Scala中json格式、字符串、map相互转换
像map一样的json直接存值:
import org.json.JSONObject
def main(args: Array[String]): Unit = { val jsonObj :JSONObject= new JSONObject() |
json对象转换为json字符串:
import org.json4s.{Formats,NoTypeHints} import org.json4s.jackson.Serialization import org.json4s.jackson.Serialization.write case class userLableLike(id:String,pos:Float,neg:Float,seg:Double) def userLable2Str(data:userLableLike): String ={ // 需要添加隐式转换 implicit val formats:AnyRef with Formats = Serialization.formats(NoTypeHints) // 由scala对象转换为Json字符串 val dstr = write(data) dstr } val v1 = userLableLike("1",100,100,0.5) println(userLable2Str(v1)) // "{id: 1, pos: 100, neg: 100, seg: 0.5}"
json字符串转换成map:
import scala.util.parsing.json.JSON // 把json格式的字符串转换成map格式,(id:String,pos:Float,neg:Float,seg:Double) def str2map(vstr:String): collection.immutable.Map[String, Any] ={ val vSome = JSON.parseFull(vstr) // println(vSome,manOf(vSome)) //(Map(id -> 1, pos -> 100.0, neg -> 100.0, seg -> 0.5),Any) // 转换类型 var vmap = vSome match { case Some(map:collection.immutable.Map[String, Any]) => map } // println(vmap("id"),manOf(vmap)) //(1,scala.collection.immutable.Map[java.lang.String, Any]) vmap } //注意用可变集合collection.mutable.Map[String, Any] ,行不通 //查看数据类型方法-manOf(data) def manOf[T:Manifest](t:T):Manifest[T]=manifest[T]
<dependency> |