路径。所以,我需要一个反向查找。找到一个特定值并确定可用于达到该值的路径。以有效的方式。不确定是否有效,但至少它帮助我前进!