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POScala Parse recursive JSON
 

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  1. POScala Parse recursive JSON
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    <p>I'm trying to parse JSON in scala and I'm not very successfull. Here's my JSON structure:</p> <pre><code>{ "data" : "test", "field" : "test", "listObj" : [{ "data" : "testInner1", "field" : "testInner1" } , { "data" : "testInner2", "field" : "testInner2" }], "obj" : { "data" : "testInner1", "field" : "testInner1" } } </code></pre> <p>I'm using lift to parse. Here's my code:</p> <pre><code>import net.liftweb.json._ implicit val formats = DefaultFormats case class MyJson(data: String, field: String, obj: MyJson, listObj: List[MyJson]) val json = parse(""" { "data" : "test", "field" : "test", "listObj" : [{ "data" : "testInner1", "field" : "testInner1" } , { "data" : "testInner2", "field" : "testInner2" }], "obj" : { "data" : "testInner1", "field" : "testInner1" } }""") println(json.extract[Query]) </code></pre> <p>I've god the following exception:</p> <pre><code>Caused by: net.liftweb.json.MappingException: No usable value for operation Did not find value which can be converted into java.lang.String at net.liftweb.json.Meta$.fail(Meta.scala:191) at net.liftweb.json.Extraction$.mkValue$1(Extraction.scala:357) at net.liftweb.json.Extraction$.net$liftweb$json$Extraction$$build$1(Extraction.scala:317) at net.liftweb.json.Extraction$$anonfun$13.apply(Extraction.scala:253) at net.liftweb.json.Extraction$$anonfun$13.apply(Extraction.scala:253) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244) at scala.collection.immutable.List.foreach(List.scala:318) at scala.collection.TraversableLike$class.map(TraversableLike.scala:244) at scala.collection.AbstractTraversable.map(Traversable.scala:105) at net.liftweb.json.Extraction$.instantiate$1(Extraction.scala:253) at net.liftweb.json.Extraction$.newInstance$1(Extraction.scala:286) at net.liftweb.json.Extraction$.net$liftweb$json$Extraction$$build$1(Extraction.scala:315) at net.liftweb.json.Extraction$.mkValue$1(Extraction.scala:351) ... 34 more Caused by: net.liftweb.json.MappingException: Did not find value which can be converted into java.lang.String at net.liftweb.json.Meta$.fail(Meta.scala:191) at net.liftweb.json.Extraction$.convert(Extraction.scala:403) at net.liftweb.json.Extraction$.net$liftweb$json$Extraction$$build$1(Extraction.scala:314) at net.liftweb.json.Extraction$.mkValue$1(Extraction.scala:351) ... 46 more </code></pre> <p>I've tried using json4s but I could manage to make it parse into case classes. When I remove the obj and objList from my JSON, it works well.</p> <p>Anyone can point me out some way to parse this kind of structure to read it in Scala?</p>
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    1. PO
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    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USAugusto
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
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      1. POScala Parse recursive JSON
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      1. VTUpMod
    1. CODo you mean "nested", rather than "recursive"? Recursive objects usually contain a nested pointer to themselves.
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      1. USnafg
    2. COnope. recursive. the json object contains itself in it.
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      1. USAugusto
    3. COIt contains *itself* (if so can you help me see how?), or it contains an object of the same *type*?
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      1. USnafg
 

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