scala - Play Framework: How to sort JSON alphabetically -

given following json...

{    "z": 100,    "b": 50,    "q": 12 } 

how sort keys alphabetically?

simple enough, (obviously) need make sure have jsobject.

val js = json.parse("""{    "z": 100,    "b": 50,    "q": 12 }""")  val jsobject = js.as[jsobject] // not safe, bear me 

the fields stored in field called fields seq[(string, jsvalue)].

scala> jsobject.fields res5: seq[(string, play.api.libs.json.jsvalue)] = listbuffer((z,100), (b,50), (q,12)) 

we can make new jsobject same fields, except sorted.

scala> jsobject(jsobject.fields.sortby(_._1)) res6: play.api.libs.json.jsobject = {"b":50,"q":12,"z":100} 

earlier, mentioned using as[jsobject] unsafe, because if our jsvalue array or string, throw exception. safer way handle jsvalue here pattern match on jsobject , sort it, , nothing other type. simple enough create method recursively sorts keys:

def sortjs(js: jsvalue): jsvalue = js match {     case jsobject(fields) => jsobject(fields.sortby(_._1).map { case (k, v) => (k, sortjs(v)) })     case _ => js }  val js = json.parse("""{    "z": 100,    "b": {"k": 1, "j": 3, "i": 98},    "q": 12 }""")  scala> sortjs(js) res8: play.api.libs.json.jsvalue = {"b":{"i":98,"j":3,"k":1},"q":12,"z":100}