I am trying to get a specific value from my JSON data. I could successfully call the entire json data,jsonOutput
. But the thing is when I call a specific value in the jsonOutput, it shows me nullPointerError
. I do not know why I lost the data when I call my data class. I marked the part I lost them with The problem occurs here
. How can I get adminArea1
?
I shared one data class as a sample. You can create the data classes with "Kotlin data class File from JSON".
I referred to many answers and examples but was hard to know the reason.
My code
class MainActivity : AppCompatActivity() {
private lateinit var binding: ActivityMainBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = DataBindingUtil.setContentView(this, R.layout.activity_main)
binding.networkBtn.setOnClickListener(View.OnClickListener {
var thread = NetworkThread()
thread.start()
})
}
inner class NetworkThread : Thread() {
override fun run() {
var url =
URL("https://www.mapquestapi.com/geocoding/v1/reverse?key=LBK8QWxDPYHfmeYVlEP1IO3BVbWHyznB&" +
"location=Your_laptitue,Your_longitute&includeRoadMetadata=true&includeNearestIntersection=true")
var countryCodeBufferedReader =
BufferedReader(InputStreamReader(url.openConnection().getInputStream()))
var stringBuffer = StringBuffer()
do {
var string = countryCodeBufferedReader.readLine()
if (string != null) {
stringBuffer.append(string)
}
} while (string != null)
var jsonObject = JSONObject(stringBuffer.toString())
val gson: Gson = GsonBuilder().setPrettyPrinting().create()
val jsonOutput: String = gson.toJson(jsonObject)
//The problem occurs here
var countryData = gson.fromJson(jsonOutput, NameValuePairsXXXXX::class.java)
val jsonOutput2 = countryData.adminArea1
Log.d("jsonOutput", jsonOutput)
Log.d("jsonOutput2", jsonOutput2)
runOnUiThread {
binding.lapLonText.text = jsonOutput2
}
}
}
}
Data class
2
Answers
It was caused due to API communication. I solved my problem by putting okHttpClient. I added the code to help anybody having the same question.
Use this class and use Response data class to parse json,
var countryData = gson.fromJson(jsonOutput, Reponse::class.java)