set text '' no result found '' in text edit - kotlin

Question

In need your help in modifying my code, I am trying to build an application that contains a flight schedule by searching on a flight number via data json . l am using edit text and AsyncTask and custom list adapter list view .My application works fine, but the problem is when the user enters the flight number in wrong way l got FATAL EXCEPTION . because data json url he has data array when user enters correct flight number , other ways if user enters wrong flight number the data json url he will back data json in jsonobject and l get FATAL EXCEPTION is
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.iraqairoirt.iraqairports, PID: 5380
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1386)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1496)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1386) 
Caused by: org.json.JSONException: Value null of type org.json.JSONObject$1 cannot be converted to JSONArray
at org.json.JSON.typeMismatch(JSON.java:111)
at org.json.JSONArray.<init>(JSONArray.java:96)
at org.json.JSONArray.<init>(JSONArray.java:108)
at com.iraqairoirt.iraqairports.BaghdadAirport.FlightSearch$Arr.handleJson(FlightSearch.kt:106)
at com.iraqairoirt.iraqairports.BaghdadAirport.FlightSearch$Arr.onPostExecute(FlightSearch.kt:90)
at com.iraqairoirt.iraqairports.BaghdadAirport.FlightSearch$Arr.onPostExecute(FlightSearch.kt:58)
at android.os.AsyncTask.finish(AsyncTask.java:660)
at android.os.AsyncTask.-wrap1(AsyncTask.java)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:677)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6776)
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1496) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1386) 
data json if input is correct l get data array
{
"result": {
"request": {},
"response": {
"data": [
{
"identification": {
"id": null,
"row": 4849651452,
"callsign": null,
"codeshare": null
},
"status": {
"live": false,
"text": "Scheduled",
"icon": null,
"estimated": null,
"ambiguous": false
}
}
]
}
}
}
if input is wrong l get data json object and fatal EXCEPTION
{
"result": {
"request": {},
"response": {
"data": null
}
}
}
class activity including list adapter
class FlightSearch : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_flight_search)
flightlistlaout.bringToFront()
}
fun getflightsearchresult(view:View){
val FlightNumber=flightnumbertext.text.toString()
// val auto=autoCompleteTextView.text.toString()
if(FlightNumber.trim().length>0) {
val url = "flight/list.json?query="+FlightNumber+"&fetchBy=flight&page=1&limit=100&token="
Arr().execute(url)
Toast.makeText(applicationContext, "Message : ", Toast.LENGTH_SHORT).show()
}else{
Toast.makeText(applicationContext, "Please enter some message! ", Toast.LENGTH_SHORT).show()
}
}
inner class Arr : AsyncTask<String, String, String>() {
override fun onPreExecute() {
super.onPreExecute()
}
// for build connection
override fun doInBackground(vararg url: String?): String {
var text: String
val connection = URL(url[0]).openConnection() as HttpURLConnection
connection.connectTimeout = 700
try {
connection.connect()
text = connection.inputStream.use { it.reader().use { reader -> reader.readText() } }
} finally {
connection.disconnect()
}
return text
}
override fun onPostExecute(result: String?) {
super.onPostExecute(result)
handleJson(result)
}
override fun onProgressUpdate(vararg text: String?) {
}
#SuppressLint("WrongViewCast")
private fun handleJson(jsonString: String?) {
val jsonObj = JSONObject(jsonString)
val result = jsonObj.getJSONObject("result")
val response = result.getJSONObject("response")
val jsonArray = JSONArray(response.get("data").toString())
val list = ArrayList<FlightShdu>()
var x = 0
while (x < jsonArray.length()) {
val jsonObject = jsonArray.getJSONObject(x)
list.add(
FlightShdu(
jsonObject.getJSONObject("identification").getJSONObject("number").getString("default"),
jsonObject.getJSONObject("airline").getString("name"),
jsonObject.getJSONObject("status").getJSONObject("generic").getJSONObject("status").getString(
"text"
),
jsonObject.getJSONObject("airline").getJSONObject("code").getString("icao"),
jsonObject.getJSONObject("time").getJSONObject("scheduled").getString("arrival"),
jsonObject.getJSONObject("airport").getJSONObject("origin").getJSONObject("code").getString(
"iata"
x++
}
list.forEach(::println)
var adapter = FlightSearchAdpater(this#FlightSearch, list)
flightsearchlists.adapter = adapter
}
}
}
class FlightSearchAdpater (val context: Context, val list: ArrayList<FlightShdu>): BaseAdapter() {
#SuppressLint("ViewHolder", "NewApi", "WrongViewCast")
override fun getView(p0: Int, convertView: View?, parent: ViewGroup?): View {
val view : View = LayoutInflater.from(context).inflate(R.layout.baghdad_arrivel_list,parent,false)
val list = list[p0]
val LogoAriline = view.findViewById(R.id.logo_image) as ImageView
val status = view.findViewById(R.id.ali_id) as AppCompatTextView
val Airport = view.findViewById(R.id.airportid) as AppCompatTextView
val code = view.findViewById(R.id.code_id) as AppCompatTextView
val TimeFlight = view.findViewById(R.id.time_id) as AppCompatTextView
val checkiflive = view.checkifliveTextId
view.callsign_id.text=list.Callsign
view.airline_id.text=list.Airline
code.text = list.code
view.ali_id.text=list.Stauts
status.text= list.Stauts
TimeFlight.text = getDateTime(list.TimeFlight)
Picasso.with(context).load(Uri.parse("/data/operators/"+status.text.toString()+"_logo0.png"))
.error(R.drawable.logo).into(LogoAriline)
Airport.text= list.Airport
view.model_id.text=list.Model
checkiflive.text=list.IfLive
private fun getDateTime(s: String): String? {
try {
val sdf = SimpleDateFormat("EE, MMM d KK:mm a")
val netDate = Date(s.toLong() * 1000)
return sdf.format(netDate)
} catch (e: Exception) {
return e.toString()
}
}
override fun getItem(p0: Int): Any {
return list [p0]
}
override fun getItemId(p0: Int): Long {
return p0.toLong()
}
override fun getCount(): Int {
return list.size
}
}
when l track FATAL EXCEPTION: main found the main problem in line 106 with this code val jsonArray = JSONArray(response.get("data").toString())
please l want answer with code guys , l want add text when the user enters wrong information he get respond example "no flights found please make sure about the flight number "
thank you

Answer 1

Caused by: org.json.JSONException: Value null of type
org.json.JSONObject$1 cannot be converted to JSONArray
You should check getJSONArray is null or not
Below code will work if Your Json "data":[]
val jsonData = response.getJSONArray("data")
if(jsonData.length()!=0)
{
// Do your work
}
FYI
You should check your Json data JSONArray or String.
Object dataVal= response.get("data");
if (dataValis is JSONArray)
{
// Your code
}
else
{
// null value
}

Answer 2

l found this way and its working fine
private fun handleJson(jsonString: String?) {
val jsonObj = JSONObject(jsonString)
val result = jsonObj.getJSONObject("result")
val response = result.getJSONObject("response")
if (jsonObj is JSONArray) {
val jsonArray= response.getJSONArray("data")
val list = ArrayList<FlightShdu>()
var x = 0
while (x < jsonArray.length()) {
val jsonObject = jsonArray.getJSONObject(x)
list.add(
FlightShdu(
jsonObject.getJSONObject("identification").getJSONObject("number").getString("default"),
jsonObject.getJSONObject("airline").getString("name"),
jsonObject.getJSONObject("status").getJSONObject("generic").getJSONObject("status").getString(
"text"
),
)
)
x++
}
list.forEach(::println)
var adapter = FlightSearchAdpater(this#FlightSearch, list)
flightsearchlists.adapter = adapter
}else if(jsonObj is JSONObject){
val response = result.getJSONObject("response")
if(response.isNull("data")){
Toast.makeText(applicationContext, "Please enter currect flight number", Toast.LENGTH_SHORT).show()
}
}
}