kotlin - 在文本编辑中设置文本''未找到结果''
问题描述
在修改我的代码时需要您的帮助，我正在尝试通过通过数据 json 搜索航班号来构建一个包含航班时刻表的应用程序。我正在使用编辑文本和 AsyncTask 以及自定义列表适配器列表视图。我的应用程序工作正常，但问题是当用户以错误的方式输入航班号时FATAL EXCEPTION。因为数据 json url 当用户输入正确的航班号时他有数据数组，其他方式如果用户输入错误的航班号数据 json url 他将返回数据 jsonjsonobject并且我得到FATAL EXCEPTION的是
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)
数据 json 如果输入正确 l 获取数据数组
{
"result": {
"request": {},
"response": {
"data": [
{
"identification": {
"id": null,
"row": 4849651452,
"callsign": null,
"codeshare": null
},
"status": {
"live": false,
"text": "Scheduled",
"icon": null,
"estimated": null,
"ambiguous": false
}
}
]
}
}
}
如果输入错误 l 获取数据 json 对象和致命异常
{
"result": {
"request": {},
"response": {
"data": null
}
}
}
类活动，包括列表适配器
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
}
}
当我FATAL EXCEPTION: main用这段代码在第 106 行发现主要问题时 val jsonArray = JSONArray(response.get("data").toString())
请我想用代码人回答，我想在用户输入错误信息时添加文本，他会响应示例“找不到航班，请确保航班号”
谢谢你
解决方案
原因：org.json.JSONException：类型为 org.json.JSONObject$1 的值 null 无法转换为 JSONArray
您应该检查是否getJSONArray为空
如果您的 Json，下面的代码将起作用"data":[]
val jsonData = response.getJSONArray("data")
if(jsonData.length()!=0)
{
// Do your work
}
供参考
您应该检查您的 Json 数据JSONArray或String.
Object dataVal= response.get("data");
if (dataValis is JSONArray)
{
// Your code
}
else
{
// null value
}