Convert JValue to Map[String, Any]

[lovesh]

There should be method to convert the parsed json string to a Map, like most languages have. Right now i have to make a case class and then convert it to a map.

[casualjim]

you can extract a Map[String, Any].

[lovesh]

extracting with a Map[String, Any] gives an exception.
eg.
val json = parse(""" { "name": "joe", "children": [ { "name": "Mary", "age": 5 }, { "name": "Mazy", "age": 3 } ] } """)

Now
json.extract[Map[String, Any]] gives exception

org.json4s.package$MappingException: No information known about type at org.json4s.Extraction$ClassInstanceBuilder.org$json4s$Extraction$ClassInstanceBuilder$$instantiate(Extraction.scala:465) at org.json4s.Extraction$ClassInstanceBuilder$$anonfun$result$6.apply(Extraction.scala:491) at org.json4s.Extraction$ClassInstanceBuilder$$anonfun$result$6.apply(Extraction.scala:488) at org.json4s.Extraction$.org$json4s$Extraction$$customOrElse(Extraction.scala:500) at org.json4s.Extraction$ClassInstanceBuilder.result(Extraction.scala:488) at org.json4s.Extraction$.extract(Extraction.scala:332) at org.json4s.Extraction$$anonfun$extract$5.apply(Extraction.scala:316) at org.json4s.Extraction$$anonfun$extract$5.apply(Extraction.scala:316) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.immutable.List.foreach(List.scala:318) at scala.collection.TraversableLike$class.map(TraversableLike.scala:244) at scala.collection.AbstractTraversable.map(Traversable.scala:105) at org.json4s.Extraction$.extract(Extraction.scala:316) at org.json4s.Extraction$.extract(Extraction.scala:42) at org.json4s.ExtractableJsonAstNode.extract(ExtractableJsonAstNode.scala:21) at .<init>(<console>:18) at .<clinit>(<console>) at .<init>(<console>:7) at .<clinit>(<console>) at $print(<console>) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at scala.tools.nsc.interpreter.IMain$ReadEvalPrint.call(IMain.scala:734) at scala.tools.nsc.interpreter.IMain$Request.loadAndRun(IMain.scala:983) at scala.tools.nsc.interpreter.IMain.loadAndRunReq$1(IMain.scala:573) at scala.tools.nsc.interpreter.IMain.interpret(IMain.scala:604) at scala.tools.nsc.interpreter.IMain.interpret(IMain.scala:568) at scala.tools.nsc.interpreter.ILoop.reallyInterpret$1(ILoop.scala:756) at scala.tools.nsc.interpreter.ILoop.interpretStartingWith(ILoop.scala:801) at scala.tools.nsc.interpreter.ILoop.command(ILoop.scala:713) at scala.tools.nsc.interpreter.ILoop.processLine$1(ILoop.scala:577) at scala.tools.nsc.interpreter.ILoop.innerLoop$1(ILoop.scala:584) at scala.tools.nsc.interpreter.ILoop.loop(ILoop.scala:587) at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply$mcZ$sp(ILoop.scala:878) at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply(ILoop.scala:833) at scala.tools.nsc.interpreter.ILoop$$anonfun$process$1.apply(ILoop.scala:833) at scala.tools.nsc.util.ScalaClassLoader$.savingContextLoader(ScalaClassLoader.scala:135) at scala.tools.nsc.interpreter.ILoop.process(ILoop.scala:833) at scala.tools.nsc.interpreter.ILoop.main(ILoop.scala:900) at xsbt.ConsoleInterface.run(ConsoleInterface.scala:69) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at sbt.compiler.AnalyzingCompiler.call(AnalyzingCompiler.scala:102) at sbt.compiler.AnalyzingCompiler.console(AnalyzingCompiler.scala:77) at sbt.Console.sbt$Console$$console0$1(Console.scala:23) at sbt.Console$$anonfun$apply$2$$anonfun$apply$1.apply$mcV$sp(Console.scala:24) at sbt.Console$$anonfun$apply$2$$anonfun$apply$1.apply(Console.scala:24) at sbt.Console$$anonfun$apply$2$$anonfun$apply$1.apply(Console.scala:24) at sbt.Logger$$anon$4.apply(Logger.scala:90) at sbt.TrapExit$App.run(TrapExit.scala:244) at java.lang.Thread.run(Thread.java:745)

[lovesh]

Is there some other way of converting JValue to Map[String, Any]?

[fedeoasi]

I believe I fixed this in #126

[jarandaf]

On 3.2.11 release seems to be working fine.

[ziziermao]

Hey, I still have this problem when trying to do parse(entry).extract[Map[String, Any]]. Any suggestions?

[ziziermao]

Hey guys,
I am trying having this problem when doing
parse(entry).extract[Map[String, Any]]
I got:
org.json4s.package$MappingException: No information known about type

[fedeoasi]

@ziziermao: Extracting a Map[String, Any] works fine for me on the latest version (3.4.0). Could you share the json fragment that you're trying to extract and the version of json4s that you are using?