1、转json
import org.json4s.JsonDSL._import org.json4s.jackson.JsonMethods._import org.json4s.jackson.Serialization._import org.json4s.jackson.Serializationcase class WOE(col: String, woe: Map[String, String])implicit val formats = Serialization.formats(NoTypeHints)val testMap = Map[String, String]()testMap += ("1" -> "1.1")val a = WOE("1", immutable.Map(testMap.toList:_*))println(write(a)) 输入{"col":"1","woe":{"1":"1.1"}}
2、解析json
implicit val formats = Serialization.formats(NoTypeHints)val js ="""{"col":"1","woe":{"1":"1.1"}}"""val ab = parse(js).extract[WOE]println(write(ab)) 如果是List也能够
implicit val formats = Serialization.formats(NoTypeHints) val b = new ListBuffer[WOE] val testMap = Map[String, String]() testMap += ("1" -> "1.1") b += WOE("1", immutable.Map(testMap.toList:_*)) b += WOE("3", immutable.Map(testMap.toList:_*)) println(write(b))val js = """ [{"col":"1","woe":{"1":"1.1"}},{"col":"3","woe":{"1":"1.1"}}] """ val ab = parse(js).extract[List[WOE]] println(ab.toString) 1、scala自带的Json解析
scala 2.10（以上，其余版本不分明）自带Json解析，scala.util.parsing.json.JSON
object转json
val testMap = Map[String, String]() testMap += ("1" -> "2.034") testMap += ("2" -> "2.0134") println(scala.util.parsing.json.JSONObject(scala.collection.immutable.Map(testMap.toList: _*))) 但如同只能解决map，且map要转成immutable
2、fastjson
解析json
import com.alibaba.fastjson.JSONobject JsonDemo { def main(args: Array[String]) { val text = "{"name":"name1", "age":55}" val json = JSON.parseObject(text) println(json.get("name")) println(json.get("age")) }} 再例如
import com.alibaba.fastjson.JSONobject Json { def main(args: Array[String]): Unit = { val str2 = "{"et":"kanqiu_client_join","vtm":1435898329434,"body":{"client":"866963024862254","client_type":"android","room":"NBA_HOME","gid":"","type":"","roomid":""},"time":1435898329}" val json=JSON.parseObject(str2) //获取成员 val fet=json.get("et") //返回字符串成员 val etString=json.getString("et") //返回整形成员 val vtm=json.getInteger("vtm") println(vtm) //返回多级成员 val client=json.getJSONObject("body").get("client") println(client) 在spark-steaming中,应用fast-json更加稳固,json-lib经常出现莫名问题,而且fastjson的解析速度更快.
object转json，首先必须要显式的定义参数，否则会报错
ambiguous reference to overloaded definition
1
例如：
val testMap = Map[String, String]()testMap += ("1" -> "2.034")testMap += ("2" -> "2.0134")val a = JSON.toJSONString(testMap, true)println(a) 不会报错，然而输入后果是奇怪的
{ "empty":false, "sizeMapDefined":false, "traversableAgain":true} 3、json4s
object转json
val testMap = Map[String, String]()testMap += ("1" -> "2.034")testMap += ("2" -> "2.0134")val jj = compact(render(testMap))println(jj) 输入
[{"2":"2.0134"},{"1":"2.034"}] 如果都是String，简单的Map构造也能够解析
val testMap = Map[String, Map[String, String]]()val subMap = Map[String, String]()subMap += ("1" -> "1.1")testMap += ("1" -> subMap)println(write(testMap)) 输入{"1":{"1":"1.1"}}
但这样的模式不利于解析
再例如
implicit val formats = Serialization.formats(NoTypeHints)val m = Map( "name" -> "john doe", "age" -> 18, "hasChild" -> true, "childs" -> List( Map("name" -> "dorothy", "age" -> 5, "hasChild" -> false), Map("name" -> "bill", "age" -> 8, "hasChild" -> false))) val mm = Map( "1" -> Map ("1"->"1.2") )println(write(a)) TEST
package com.dfssi.dataplatform.analysis.exhaust.alarmimport java.sql.Timestampimport java.utilimport com.alibaba.fastjson.serializer.SerializerFeatureimport org.apache.spark.Loggingimport org.json4s.NoTypeHints//将要解析得数据case class NeedEntity(val vin: String, val downoutput: Double, val collectTime: Long, val lon: Double, val lat: Double, val failureList: java.util.List[Integer] = new util.ArrayList[Integer]() ) extends Serializable//治理状态//这是事件治理得 依照每个事件来解决class OverLimitEvent(var vin: String, var startTime: Long, var startLon: Double, var startLat: Double, var eventType:String="overlimit", var endTime: Long = 0, var endLon: Double = 0.0, var endLat: Double = 0.0, var minValue: Double = 0.0, var maxValue: Double = 0.0 ) extends Serializable with Logging{ def getInsertMap(): Map[String, Any] = { Map( "vin" -> vin, "startTime" -> new Timestamp(startTime), "startLon" -> startLon, "startLat" -> startLat ) } def getUpdateMap(): Map[String, Any] = { Map( "vin" -> vin, "startTime" -> new Timestamp(startTime), "endTime" -> new Timestamp(startTime), "endLon" -> startLon, "endLat" -> startLat, "maxValue" -> maxValue, "minValue" -> minValue ) } def updateByEntity(entity: NeedEntity) = { this.endTime = entity.collectTime this.endLat = entity.lat this.endLon = entity.lon if (this.maxValue != null && this.maxValue < entity.downoutput) { this.maxValue = entity.downoutput } if (this.minValue != null && this.minValue > entity.downoutput) { this.minValue = entity.downoutput } } override def toString(): String ={ import org.json4s.jackson.Serialization._ import org.json4s.jackson.Serialization implicit val formats = Serialization.formats(NoTypeHints) write(this) }}object OverLimitEvent { val ID_FIELD = Array("vin", "startTime") def apply( vin: String, startTime: Long, startLon: Double, startLat: Double, endTime: Long, endLon: Double, endLat: Double, minValue: Double, maxValue: Double ): OverLimitEvent = { val event = new OverLimitEvent(vin, startTime, startLon, startLat) event.endTime = endTime event.endLat = endLat event.endLon = endLon event.maxValue = maxValue event.minValue = minValue event } def buildByEntity(entity: NeedEntity): OverLimitEvent = { new OverLimitEvent(entity.vin, entity.collectTime, entity.lon, entity.lat) } def buildByJson(json: String): OverLimitEvent = { com.alibaba.fastjson.JSON.parseObject(json, classOf[OverLimitEvent]) } override def toString(): String ={ import org.json4s.jackson.Serialization._ import org.json4s.jackson.Serialization implicit val formats = Serialization.formats(NoTypeHints) write(this) }}case class ExhaustAlarmStatus(val vin: String, var overLimitEvent: OverLimitEvent=null,var faultEvent:Map[String,OverLimitEvent]=null, var lastTime: Long) { override def toString(): String ={ import org.json4s.jackson.Serialization._ import org.json4s.jackson.Serialization implicit val formats = Serialization.formats(NoTypeHints) write(this) }}object ExhaustAlarmStatus { def buildByJson(json: String): ExhaustAlarmStatus = { if(json!=null){ com.alibaba.fastjson.JSON.parseObject(json, classOf[ExhaustAlarmStatus]) }else{ null } } def toJSON(state: ExhaustAlarmStatus): String = com.alibaba.fastjson.JSON.toJSONString(state, SerializerFeature.PrettyFormat) def main(args: Array[String]): Unit = { val json = "{"vin":"222", "OverLimitEvent":{ "vin":"222", "startTime":123456789, "startLon":1.0, "startLat":1.0, "endTime":123456789, "endLon":1.0, "endLat":1.0, "minValue":1.0, "maxValue":1.0 },"lastTime":1556441242000}"; val state = com.alibaba.fastjson.JSON.parseObject(json, classOf[ExhaustAlarmStatus]) println(state.overLimitEvent) import org.json4s.JsonDSL._ import org.json4s.jackson.JsonMethods._ import org.json4s.jackson.Serialization._ import org.json4s.jackson.Serialization implicit val formats = Serialization.formats(NoTypeHints) val jsonstr = write(state) println(jsonstr) }}