blocks|key|877443|text|这是一个基于提取器的解决方案，它将执行类类型转换：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|877444|class+CC[T]+{+def+unapply(a:Any):Option[T]+=+Some(a.asInstanceOf[T])+}

object+M+extends+CC[Map[String,+Any]]
object+L+extends+CC[List[Any]]
object+S+extends+CC[String]
object+D+extends+CC[Double]
object+B+extends+CC[Boolean]

val+jsonString+=
++++"""
++++++{
++++++++"languages":+[{
++++++++++++"name":+"English",
++++++++++++"is_active":+true,
++++++++++++"completeness":+2.5
++++++++},+{
++++++++++++"name":+"Latin",
++++++++++++"is_active":+false,
++++++++++++"completeness":+0.9
++++++++}]
++++++}
++++""".stripMargin

val+result+=+for+{
++++Some(M(map))+<-+List(JSON.parseFull(jsonString))
++++L(languages)+=+map("languages")
++++M(language)+<-+languages
++++S(name)+=+language("name")
++++B(active)+=+language("is_active")
++++D(completeness)+=+language("completeness")
}+yield+{
++++(name,+active,+completeness)
}

assert(+result+==+List(("English",true,2.5),+("Latin",false,0.9)))|code-block|syntax|javascript|877445|在for循环开始时，我人为地将结果包装在一个列表中，以便在结束时生成一个列表。然后，在for循环的其余部分中，我使用生成器(使用<-)和值定义(使用=)将使用unapply方法这一事实。|offset|length|style|CODE|877446|(较旧的答案被编辑掉了-如果你好奇，请检查编辑历史)|877447|entityMap^0|0|0|1S|2|22|1|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@$I|T|J|U|K|L]|$I|V|J|W|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|X|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|P|$]]

This is a solution based on extractors which will do the class cast:

<pre><code>class CC[T] { def unapply(a:Any):Option[T] = Some(a.asInstanceOf[T]) }

object M extends CC[Map[String, Any]]
object L extends CC[List[Any]]
object S extends CC[String]
object D extends CC[Double]
object B extends CC[Boolean]

val jsonString =
 """
 {
 "languages": [{
 "name": "English",
 "is_active": true,
 "completeness": 2.5
 }, {
 "name": "Latin",
 "is_active": false,
 "completeness": 0.9
 }]
 }
 """.stripMargin

val result = for {
 Some(M(map)) &lt;- List(JSON.parseFull(jsonString))
 L(languages) = map("languages")
 M(language) &lt;- languages
 S(name) = language("name")
 B(active) = language("is_active")
 D(completeness) = language("completeness")
} yield {
 (name, active, completeness)
}

assert( result == List(("English",true,2.5), ("Latin",false,0.9)))
</code></pre>

At the start of the for loop I artificially wrap the result in a list so that it yields a list at the end. Then in the rest of the for loop I use the fact that generators (using <code>&lt;-</code>) and value definitions (using <code>=</code>) will make use of the unapply methods.

(Older answer edited away - check edit history if you're curious)

blocks|key|877480|text|这是我进行模式匹配的方法：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|877481|val+result+=+JSON.parseFull(jsonStr)
result+match+{
++//+Matches+if+jsonStr+is+valid+JSON+and+represents+a+Map+of+Strings+to+Any
++case+Some(map:+Map[String,+Any])+=>+println(map)
++case+None+=>+println("Parsing+failed")
++case+other+=>+println("Unknown+data+structure:+"+%2B+other)
}|code-block|syntax|javascript|877482|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This is the way I do the pattern match:

<pre><code>val result = JSON.parseFull(jsonStr)
result match {
 // Matches if jsonStr is valid JSON and represents a Map of Strings to Any
 case Some(map: Map[String, Any]) =&gt; println(map)
 case None =&gt; println("Parsing failed")
 case other =&gt; println("Unknown data structure: " + other)
}
</code></pre>

blocks|key|877534|text|我喜欢@huynhjl的回答，它引导我走上了正确的道路。然而，它并不擅长处理错误条件。如果所需的节点不存在，则会出现强制转换异常。我稍微调整了一下，以便利用Option更好地处理这个问题。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|877535|class+CC[T]+{
++def+unapply(a:Option[Any]):Option[T]+=+if+(a.isEmpty)+{
++++None
++}+else+{
++++Some(a.get.asInstanceOf[T])
++}
}

object+M+extends+CC[Map[String,+Any]]
object+L+extends+CC[List[Any]]
object+S+extends+CC[String]
object+D+extends+CC[Double]
object+B+extends+CC[Boolean]

for+{
++M(map)+<-+List(JSON.parseFull(jsonString))
++L(languages)+=+map.get("languages")
++language+<-+languages
++M(lang)+=+Some(language)
++S(name)+=+lang.get("name")
++B(active)+=+lang.get("is_active")
++D(completeness)+=+lang.get("completeness")
}+yield+{
++(name,+active,+completeness)
}|code-block|syntax|javascript|877536|当然，这与其说是处理错误，不如说是避免错误。如果缺少任何json节点，这将产生一个空列表。您可以在执行操作之前使用match检查节点的存在...|877537|for+{
++M(map)+<-+Some(JSON.parseFull(jsonString))
}+yield+{
++map.get("languages")+match+{
++++case+L(languages)+=>+{
++++++for+{
++++++++language+<-+languages
++++++++M(lang)+=+Some(language)
++++++++S(name)+=+lang.get("name")
++++++++B(active)+=+lang.get("is_active")
++++++++D(completeness)+=+lang.get("completeness")
++++++}+yield+{
++++++++(name,+active,+completeness)
++++++}++++++++
++++}
++++case+None+=>+"bad+json"
++}
}|877538|entityMap^0|26|6|0|0|1L|5|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|P|$]]

I like @huynhjl's answer, it led me down the right path. However, it isn't great at handling error conditions. If the desired node does not exist, you get a cast exception. I've adapted this slightly to make use of <code>Option</code> to better handle this.

<pre><code>class CC[T] {
 def unapply(a:Option[Any]):Option[T] = if (a.isEmpty) {
 None
 } else {
 Some(a.get.asInstanceOf[T])
 }
}

object M extends CC[Map[String, Any]]
object L extends CC[List[Any]]
object S extends CC[String]
object D extends CC[Double]
object B extends CC[Boolean]

for {
 M(map) &lt;- List(JSON.parseFull(jsonString))
 L(languages) = map.get("languages")
 language &lt;- languages
 M(lang) = Some(language)
 S(name) = lang.get("name")
 B(active) = lang.get("is_active")
 D(completeness) = lang.get("completeness")
} yield {
 (name, active, completeness)
}
</code></pre>

Of course, this doesn't handle errors so much as avoid them. This will yield an empty list if any of the json nodes are missing. You can use a <code>match</code> to check for the presence of a node before acting...

<pre><code>for {
 M(map) &lt;- Some(JSON.parseFull(jsonString))
} yield {
 map.get("languages") match {
 case L(languages) =&gt; {
 for {
 language &lt;- languages
 M(lang) = Some(language)
 S(name) = lang.get("name")
 B(active) = lang.get("is_active")
 D(completeness) = lang.get("completeness")
 } yield {
 (name, active, completeness)
 } 
 }
 case None =&gt; "bad json"
 }
}
</code></pre>

blocks|key|877542|text|val+jsonString+=
++"""
++++%7C{
++++%7C+"languages":+[{
++++%7C+++++"name":+"English",
++++%7C+++++"is_active":+true,
++++%7C+++++"completeness":+2.5
++++%7C+},+{
++++%7C+++++"name":+"Latin",
++++%7C+++++"is_active":+false,
++++%7C+++++"completeness":+0.9
++++%7C+}]
++++%7C}
++""".stripMargin

val+result+=+JSON.parseFull(jsonString).map+{
++case+json:+Map[String,+List[Map[String,+Any]]]+=>
++++json("languages").map(l+=>+(l("name"),+l("is_active"),+l("completeness")))
}.get

println(result)

assert(+result+==+List(("English",+true,+2.5),+("Latin",+false,+0.9))+)|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|877543|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>val jsonString =
 """
 |{
 | "languages": [{
 | "name": "English",
 | "is_active": true,
 | "completeness": 2.5
 | }, {
 | "name": "Latin",
 | "is_active": false,
 | "completeness": 0.9
 | }]
 |}
 """.stripMargin

val result = JSON.parseFull(jsonString).map {
 case json: Map[String, List[Map[String, Any]]] =&gt;
 json("languages").map(l =&gt; (l("name"), l("is_active"), l("completeness")))
}.get

println(result)

assert( result == List(("English", true, 2.5), ("Latin", false, 0.9)) )
</code></pre>

blocks|key|877560|text|你可以这样做！非常容易解析JSON代码:P|type|unstyled|depth|inlineStyleRanges|entityRanges|data|877561|package+org.sqkb.service.common.bean

import+java.text.SimpleDateFormat

import+org.json4s
import+org.json4s.JValue
import+org.json4s.jackson.JsonMethods._
//import+org.sqkb.service.common.kit.{IsvCode}

import+scala.util.Try

/**
++*
++*/
case+class+Order(log:+String)+{

++implicit+lazy+val+formats+=+org.json4s.DefaultFormats

++lazy+val+json:+json4s.JValue+=+parse(log)

++lazy+val+create_time:+String+=+(json+\+"create_time").extractOrElse("1970-01-01+00:00:00")
++lazy+val+site_id:+String+=+(json+\+"site_id").extractOrElse("")
++lazy+val+alipay_total_price:+Double+=+(json+\+"alipay_total_price").extractOpt[String].filter(_.nonEmpty).getOrElse("0").toDouble
++lazy+val+gmv:+Double+=+alipay_total_price
++lazy+val+pub_share_pre_fee:+Double+=+(json+\+"pub_share_pre_fee").extractOpt[String].filter(_.nonEmpty).getOrElse("0").toDouble
++lazy+val+profit:+Double+=+pub_share_pre_fee

++lazy+val+trade_id:+String+=+(json+\+"trade_id").extractOrElse("")
++lazy+val+unid:+Long+=+Try((json+\+"unid").extractOpt[String].filter(_.nonEmpty).get.toLong).getOrElse(0L)
++lazy+val+cate_id1:+Int+=+(json+\+"cate_id").extractOrElse(0)
++lazy+val+cate_id2:+Int+=+(json+\+"subcate_id").extractOrElse(0)
++lazy+val+cate_id3:+Int+=+(json+\+"cate_id3").extractOrElse(0)
++lazy+val+cate_id4:+Int+=+(json+\+"cate_id4").extractOrElse(0)
++lazy+val+coupon_id:+Long+=+(json+\+"coupon_id").extractOrElse(0)

++lazy+val+platform:+Option[String]+=+Order.siteMap.get(site_id)


++def+time_fmt(fmt:+String+=+"yyyy-MM-dd+HH:mm:ss"):+String+=+{
++++val+dateFormat+=+new+SimpleDateFormat("yyyy-MM-dd+HH:mm:ss")
++++val+date+=+dateFormat.parse(this.create_time)
++++new+SimpleDateFormat(fmt).format(date)
++}

}|code-block|syntax|javascript|877562|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You can do like this! Very easy to parse JSON code :P

<pre><code>package org.sqkb.service.common.bean

import java.text.SimpleDateFormat

import org.json4s
import org.json4s.JValue
import org.json4s.jackson.JsonMethods._
//import org.sqkb.service.common.kit.{IsvCode}

import scala.util.Try

/**
 *
 */
case class Order(log: String) {

 implicit lazy val formats = org.json4s.DefaultFormats

 lazy val json: json4s.JValue = parse(log)

 lazy val create_time: String = (json \ "create_time").extractOrElse("1970-01-01 00:00:00")
 lazy val site_id: String = (json \ "site_id").extractOrElse("")
 lazy val alipay_total_price: Double = (json \ "alipay_total_price").extractOpt[String].filter(_.nonEmpty).getOrElse("0").toDouble
 lazy val gmv: Double = alipay_total_price
 lazy val pub_share_pre_fee: Double = (json \ "pub_share_pre_fee").extractOpt[String].filter(_.nonEmpty).getOrElse("0").toDouble
 lazy val profit: Double = pub_share_pre_fee

 lazy val trade_id: String = (json \ "trade_id").extractOrElse("")
 lazy val unid: Long = Try((json \ "unid").extractOpt[String].filter(_.nonEmpty).get.toLong).getOrElse(0L)
 lazy val cate_id1: Int = (json \ "cate_id").extractOrElse(0)
 lazy val cate_id2: Int = (json \ "subcate_id").extractOrElse(0)
 lazy val cate_id3: Int = (json \ "cate_id3").extractOrElse(0)
 lazy val cate_id4: Int = (json \ "cate_id4").extractOrElse(0)
 lazy val coupon_id: Long = (json \ "coupon_id").extractOrElse(0)

 lazy val platform: Option[String] = Order.siteMap.get(site_id)


 def time_fmt(fmt: String = "yyyy-MM-dd HH:mm:ss"): String = {
 val dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss")
 val date = dateFormat.parse(this.create_time)
 new SimpleDateFormat(fmt).format(date)
 }

}
</code></pre>

blocks|key|1092251|text|这就是我使用Scala解析器组合子库的方式：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1092252|import+scala.util.parsing.combinator._
class+ImprovedJsonParser+extends+JavaTokenParsers+{

++def+obj:+Parser[Map[String,+Any]]+=
++++"{"+~>+repsep(member,+",")+<~+"}"+%5E%5E+(Map()+%2B%2B+_)

++def+array:+Parser[List[Any]]+=
++++"["+~>+repsep(value,+",")+<~+"]"

++def+member:+Parser[(String,+Any)]+=
++++stringLiteral+~+":"+~+value+%5E%5E+{+case+name+~+":"+~+value+=>+(name,+value)+}

++def+value:+Parser[Any]+=+(
++++obj
++++++%7C+array
++++++%7C+stringLiteral
++++++%7C+floatingPointNumber+%5E%5E+(_.toDouble)
++++++%7C"true"
++++++%7C"false"
++++)

}
object+ImprovedJsonParserTest+extends+ImprovedJsonParser+{
++def+main(args:+Array[String])+{
++++val+jsonString+=
++++"""
++++++{
++++++++"languages":+[{
++++++++++++"name":+"English",
++++++++++++"is_active":+true,
++++++++++++"completeness":+2.5
++++++++},+{
++++++++++++"name":+"Latin",
++++++++++++"is_active":+false,
++++++++++++"completeness":+0.9
++++++++}]
++++++}
++++""".stripMargin


++++val+result+=+parseAll(value,+jsonString)
++++println(result)

++}
}|code-block|syntax|javascript|1092253|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This is the way I do the Scala Parser Combinator Library:

<pre><code>import scala.util.parsing.combinator._
class ImprovedJsonParser extends JavaTokenParsers {

 def obj: Parser[Map[String, Any]] =
 "{" ~&gt; repsep(member, ",") &lt;~ "}" ^^ (Map() ++ _)

 def array: Parser[List[Any]] =
 "[" ~&gt; repsep(value, ",") &lt;~ "]"

 def member: Parser[(String, Any)] =
 stringLiteral ~ ":" ~ value ^^ { case name ~ ":" ~ value =&gt; (name, value) }

 def value: Parser[Any] = (
 obj
 | array
 | stringLiteral
 | floatingPointNumber ^^ (_.toDouble)
 |"true"
 |"false"
 )

}
object ImprovedJsonParserTest extends ImprovedJsonParser {
 def main(args: Array[String]) {
 val jsonString =
 """
 {
 "languages": [{
 "name": "English",
 "is_active": true,
 "completeness": 2.5
 }, {
 "name": "Latin",
 "is_active": false,
 "completeness": 0.9
 }]
 }
 """.stripMargin


 val result = parseAll(value, jsonString)
 println(result)

 }
}
</code></pre>

blocks|key|1092290|text|scala.util.parsing.json.JSON已弃用。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1092291|这里是使用circe的另一种方法。参考文档：https://circe.github.io/circe/cursors.html|1092292|在build.sbt中添加依赖项，我使用的是scala+2.13.4，注意scala版本必须与库版本保持一致。|1092293|val+circeVersion+=+"0.14.0-M2"

libraryDependencies+%2B%2B=+Seq(
++"io.circe"++%25%25+"circe-core"+++++%25+circeVersion,
++"io.circe"++%25%25+"circe-generic"++%25+circeVersion,
++"io.circe"++%25%25+"circe-parser"+++%25+circeVersion
)|code-block|syntax|javascript|1092294|示例1：|1092295|case+class+Person(name:+String,+age:+Int)

object+Main+{
++def+main(args:+Array[String]):+Unit+=+{
++++val+input+=
++++++"""
++++++++%7C{
++++++++%7C++"kind":+"Listing",
++++++++%7C++"data":+[
++++++++%7C++++{
++++++++%7C++++++"name":+"Frodo",
++++++++%7C++++++"age":+51
++++++++%7C++++},
++++++++%7C++++{
++++++++%7C++++++"name":+"Bilbo",
++++++++%7C++++++"age":+60
++++++++%7C++++}
++++++++%7C++]
++++++++%7C}
++++++++%7C""".stripMargin

++++implicit+val+decoderPerson:+Decoder[Person]+=+deriveDecoder[Person]+//+decoder+required+to+parse+to+custom+object

++++val+parseResult:+Json+=+circe.parser.parse(input).getOrElse(Json.Null)
++++val+data:+ACursor+=+parseResult.hcursor.downField("data")+//+get+the+data+field
++++val+personList:+List[Person]+=+data.as[List[Person]].getOrElse(null)+//+parse+the+dataField+to+a+list+of+Person
++++for+{
++++++person+<-+personList
++++}+println(person.name+%2B+"+is+"+%2B+person.age)
++}
}|1092296|示例2，json在一个对象中有一个对象：|1092297|case+class+Person(name:+String,+age:+Int,+position:+Position)
case+class+Position(x:+Int,+y:+Int)

object+Main+{
++def+main(args:+Array[String]):+Unit+=+{
++++val+input+=
++++++"""
++++++++%7C{
++++++++%7C++"kind":+"Listing",
++++++++%7C++"data":+[
++++++++%7C++++{
++++++++%7C++++++"name":+"Frodo",
++++++++%7C++++++"age":+51,
++++++++%7C++++++"position":+{
++++++++%7C++++++++"x":+10,
++++++++%7C++++++++"y":+20
++++++++%7C++++++}
++++++++%7C++++},
++++++++%7C++++{
++++++++%7C++++++"name":+"Bilbo",
++++++++%7C++++++"age":+60,
++++++++%7C++++++"position":+{
++++++++%7C++++++++"x":+75,
++++++++%7C++++++++"y":+85
++++++++%7C++++++}
++++++++%7C++++}
++++++++%7C++]
++++++++%7C}
++++++++%7C""".stripMargin

++++implicit+val+decoderPosition:+Decoder[Position]+=+deriveDecoder[Position]+//+must+be+defined+before+the+Person+decoder
++++implicit+val+decoderPerson:+Decoder[Person]+=+deriveDecoder[Person]

++++val+parseResult+=+circe.parser.parse(input).getOrElse(Json.Null)
++++val+data+=+parseResult.hcursor.downField("data")
++++val+personList+=+data.as[List[Person]].getOrElse(null)
++++for+{
++++++person+<-+personList
++++}+println(person.name+%2B+"+is+"+%2B+person.age+%2B+"+at+"+%2B+person.position)
++}
}|1092298|entityMap|0|LINK|mutability|MUTABLE|url|https://circe.github.io/circe/cursors.html^0|0|S|0|5|5|M|16|0|0|1|9|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|14|8|@$9|15|A|16|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|17|8|@$9|18|A|19|B|C]]|D|@$9|1A|A|1B|1|1C]]|E|$]]|$1|H|3|I|5|6|7|1D|8|@$9|1E|A|1F|B|C]]|D|@]|E|$]]|$1|J|3|K|5|L|7|1G|8|@]|D|@]|E|$M|N]]|$1|O|3|P|5|6|7|1H|8|@]|D|@]|E|$]]|$1|Q|3|R|5|L|7|1I|8|@]|D|@]|E|$M|N]]|$1|S|3|T|5|6|7|1J|8|@]|D|@]|E|$]]|$1|U|3|V|5|L|7|1K|8|@]|D|@]|E|$M|N]]|$1|W|3|-4|5|6|7|1L|8|@]|D|@]|E|$]]]|X|$Y|$5|Z|10|11|E|$12|13]]]]

<code>scala.util.parsing.json.JSON</code> is deprecated.
Here is another approach with <code>circe</code>. FYI documentation: <a href="https://circe.github.io/circe/cursors.html" rel="nofollow noreferrer">https://circe.github.io/circe/cursors.html</a>
Add the dependency in <code>build.sbt</code>, I used scala 2.13.4, note the scala version must align with the library version.
<pre><code>val circeVersion = &quot;0.14.0-M2&quot;

libraryDependencies ++= Seq(
 &quot;io.circe&quot; %% &quot;circe-core&quot; % circeVersion,
 &quot;io.circe&quot; %% &quot;circe-generic&quot; % circeVersion,
 &quot;io.circe&quot; %% &quot;circe-parser&quot; % circeVersion
)
</code></pre>
Example 1:
<pre><code>case class Person(name: String, age: Int)

object Main {
 def main(args: Array[String]): Unit = {
 val input =
 &quot;&quot;&quot;
 |{
 | &quot;kind&quot;: &quot;Listing&quot;,
 | &quot;data&quot;: [
 | {
 | &quot;name&quot;: &quot;Frodo&quot;,
 | &quot;age&quot;: 51
 | },
 | {
 | &quot;name&quot;: &quot;Bilbo&quot;,
 | &quot;age&quot;: 60
 | }
 | ]
 |}
 |&quot;&quot;&quot;.stripMargin

 implicit val decoderPerson: Decoder[Person] = deriveDecoder[Person] // decoder required to parse to custom object

 val parseResult: Json = circe.parser.parse(input).getOrElse(Json.Null)
 val data: ACursor = parseResult.hcursor.downField(&quot;data&quot;) // get the data field
 val personList: List[Person] = data.as[List[Person]].getOrElse(null) // parse the dataField to a list of Person
 for {
 person &lt;- personList
 } println(person.name + &quot; is &quot; + person.age)
 }
}
</code></pre>
Example 2, json has an object within an object:
<pre><code>case class Person(name: String, age: Int, position: Position)
case class Position(x: Int, y: Int)

object Main {
 def main(args: Array[String]): Unit = {
 val input =
 &quot;&quot;&quot;
 |{
 | &quot;kind&quot;: &quot;Listing&quot;,
 | &quot;data&quot;: [
 | {
 | &quot;name&quot;: &quot;Frodo&quot;,
 | &quot;age&quot;: 51,
 | &quot;position&quot;: {
 | &quot;x&quot;: 10,
 | &quot;y&quot;: 20
 | }
 | },
 | {
 | &quot;name&quot;: &quot;Bilbo&quot;,
 | &quot;age&quot;: 60,
 | &quot;position&quot;: {
 | &quot;x&quot;: 75,
 | &quot;y&quot;: 85
 | }
 | }
 | ]
 |}
 |&quot;&quot;&quot;.stripMargin

 implicit val decoderPosition: Decoder[Position] = deriveDecoder[Position] // must be defined before the Person decoder
 implicit val decoderPerson: Decoder[Person] = deriveDecoder[Person]

 val parseResult = circe.parser.parse(input).getOrElse(Json.Null)
 val data = parseResult.hcursor.downField(&quot;data&quot;)
 val personList = data.as[List[Person]].getOrElse(null)
 for {
 person &lt;- personList
 } println(person.name + &quot; is &quot; + person.age + &quot; at &quot; + person.position)
 }
}
</code></pre>

I am using the build in JSON class in Scala 2.8 to parse JSON code. I don't want to use the Liftweb one or any other due to minimizing dependencies.

The way I am doing it seems too imperative, is there a better way to do it?

<pre><code>import scala.util.parsing.json._
...
val json:Option[Any] = JSON.parseFull(jsonString)
val map:Map[String,Any] = json.get.asInstanceOf[Map[String, Any]]
val languages:List[Any] = map.get("languages").get.asInstanceOf[List[Any]]
languages.foreach( langMap =&gt; {
val language:Map[String,Any] = langMap.asInstanceOf[Map[String,Any]]
val name:String = language.get("name").get.asInstanceOf[String]
val isActive:Boolean = language.get("is_active").get.asInstanceOf[Boolean]
val completeness:Double = language.get("completeness").get.asInstanceOf[Double]
}
</code></pre>

How to parse JSON in Scala using standard Scala classes?

JSON

我正在使用Scala2.8中的build in JSON类来解析JSON代码。我不想使用Liftweb one或任何其他的，因为最小化了依赖性。我这样做似乎太刻不容缓了，有没有更好的方法呢？import scala.util.parsing.json._...val json:Option[Any] = JSON.pa...

问如何在Scala中使用标准的Scala类解析JSON？
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