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I am trying to code my app in Kotlin, but I am getting null cannot be casted to non-null type and app force stops when I open
EditNoteActivity
at
EXTRA_NOTE
probably.
Any Help is Highly Appreciated
Code:
class EditNoteActivity : AppCompatActivity() {
var note: Note? = null
private val editNote: TextView? = null
private val fabdrwble: Boolean? = null
private val notesData: MutableList<Note>? = null
private var databaseHelper: DatabaseHelper? = null
private val save: Boolean? = null
private var saveButton: FloatingActionButton? = null
private val tint: ColorStateList? = null
internal var mRowId: Long? = null
internal var spinner: Spinner? = null
internal var spinnertext: String? = null
internal var fav: Int = 0
internal var mSharedFromIntentFilter = false
internal var editTitle: EditText? = null
internal var editContent: EditText? = null
internal var inputlayoutTitle: TextInputLayout? = null
internal var inputlayoutContent: TextInputLayout? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_edit_note)
var toolbar = findViewById(R.id.toolbar_edit) as Toolbar?
setSupportActionBar(toolbar)
if (supportActionBar != null)
supportActionBar!!.setDisplayHomeAsUpEnabled(true)
databaseHelper = DatabaseHelper(applicationContext)
inputlayoutTitle = findViewById(R.id.inputlayoutTitle) as TextInputLayout?
inputlayoutContent = findViewById(R.id.inputlayoutContent) as TextInputLayout?
editTitle = findViewById(R.id.note_title) as EditText
editContent = findViewById(R.id.note_content) as EditText?
val bundle = intent.extras
val s = bundle.getString("edit")
if (s == "add") {
window.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_VISIBLE)
} else if (s == "editv") {
window.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN)
note = intent.getSerializableExtra(EXTRA_NOTE) as Note
if (note != null) {
editTitle?.setText(note!!.getTitle())
editContent?.setText(note!!.getContent())
} else {
note = Note()
//note.setUpdatedAt(new Date());
saveButton = findViewById(R.id.add_edit_button) as FloatingActionButton?
saveButton!!.setOnClickListener {
if (isNoteFormOk) {
setNoteResult()
finish()
} else
validateNoteForm()
var ll = findViewById(R.id.llmain) as LinearLayout?
var ll1 = findViewById(R.id.ll1) as LinearLayout?
/*if(note.getColor() == Color.TRANSPARENT){
selectedColor = preselect;
}else {
selectedColor = note.getColor();
getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
systemBarTintManager = new SystemBarTintManager(this);
systemBarTintManager.setStatusBarTintEnabled(true);
ll.setBackgroundColor(selectedColor);
ll1.setBackgroundColor(selectedColor);
toolbar.setBackgroundColor(note.getColor());
systemBarTintManager.setStatusBarTintColor(selectedColor);*/
override fun onResume() {
super.onResume()
override fun onOptionsItemSelected(item: MenuItem): Boolean {
when (item.itemId) {
android.R.id.home -> {
onBack()
return true
case R.id.speech:
try {
displaySpeechRecognizer();
} catch (ActivityNotFoundException e) {
Intent browserIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("https://market.android.com/details?id=com.google.android.googlequicksearchbox"));
startActivity(browserIntent);
return true;*/
else -> return super.onOptionsItemSelected(item)
private fun displaySpeechRecognizer() {
val intent = Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH)
intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL, RecognizerIntent.LANGUAGE_MODEL_FREE_FORM)
startActivityForResult(intent, SPEECH_REQUEST_CODE)
override fun onActivityResult(requestCode: Int, resultCode: Int,
data: Intent) {
if (requestCode == SPEECH_REQUEST_CODE && resultCode == Activity.RESULT_OK) {
val results = data.getStringArrayListExtra(RecognizerIntent.EXTRA_RESULTS)
val spokenText = results[0]
editContent?.setText(spokenText)
if (requestCode == RequestResultCode.REQUEST_CODE_ADD_NOTE) {
if (resultCode == Activity.RESULT_OK) {
addNote(data)
private val isNoteFormOk: Boolean
get() {
val title = editTitle?.text.toString()
return !(title == null || title.trim { it <= ' ' }.length == 0)
private fun validateNoteForm() {
var msg: String? = null
if (isNullOrBlank(editTitle?.text.toString())) {
msg = "Title Required"
inputlayoutTitle?.error = "Title is Missing"
if (msg != null) {
Toast.makeText(applicationContext, msg, Toast.LENGTH_LONG).show()
private fun setNoteResult() {
note!!.setTitle(editTitle?.text.toString().trim { it <= ' ' })
note!!.setContent(editContent?.text.toString().trim { it <= ' ' })
//note.setUpdatedAt(new Date());
val intent = Intent()
intent.putExtra(EXTRA_NOTE, note)
setResult(Activity.RESULT_OK, intent)
//addNote(intent);
Toast.makeText(this@EditNoteActivity, "Note Saved.", Toast.LENGTH_LONG).show()
private fun onBack() {
if (isNoteFormOk) {
if (editTitle?.text.toString() == note!!.getTitle() && editContent?.text.toString() == note!!.getContent()) {
setResult(Activity.RESULT_CANCELED, Intent())
finish()
} else {
AlertDialog.Builder(this@EditNoteActivity)
.setTitle("Save")
.setMessage("Do You Want to Save Note")
.setPositiveButton("SAVE") { dialog, which ->
setNoteResult()
finish()
}.setNegativeButton("CANCEL") { dialog, which ->
setResult(Activity.RESULT_CANCELED, Intent())
finish()
}.show()
} else {
setResult(Activity.RESULT_CANCELED, Intent())
finish()
private fun addNote(data: Intent) {
val note = data.getSerializableExtra(EXTRA_NOTE) as Note
val noteId = databaseHelper!!.createNote(note)
note.setId(noteId)
override fun onBackPressed() {
onBack()
val intentHome = Intent(this@EditNoteActivity, MainActivity::class.java)
intentHome.flags = Intent.FLAG_ACTIVITY_CLEAR_TOP
intentHome.putExtra(EXTRA_NOTE, note)
setResult(Activity.RESULT_OK, intentHome)
companion object {
private val EXTRA_NOTE = "EXTRA_NOTE"
private val SPEECH_REQUEST_CODE = 0
fun isNullOrBlank(str: String?): Boolean {
return str == null || str.trim { it <= ' ' }.length == 0
Logs:
java.lang.RuntimeException: Unable to start activity ComponentInfo{
com.midsizemango.databasekotlin/com.midsizemango.databasekotlin.EditNoteActivity}:
kotlin.TypeCastException: null cannot be cast to non-null type
com.midsizemango.databasekotlin.Note
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: kotlin.TypeCastException: null cannot be cast to non-null type com.midsizemango.databasekotlin.Note
at com.midsizemango.databasekotlin.EditNoteActivity.onCreate(EditNoteActivity.kt:82)
at android.app.Activity.performCreate(Activity.java:5933)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:694)
Note is a non-null type, so the cast to it triggers a null check. Since you're comparing note to null manually afterwards, probably you meant the safe cast operator, which yields null if the expression is not of the type specified in the right-hand side:
note = intent.getSerializableExtra(EXTRA_NOTE) as? Note
–
–
Beware, this answer relates only to some very special cases.
On Kotlin/JS there is fun <T> Any?.unsafeCast(): T extension which "reinterprets this value as a value of the specified type T without any actual type checking".
And, primarily for performance reasons, it was ported to Kotlin/JVM in https://github.com/JakeWharton/confundus with help of a custom compiler plugin which just removes all calls to unsafeCast() in bytecode.
The unsafeCast() can also be used to abuse compiler nullability checks in case of misalignment of nullability contracts between Kotlin and Java code in some legacy integrations.
–
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