使用mobie数据时应用程序崩溃（3g / 4g）

我使用AsyncTask从我的服务器获取数据 .

我连接到wifi，它工作正常 .

但是当连接到移动数据（3g / 4g）时，它会崩溃（有时会很好） .

这是Logcat：

致命异常：AsyncTask＃2

这是代码：

inner class ReadContentUri : AsyncTask() {
    lateinit var content: StringBuilder

    private fun getHttp(P0: String){
        try {
            content = StringBuilder()
            val url = URL(P0)
            val urlConnection = url.openConnection() as HttpsURLConnection
            urlConnection.useCaches = false
            val inputStream = urlConnection.inputStream
            val inputStreamReader = InputStreamReader(inputStream)
            val bufferedReader = BufferedReader(inputStreamReader)

            var line: String?
            try {
                do {
                    line = bufferedReader.readLine()
                    if (line != null) {
                        content.append(line)
                    }
                } while (line != null)
                bufferedReader.close()
            } catch (e: Exception) {
                Log.d("ERROR", e.message)
            }
        }catch (e: Exception){}
    }

    override fun doInBackground(vararg params: String): String {
        val net = baseContext.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
        val netInfo = net.activeNetworkInfo
        if(netInfo != null && netInfo.isConnected) {
            when (netInfo.type) {
                ConnectivityManager.TYPE_WIFI -> {
                    getHttp(params[0])
                    if(content.toString().isNotBlank())
                        publishProgress(content.toString())
                    else
                        publishProgress("Error network")
                }
                ConnectivityManager.TYPE_MOBILE -> {
                    getHttp(params[0])
                    if(content.toString().isNotBlank())
                        publishProgress(content.toString())
                    else
                        publishProgress("Error network")
                }
                else -> publishProgress("Error network")
            }
        }else
            publishProgress("No network")
        return ""
    }

    @SuppressLint("SetTextI18n", "RtlHardcoded")
    override fun onProgressUpdate(vararg values: String?) {
        if(values[0] !== "No network" && values[0] !== "Error network" && values[0] != null) {
            val obj = JSONObject(values[0])
            val status: String = obj.getString("status")
            light = obj
            if (status == "true") {
                val i = Intent(this@Main3Activity, HomeService::class.java)
                i.putExtra("content", getToken())
                startService(i)
                update = "updated"
                light_lable.visibility = View.VISIBLE
                light_lable.text = "Updated"

                val toggle = ActionBarDrawerToggle(
                        this@Main3Activity, drawer_layout, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close)
                drawer_layout.addDrawerListener(toggle)
                toggle.syncState()
                nav_view.setNavigationItemSelectedListener(this@Main3Activity)
                drawer_layout.openDrawer(Gravity.LEFT)
                setInfo()
            }
        }else if (values[0] == "No network"){
            light_lable.text = "No network"
            light_lable.setTextColor(resources.getColor(R.color.ColorSecondary))
        }else{
            light_lable.text = "Error network"
            light_lable.setTextColor(resources.getColor(R.color.ColorSecondary))
        }
    }
}

我该怎么办？