When starting the application, I was trying to create preferences and edit its values. The getDefaultHostName() method threw a Null Pointer Exception. Below, there is a code sample, if anyone can help.
Thank you..
val pref = PreferenceManager.getDefaultSharedPreferences(this)
if (TextUtils.isEmpty(pref.getString(Utils.PREFS_HOST_NAME, null))) {
// No preferences found. Save default values.
val editor = pref.edit()
editor.putString(Utils.PREFS_HOST_NAME, getDefaultHostName())
editor.putBoolean(Utils.PREFS_USE_TLS, getDefaultTLS())
editor.apply()
}
private val sContext: MyApp? = null
fun getDefaultHostName(): String {
return sContext!!.resources
.getString(if (isEmulator()) R.string.emulator_host_name else R.string.default_host_name)
}
<string name="default_host_name">Default host name</string>
Application class extends DefaultLifecycleObserver
class MyApp : Application(), DefaultLifecycleObserver {
lateinit var userPreferences: UserPreferencesRepository
private val sContext: MyApp? = null
private var sContactsObserver: ContentObserver? = null
// The Tinode cache is linked from here so it's never garbage collected.
private val sCache: Cache? = null
private var sVideoCache: SimpleCache? = null
private var sAppVersion: String? = null
private var sAppBuild = 0
companion object {
var simpleCache: SimpleCache? = null
private val TAG: String =
GLOBAL_TAG + " " + MyApp::class.java.simpleName
@get:Synchronized
lateinit var instance: MyApp private set
/*Vid*/
// 256 MB.
private val PICASSO_CACHE_SIZE: Int = 1024 * 1024 * 256
private val VIDEO_CACHE_SIZE = 1024 * 1024 * 256
private var sContactsObserver: ContentObserver? = null
// The Tinode cache is linked from here so it's never garbage collected.
private var sCache: Cache? = null
private var sVideoCache: SimpleCache? = null
}
}
override fun onCreate() {
super<Application>.onCreate()
instance = this
try {
val pi = packageManager.getPackageInfo(packageName, 0)
instance.sAppVersion = pi.versionName
if (TextUtils.isEmpty(instance.sAppVersion)) {
instance.sAppVersion = BuildConfig.VERSION_NAME
}
instance.sAppBuild = pi.versionCode
if (instance.sAppBuild <= 0) {
instance.sAppBuild = BuildConfig.VERSION_CODE
}
} catch (e: PackageManager.NameNotFoundException) {
Log.w(MyApp.TAG, "Failed to retrieve app version", e)
}
FirebaseCrashlytics.getInstance().setCrashlyticsCollectionEnabled(!BuildConfig.DEBUG)
val br: BroadcastReceiver = object : BroadcastReceiver() {
override fun onReceive(context: Context, intent: Intent) {
val token = intent.getStringExtra("token")
if (token != null && token != "") {
Cache.tinode!!.setDeviceToken(token)
}
}
}
val lbm = LocalBroadcastManager.getInstance(this)
lbm.registerReceiver(br, IntentFilter("FCM_REFRESH_TOKEN"))
lbm.registerReceiver(
HangUpBroadcastReceiver(),
IntentFilter(Const.INTENT_ACTION_CALL_CLOSE)
)
createNotificationChannels()
ProcessLifecycleOwner.get().lifecycle.addObserver(this)
val pref = PreferenceManager.getDefaultSharedPreferences(this)
if (TextUtils.isEmpty(pref.getString(Utils.PREFS_HOST_NAME, null))) {
val editor = pref.edit()
editor.putString(Utils.PREFS_HOST_NAME, getDefaultHostName())
editor.putBoolean(Utils.PREFS_USE_TLS, getDefaultTLS())
editor.apply()
}
WorkManager.getInstance(this).pruneWork()
val client: OkHttpClient = OkHttpClient.Builder()
.cache(
okhttp3.Cache(
createDefaultCacheDir(this)!!,
MyApp.PICASSO_CACHE_SIZE.toLong()
)
)
.addInterceptor(Interceptor { chain: Interceptor.Chain ->
val tinode: Tinode = Cache.tinode!!
val picassoReq = chain.request()
val headers: Map<String?, String?>
if (tinode.isTrustedURL(picassoReq.url.toUrl())) {
headers = tinode.requestHeaders
var builder: okhttp3.Request.Builder = picassoReq.newBuilder()
for ((key, value) in headers) {
builder = builder.addHeader(key, value)
}
return@Interceptor chain.proceed(builder.build())
} else {
return@Interceptor chain.proceed(picassoReq)
}
})
.build()
Picasso.setSingletonInstance(Picasso.Builder(this)
.requestTransformer { request: Request ->
if (request.uri != null && Tinode.isUrlRelative(request.uri.toString())) {
val url: URL = Cache.tinode!!.toAbsoluteURL(request.uri.toString())!!
if (url != null) {
return@requestTransformer request.buildUpon()
.setUri(Uri.parse(url.toString())).build()
}
}
request
}
.downloader(OkHttp3Downloader(client))
.build())
val cm = getSystemService(CONNECTIVITY_SERVICE) as ConnectivityManager
?: return
val req =
NetworkRequest.Builder().addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
.build()
cm.registerNetworkCallback(req, object : ConnectivityManager.NetworkCallback() {
override fun onAvailable(network: Network) {
super.onAvailable(network)
if (!TextUtils.isEmpty(BaseDb.instance!!.uid)) {
// Connect right away if UID is available.
Cache.tinode!!.reconnectNow(true, false, false)
}
}
})
}
get context method
fun getAppContext(): Context? {
return sContext
}
Process: com.elto.date, PID: 31344 java.lang.RuntimeException: Unable to create application com.elto.date.lightDark.MyApp: java.lang.NullPointerException at android.app.ActivityThread.handleBindApplication(ActivityThread.java:7109) at android.app.ActivityThread.access$1600(ActivityThread.java:271) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2134) at android.os.Handler.dispatchMessage(Handler.java:106) at android.os.Looper.loopOnce(Looper.java:210) at android.os.Looper.loop(Looper.java:299) at android.app.ActivityThread.main(ActivityThread.java:8319) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:556) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1038) Caused by: java.lang.NullPointerException at com.elto.date.lightDark.MyApp.getDefaultHostName(MyApp.kt:240) at com.elto.date.lightDark.MyApp.onCreate(MyApp.kt:141) at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1212) at android.app.ActivityThread.handleBindApplication(ActivityThread.java:7103) at android.app.ActivityThread.access$1600(ActivityThread.java:271) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2134) at android.os.Handler.dispatchMessage(Handler.java:106) at android.os.Looper.loopOnce(Looper.java:210) at android.os.Looper.loop(Looper.java:299) at android.app.ActivityThread.main(ActivityThread.java:8319) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:556) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1038)
NullPointerException, 2) Please include the code that initializes thesContextproperty.