Android活动恢复上的BadParcelableException

Question

I have an activity that loads a fragment in it's onResume method

override fun onResume() {
    super.onResume()

    loadDietFragment()
}

fun loadDietFragment() {
  val uri = Uri.parse("${DatabaseContract.CONTENT_URI}/current")
  val currentDietCursor = contentResolver.query(uri , null, null, null, null )
  if(currentDietCursor.count > 0) {
      currentDietCursor.moveToFirst()
      currentDiet = DietEntity(currentDietCursor)
      currentDietCursor.close()
      loadHomeFragment()
      return
  }
}

private fun loadHomeFragment() {
        val transaction = supportFragmentManager.beginTransaction()
        val fragment = HomeFragment()
        val arguments = Bundle()
        arguments.putParcelable("diet", currentDiet)
        fragment.arguments = arguments

        transaction.replace(R.id.HomeFrameLayout, fragment)

        transaction.addToBackStack(null)
        transaction.commit()
    }

And then in the Fragment I have:

override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        currentDiet = arguments.getParcelable("diet")
        preferences = PreferenceManager.getDefaultSharedPreferences(activity)
    }

It seems fine and it's working but there are some rare cases when I receive a BadParcelableException with this stack trace:

   java.lang.RuntimeException: 
     at android.app.ActivityThread.performLaunchActivity (ActivityThread.java:2560)
     at android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:2630)
     at android.app.ActivityThread.-wrap11 (ActivityThread.java)
     at android.app.ActivityThread$H.handleMessage (ActivityThread.java:1482)
     at android.os.Handler.dispatchMessage (Handler.java:111)
     at android.os.Looper.loop (Looper.java:207)
     at android.app.ActivityThread.main (ActivityThread.java:5736)
     at java.lang.reflect.Method.invoke (Native Method)
     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:907)
     at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:768)
   Caused by: android.os.BadParcelableException: 
     at android.os.Parcel.readParcelableCreator (Parcel.java:2415)
     at android.os.Parcel.readParcelable (Parcel.java:2337)
     at android.os.Parcel.readValue (Parcel.java:2243)
     at android.os.Parcel.readArrayMapInternal (Parcel.java:2592)
     at android.os.BaseBundle.unparcel (BaseBundle.java:221)
     at android.os.Bundle.getParcelable (Bundle.java:786)
     at com.healthier_life.a90_days_diet.fragments.HomeFragment.onCreate    (HomeFragment.kt:59)
     at android.support.v4.app.Fragment.performCreate (Fragment.java:2339)
     at android.support.v4.app.FragmentManagerImpl.moveToState (FragmentManager.java:1377)
     at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState    (FragmentManager.java:1740)
     at android.support.v4.app.FragmentManagerImpl.moveToState (FragmentManager.java:1809)
     at android.support.v4.app.FragmentManagerImpl.dispatchStateChange    (FragmentManager.java:3217)
     at android.support.v4.app.FragmentManagerImpl.dispatchCreate (FragmentManager.java:3166)
     at android.support.v4.app.FragmentController.dispatchCreate (FragmentController.java:181)
     at android.support.v4.app.FragmentActivity.onCreate (FragmentActivity.java:319)
     at android.support.v7.app.AppCompatActivity.onCreate (AppCompatActivity.java:84)
     at com.healthier_life.a90_days_diet.activities.BaseActivity.onCreate    (BaseActivity.kt:18)
     at com.healthier_life.a90_days_diet.MainActivity.onCreate (MainActivity.kt:46)
     at android.app.Activity.performCreate (Activity.java:6278)
     at android.app.Instrumentation.callActivityOnCreate (Instrumentation.java:1136)
     at android.app.ActivityThread.performLaunchActivity (ActivityThread.java:2513)

I cannot consistently reproduce it. It happens a few times a day(Google Play statistics) and I was able to see it on my phone just once. I haven't been used the app for a few hours. I have clicked on the app icon and it trowed the exception.

Is there anything that's wrong in the current example? I am open for suggestions either how to fix the bug or how to reproduce it consistently. Thanks!

EDIT: I have forgot to share the DietEntity class: https://pastebin.com/EkT79ubT It's in pastebin since It doesn't allow me to put that much code in a post with that amount of text.

Answer 1

Android Studio actually has a code generation option for Parcelable implementations. The main thing that sticks out to me is that your CREATOR may not be implemented correctly. Try doing it as a companion object. There's also no need to name the variable a reserved word like in and have to use back ticks all the time.

override fun writeToParcel(parcel: Parcel, flags: Int) {
    parcel.writeInt(id)
    parcel.writeLong(startDate.millis)
    parcel.writeLong(endDate.millis)
    parcel.writeString(type.toString())
    parcel.writeByte(if (skipWaterDay1) 1 else 0)
    parcel.writeByte(if (skipWaterDay2) 1 else 0)
    parcel.writeByte(if (skipWaterDay3) 1 else 0)
}

override fun describeContents(): Int = 0

companion object CREATOR : Parcelable.Creator<DietEntity> {
    override fun createFromParcel(parcel: Parcel): DietEntity = DietEntity(parcel)
    override fun newArray(size: Int): Array<DietEntity?> = arrayOfNulls(size)
}