scala 自带json_Scala JSON

scala 自带json模块

import scala.util.parsing.json

不用第三方包， 解析和拼接都不好控制

# map -> scala.util.parsing.json.JSONObject

scala.util.parsing.json.JSONObject(map).toString()

# list -> scala.util.parsing.json.JSONArray

scala.util.parsing.json.JSONArray(list).toString()

# json -> map

import scala.util.parsing.json.JSON

import scala.util.parsing.json.JSONObject

val colors:Map[String,Object] = Map("red" -> "123456", "azure" -> "789789")

val json = JSONObject(colors)

println(json)

val jsonMap = JSON.parseFull(json.toString).get.asInstanceOf[Map[String,Object]]

println(jsonMap)

/* ---------------------------------------- */

val jsonStr = """{"username":"Ricky", "age":"21"}"""

val jsonValue = JSON.parseFull(jsonStr)

val jsonObj = jsonValue match {

case Some(map:Map[String, Any]) => map.asInstanceOf[Map[String,String]]

case _ => println("ERROR jsonStr")

}

val username = jsonObj.get("username")

import scala.util.parsing.json.JSON

val jsonStr = """{"username":"Ricky", "attribute":{"age":21, "weight": 60}}"""

val jsonValue = JSON.parseFull(jsonStr)

val jsonObj = jsonValue match {

case Some(map:Map[String, Any]) => map

case other => println("Error jsonStr")

}

// 将attribute转换成Map

val attrObj = jsonObj.get("attribute").get.asInstanceOf[Map[String, String]]

val age = attrObj.get("age")

json4s

org.json4s

json4s-jackson_${scala.version}

{latestVersion}

官网地址： https://github.com/json4s/json4s

生成和解析json的过程都有些麻烦， 不能直接生成一个map或list

JObject解析, 但json和xml格式可以互转

# json -> List

import org.json4s._

import org.json4s.jackson.JsonMethods._

var temp = new ListBuffer[(String, Long, Int)]

val dataLog = parse(x.toString)

for {JObject(child)

JField("url", JString(url))

JField("time", JInt(time))

JField("origin", JInt(origin))

if origin.toDouble.toInt >= 1

}

temp += Tuple4(url,

time.toDouble.toLong,

origin.toString.toDouble.toInt)

样例类解析

scala> import org.json4s._

scala> import org.json4s.jackson.JsonMethods._

scala> implicit val formats = DefaultFormats // Brings in default date formats etc.

scala> case class Child(name: String, age: Int, birthdate: Option[java.util.Date])

scala> case class Address(street: String, city: String)

scala> case class Person(name: String, address: Address, children: List[Child])

scala> val json = parse("""

{ "name": "joe",

"address": {

"street": "Bulevard",

"city": "Helsinki"

},

"children": [

{

"name": "Mary",

"age": 5,

"birthdate": "2004-09-04T18:06:22Z"

},

{

"name": "Mazy",

"age": 3

}

]

}

""")

scala> json.extract[Person]

res0: Person = Person(joe,Address(Bulevard,Helsinki),List(Child(Mary,5,Some(Sat Sep 04 18:06:22 EEST 2004)), Child(Mazy,3,None)))

scala> val addressJson = json \ "address" // Extract address object

scala> addressJson.extract[Address]

res1: Address = Address(Bulevard,Helsinki)

scala> (json \ "children").extract[List[Child]] // Extract list of objects

res2: List[Child] = List(Child(Mary,5,Some(Sat Sep 04 23:36:22 IST 2004)), Child(Mazy,3,None))

json拼接

# map -> json

object JsonExample extends App {

import org.json4s._

import org.json4s.JsonDSL._

import org.json4s.jackson.JsonMethods._

case class Winner(id: Long, numbers: List[Int])

case class Lotto(id: Long, winningNumbers: List[Int], winners: List[Winner], drawDate: Option[java.util.Date])

val winners = List(Winner(23, List(2, 45, 34, 23, 3, 5)), Winner(54, List(52, 3, 12, 11, 18, 22)))

val lotto = Lotto(5, List(2, 45, 34, 23, 7, 5, 3), winners, None)

val json =

("lotto" ->

("lotto-id" -> lotto.id) ~

("winning-numbers" -> lotto.winningNumbers) ~

("draw-date" -> lotto.drawDate.map(_.toString)) ~

("winners" ->

lotto.winners.map { w =>

(("winner-id" -> w.id) ~

("numbers" -> w.numbers))}))

println(compact(render(json)))

}

scala> JsonExample

{"lotto":{"lotto-id":5,"winning-numbers":[2,45,34,23,7,5,3],"winners":

[{"winner-id":23,"numbers":[2,45,34,23,3,5]},{"winner-id":54,"numbers":[52,3,12,11,18,22]}]}}

gson

json case class

import com.google.gson.Gson

case class Student( name:String , no: String )

val gson = new Gson

val student = Student("张三", "100")

val str = gson.toJson(student, classOf[Student])

println(str)

val student2 = gson.fromJson(str, classOf[Student])

println(student2)

json javaMap

// 注意这里只能是java的HashMap 或者其子类LinkedHashMap, TreeMap

// 经实验 scala的Map 以及 java.util.Map 都会有问题的

val map = new java.util.HashMap[String, Object]()

map.put("abc", List(s1,s2).toArray)

val gson = new Gson()

println( gson.toJson(map) )

判断json

def isGoodJson(json: String):Boolean = {

if(null == json) {

return false

}

val result = JSON.parseFull(json) match {

case Some(_: Map[String, Any]) => true

case None => false

case _ => false

}

result

}

spray-json

io.spray

spray-json_${scala.version}

1.3.2

val json = JsonParser(result).asJsObject()

println(json.getFields("name"))