This is my string:
{"array":[{"message":"test1","name":"test2","creation":"test3"},{"message":"test1","name":"test2","creation":"test3"}]}
And I want it get that array into a list of object in Kotlin app for Android.
I tried to do it using two examples from this site... So here is my code (res = that string):
val gson = Gson()
val obj = gson.fromJson(res, JsonObject::class.java)
val arr = obj.getAsJsonArray("array")
println(arr.toString())
val list1 : List<JThread> = gson.fromJson(arr, object : TypeToken<List<JThread>>() {}.type)
val list2 = gson.fromJson(arr, Array<JThread>::class.java).asList()
for (x in list1){
println(x.message)
}
for (x in list2){
println(x.message)
}
However I'm only getting null in x.message. I don't know what can go wrong.
I also tried changing arr to arr.toString() everywhere and that didn't work either.
Also JThread is:
object JThread {
var message: String? = null
var name: String? = null
var creation: String? = null }
This can be done without GSON or any other third party library:
#Throws(JSONException::class)
fun JSONObject.toMap(): Map<String, Any> {
val map = mutableMapOf<String, Any>()
val keysItr: Iterator<String> = this.keys()
while (keysItr.hasNext()) {
val key = keysItr.next()
var value: Any = this.get(key)
when (value) {
is JSONArray -> value = value.toList()
is JSONObject -> value = value.toMap()
}
map[key] = value
}
return map
}
#Throws(JSONException::class)
fun JSONArray.toList(): List<Any> {
val list = mutableListOf<Any>()
for (i in 0 until this.length()) {
var value: Any = this[i]
when (value) {
is JSONArray -> value = value.toList()
is JSONObject -> value = value.toMap()
}
list.add(value)
}
return list
}
Usage to convert JSONArray to List:
val jsonArray = JSONArray(jsonArrStr)
val list = jsonArray.toList()
Usage to convert JSONObject to Map:
val jsonObject = JSONObject(jsonObjStr)
val map = jsonObject.toMap()
More info is here
Use this code:
import com.google.gson.annotations.SerializedName
import com.google.gson.Gson
data class Array(
#SerializedName("message")
var message: String,
#SerializedName("name")
var name: String,
#SerializedName("creation")
var creation: String
)
data class Example(
#SerializedName("array")
var array: List<Array>? = null
)
private fun fromJson(json:String):Example{
return Gson().fromJson<Example>(json, Example::class.java)
}
PS: I made it with this site:http://www.jsonschema2pojo.org/
Related
"[[{"NameOfNote":"P","Height":"0","Alteration":"100","Frequency":"0.0","Finger":"0","String":"0","Time":"16","Dotted_Note":"0","ToBeDisplayed":"true"},{"NameOfNote":"P","Height":"0","Alteration":"100","Frequency":"0.0","Finger":"0","String":"0","Time":"16","Dotted_Note":"0","ToBeDisplayed":"true"}],[{"NameOfNote":"P","Height":"0","Alteration":"100","Frequency":"0.0","Finger":"0","String":"0","Time":"16","Dotted_Note":"0","ToBeDisplayed":"true"},{"NameOfNote":"P","Height":"0","Alteration":"100","Frequency":"0.0","Finger":"0","String":"0","Time":"16","Dotted_Note":"0","ToBeDisplayed":"true"}]]"
Above is my output
Below is my implementation
var mainJson = JSONArray()
for(i in 0..song_result.size-1){
var innerJSONArray = JSONArray()
for (j in 0..song_result[i].size -1){
var obj = JSONObject()
try {
obj.put("NameOfNote", song_result[i][j].NameOfNote)
obj.put("Height", song_result[i][j].Height)
obj.put("Alteration", song_result[i][j].Alteration)
obj.put("Frequency", song_result[i][j].Frequency)
obj.put("Finger", song_result[i][j].Finger)
obj.put("String", song_result[i][j].String)
obj.put("Time", song_result[i][j].Time)
obj.put("Dotted_Note", song_result[i][j].Dotted_Note)
obj.put("ToBeDisplayed", song_result[i][j].ToBeDisplayed)
} catch (e: JSONException) {
e.printStackTrace()
}
innerJSONArray.put(obj)
}
mainJson.put(innerJSONArray)
}
json is not encoded well let me solve your problem
add the gson lib from here
add this class
data class Root (
#SerializedName("NameOfNote") val nameOfNote : String,
#SerializedName("Height") val height : Int,
#SerializedName("Alteration") val alteration : Int,
#SerializedName("Frequency") val frequency : Double,
#SerializedName("Finger") val finger : Int,
#SerializedName("String") val string : Int,
#SerializedName("Time") val time : Int,
#SerializedName("Dotted_Note") val dotted_Note : Int,
#SerializedName("ToBeDisplayed") val toBeDisplayed : Boolean
)
Call this method
val obj= Root(nameOfNote = "name",height = 9,alteration = 7,frequency = 7.8,finger = 7,string = 7,time = 8,dotted_Note = 9,toBeDisplayed = false)
val json= Gson ().toJson(obj)
You can do this in for loop just rember to add in string dont replace
I want to save data acquired from Volley, But lambda used in VolleyRequest function(which gets json data from server) blocks it.
How should I change local variable that is in outside of lambda?
Thanks in advance.
class ConDataforReturn( val title:String , val imgDataList: ArrayList<ConImgData>)
fun getConData(context: Context, idx : String):ConDataforReturn{
val params = HashMap<String,String>()
var cd = arrayListOf<ConImgData>()
var title =""
params.put("package_idx",idx)
Log.e("idx size",idx.length.toString())
VolleyRequest(context,params,"https://dccon.dcinside.com/index/package_detail") { response ->
val answer = JSONObject(response)
var json = answer.getJSONArray("detail")
title = answer.getJSONObject("info").getString("title")
Log.d("title",title)//Prints right data
for (i in 0..(json.length() - 1)) {
val v = json.getJSONObject(i)
cd.add(ConImgData(v.getString("title"), v.getString("ext"), v.getString("path")))
}
}
return ConDataforReturn(title,cd)//returns ConDataforReturn("",arrayListOf<ConImgData>())
}
Here the the code from were you are calling this method
getConData(this, "id") { condata ->
}
Now, your method look like this,
fun getConData(context: Context, idx : String, returnConData : (condata : ConDataforReturn) -> Unit){
val params = HashMap<String,String>()
var cd = arrayListOf<ConImgData>()
var title =""
params.put("package_idx",idx)
Log.e("idx size",idx.length.toString())
VolleyRequest(context,params,"https://dccon.dcinside.com/index/package_detail") { response ->
val answer = JSONObject(response)
var json = answer.getJSONArray("detail")
title = answer.getJSONObject("info").getString("title")
Log.d("title",title)//Prints right data
for (i in 0..(json.length() - 1)) {
val v = json.getJSONObject(i)
cd.add(ConImgData(v.getString("title"), v.getString("ext"), v.getString("path")))
}
returnConData(ConDataforReturn(title,cd)) //returns ConDataforReturn("",arrayListOf<ConImgData>())
}
}
This is what my json looks like
{
"sub": "9",
"auth_time": 1559381757,
"idp": "idsrv",
"role": [
"Employer",
"Employee",
"Student"
],
"iss": "",
"aud": "",
"exp": 1574933757,
"nbf": 1559381757
}
This is the object I want to convert this Json into.
data class Claims (
#SerializedName("nameid") val nameId: String,
#SerializedName("unique_id") val uniqueId: String,
#SerializedName("sub") val sub: String,
#SerializedName("unifiedNumber") val unifiedNumber: String,
#SerializedName("role") var roleList: List<Role>
)
I wrote a custom Deserializer (which works in Java) for the List type
class RoleDeserializer : JsonDeserializer<List<Role>> {
private var roleId = 0
#Throws(JsonParseException::class)
override fun deserialize(json: JsonElement, typeOfT: Type, context: JsonDeserializationContext): MutableList<Role> {
val resultList = ArrayList<Role>()
if (json.isJsonArray) {
for (e in json.asJsonArray) {
resultList.add(Role(id = roleId++, name = e.asString))
}
} else if (json.isJsonObject) {
resultList.add(Role(id = roleId++, name = json.asString))
} else if (json.isJsonPrimitive) {
if ((json as JsonPrimitive).isString)
resultList.add(Role(id = roleId++, name = json.getAsString()))
} else {
throw RuntimeException("Unexpected JSON type: " + json.javaClass)
}
return resultList
}
}
This is how I register my type adapter
val listType: Type = object : TypeToken<List<Role>>() {}.type
val gson = GsonBuilder().registerTypeAdapter(listType, RoleDeserializer()).create()
val claims = gson.fromJson(stringJson, Claims::class.java)
I still get a parse exception stating that
java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column 161 path $.role[0]
and my RoleDeserializer is never called. Am I doing something wrong while registering the type adapter?
Try to replace
val listType: Type = object : TypeToken<List<Role>>() {}.type
with
val listType: Type = object : TypeToken<MutableList<Role>>() {}.type
The role is String array in JSON
Use this
#SerializedName("role") var roleList: List<String>
Instead of this
#SerializedName("role") var roleList: List<Role>
Try this
data class Claims (
#SerializedName("nameid") val nameId: String,
#SerializedName("unique_id") val uniqueId: String,
#SerializedName("sub") val sub: String,
#SerializedName("unifiedNumber") val unifiedNumber: String,
#SerializedName("role") var roleList: List<String>
)
I am working on an Android application in Kotlin which integrate Firebase.
Now I want to store my data (Kotlin data class) into Firebase Database.
Data Classes:
#Parcelize
data class Trip(
val fromAddress: String,
val toAddress: String,
val fromLocation: String,
val toLocation: String,
val orderUid: String
) : Parcelable
#Parcelize
data class Order(val trip: Trip, val date: Date, var status: OrderStatus, val userUid: String) : Parcelable {
var pickUpDate: Date? = null
var dropOffDate: Date? = null
var price: Double? = null
}
Fireabase Database write operation:
fun createNewOrder(
fromAddress: String,
toAddress: String,
fromLocation: Location,
toLocation: Location
) {
val fromGeoLocation = fromLocation.convertToGeoLocation()
val toGeoLocation = toLocation.convertToGeoLocation()
val userUid = sharedPreferences[CURRENT_USER_UID_KEY, ""]!!
val orderKey = databaseReference.child(DB_ORDERS_KEY).push().key
val tripKey = databaseReference.child(DB_TRIPS_KEY).push().key
val trip = orderKey?.let { createNewTrip(fromAddress, toAddress, it) }
val order = trip?.let { Order(it, Date(), OrderStatus.PENDING, userUid) }
if (trip != null && order != null && !userUid.isNullOrEmpty()) {
ordersGeoFire.setLocation(trip.fromGeoLocation, fromGeoLocation)
ordersGeoFire.setLocation(trip.toGeoLocation, toGeoLocation)
val allData = mutableMapOf<String, Any>()
allData["/$DB_TRIPS_KEY/$tripKey"] = trip?.convertToMap()
allData["/$DB_ORDERS_KEY/$orderKey"] = order?.convertToMap()
allData["/$DB_USERS_KEY/$userUid/$DB_ORDERS_KEY/$orderKey"] = true
databaseReference.updateChildren(allData)
}
}
I received this error:
com.google.firebase.database.DatabaseException: No properties to serialize found on class kotlin.Unit
Any suggestions?
The problem in your code is that the fileds inside your Trip class are not initialized. A recommended way in which you can create your model class would be:
class Trip(
val displayName: String = "",
val email: String = "",
val photoUrl: String = "",
val userId: String = ""
)
This is only what you need. And a way to create a new object of your Trip class, would be:
val trip = Trip(displayName, email, photoUrl, userId)
It was my mistake, because I was forget to add return type in my extensions convertToMap functions. Now they look like this:
fun Trip.convertToMap(): MutableMap<String, Any> {
val map = mutableMapOf<String, Any>()
map["fromAddress"] = fromAddress
map["toAddress"] = toAddress
map["fromGeoLocation"] = fromGeoLocation
map["toGeoLocation"] = toGeoLocation
map["orderUid"] = orderUid
return map
}
And also thanks to #Alex Mamo for his answer, it helps me in my investigation.
Now my code looks like this and works fine:
#Parcelize
data class Trip(
var fromAddress: String = "",
var toAddress: String = "",
var fromGeoLocation: String = "",
var toGeoLocation: String = "",
var orderUid: String = ""
) : Parcelable
#Parcelize
data class Order(
var trip: Trip? = null,
var date: Date? = null,
var status: OrderStatus? = null,
var userUid: String = ""
) : Parcelable {
var pickUpDate: Date? = null
var dropOffDate: Date? = null
var price: Double? = null
}
fun createNewOrder(
fromAddress: String,
toAddress: String,
fromLocation: Location,
toLocation: Location
): LiveData<Order> {
orderLiveData = MutableLiveData()
orderLiveData.value = null
val userUid = sharedPreferences[CURRENT_USER_UID_KEY, ""]!!
val orderKey = databaseReference.child(DB_ORDERS_KEY).push().key
val tripKey = databaseReference.child(DB_TRIPS_KEY).push().key
val trip = orderKey?.let { createNewTrip(fromAddress, toAddress, fromLocation, toLocation, it) }
val order = trip?.let { Order(it, Date(), OrderStatus.PENDING, userUid) }
if (trip != null && order != null && !userUid.isNullOrEmpty()) {
val allData = mutableMapOf<String, Any>()
allData["/$DB_TRIPS_KEY/$tripKey"] = trip.convertToMap()
allData["/$DB_ORDERS_KEY/$orderKey"] = order.convertToMap()
allData["/$DB_USERS_KEY/$userUid/$DB_ORDERS_KEY/$orderKey"] = true
databaseReference.updateChildren(allData) { databaseError, databaseReference ->
if (databaseError == null) orderLiveData.value = order
}
}
return orderLiveData
}
Hope this will be helpful
I have these classes written in kotlin, Location, and the rest is in the Application.kt
#RealmClass
open class Location(
#PrimaryKey
#SerializedName("id")
var id: Int = 0,
#SerializedName("city_name")
var city_name: String? = null,
#SerializedName("elevation")
var elevation: Int = 0,
#SerializedName("state_code")
var state_code: String? = null,
#SerializedName("state_name")
var state_name: String? = null,
#SerializedName("country_code")
var country_code: String? = null,
#SerializedName("country_name")
var country_name: String? = null
):RealmObject()
and the rest:
private fun loadStuff() {
val inputStream = this.resources.openRawResource(R.raw.city_json)
val jsonReader = JsonReader(InputStreamReader(inputStream, "UTF-8"))
val gson = Gson()
Realm.getDefaultInstance().executeTransactionAsync(Realm.Transaction { realm ->
val weatherList = gson.fromJson<List<Location>>(jsonReader , Array<Location>::class.java).toList()
//realm.insertOrUpdate(location)
jsonReader.endArray()
jsonReader.close()
}, Realm.Transaction.OnSuccess {
Log.d("TAG", "Success")
})
}
and I keep getting exception:
com.example.android.sunshine.data.Location[] cannot be cast to java.lang.Iterable
what am I doing wrong ?
the object looks like this:
[
{
"id":3040051,
"city_name":"les Escaldes",
"elevation":0,
"state_code":"08",
"state_name":"Parròquia d'Escaldes-Engordany",
"country_code":"AD",
"country_name":"Andorra"
},
{
"id":3041563,
"city_name":"Andorra la Vella",
"elevation":0,
"state_code":"07",
"state_name":"Parròquia d'Andorra la Vella",
"country_code":"AD",
"country_name":"Andorra"
}
]
This:
List<Location>
Is a List of Location. List implements Iterable.
This:
Array<Location>
is an Array of Location. Array does not implement Iterable.
The differences are bigger than that, but his is the one your error is for.
It was enough to swap List with Array and remove .toList() and it worked like magic