android - tutorial - kotlin vs java

kotlin.TypeCastException: null no se puede convertir al tipo com.midsizemango.databasekotlin.Note que no sea nulo

Question

Estoy tratando de codificar mi aplicación en Kotlin, pero la nula no se puede convertir al tipo no nulo y la aplicación se detiene cuando abro EditNoteActivity en EXTRA_NOTE probablemente.

Cualquier ayuda es muy apreciada

Código:

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
    }
}
}

Registros:

java.lang.RuntimeException: No se puede iniciar la actividad ComponentInfo {com.midsizemango.databasekotlin / com.midsizemango.databasekotlin.EditNoteActivity}: kotlin.TypeCastException: null no se puede convertir en un tipo no nulo com.midsizemango.dparo app.ActivityThread.performLaunchActivity (ActivityThread.java:2298) en android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:2360) en android.app.ActivityThread.access $ 800 (ActivityThread.java:144) H.handleMessage (ActivityThread.java:1278) en android.os.Handler.dispatchMessage (Handler.java:102) en android.os.Looper.loop (Looper.java:135) en android.app.ActivityThread.main (ActivityThread .java: 5221) en java.lang.reflect.Method.invoke (Método nativo) en java.lang.reflect.Method.invoke (Method.java:372) en com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run (ZygoteInit.java:899) en com.android.internal.os.ZygoteInit.main (ZygoteInit.java:694) Causado por: kotlin.TypeCastException: null no puede se convierte en un tipo no nulo com.midsizemango.databasekotlin.Note en com.midsizemango.databasekotlin.EditNoteActivity.onCreate (EditNoteActivity.kt: 82) en android.app.Activity.performCreate (Activity.java:5933) en androidroid.app .Instrumentation.callActivityOnCreate (Instrumentation.java:1105) en android.app.ActivityThread.performLaunchActivity (ActivityThread.java:2251) en android.app. (ActivityThread.java:144) en android.app.ActivityThread $ H.handleMessage (ActivityThread.java:1278) en android.os.Handler.dispatchMessage (Handler.java:102) en android.os.Looper.loop (Looper. java: 135) en android.app.ActivityThread.main (ActivityThread.java:5221) en java.lang.reflect.Method.invoke (Método nativo) en java.lang.reflect.Method.invoke (Method.java:372) en com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run (ZygoteInit.java:899) en com.android.internal.os.ZygoteInit.main (ZygoteInit.java:694)

Answer 1

En esta línea:

note = intent.getSerializableExtra(EXTRA_NOTE) as Note

Note es un tipo que no es nulo , por lo que la conversión a él desencadena una comprobación nula. Ya que está comparando note a null manualmente después, probablemente se refirió al operador de conversión segura , que produce un null si la expresión no es del tipo especificado en el lado derecho:

note = intent.getSerializableExtra(EXTRA_NOTE) as? Note