Serializable parcelable issue: RuntimeException: Parcelable encountered IOException writing serializable object

问题

Folks, I have simplest class which I want to be Parcelable. I'm doing it in following way:

public class MyField implements Serializable, Parcelable
{

    public MyField()
    {
    }


    //************************************************
    // Parcelable methods
    //************************************************
    public int describeContents() {return 0; };

    public void writeToParcel(Parcel out, int flags)
    {
        out.writeInt(this.describeContents());
        out.writeSerializable(this);
    }

    @SuppressWarnings("redundant")       
    public Parcelable.Creator<MyField> CREATOR
            = new Parcelable.Creator<MyField>()
    {
        public MyField createFromParcel(Parcel in)
        {
            int description=in.readInt();
            Serializable s=in.readSerializable();
            switch(description)
            {
                case 0:
                    return (MyField )s;
                default:
                    return null;
            }
        }

        public MyField[] newArray(int size)
        {
            return new MyField[size];
        }
    };
}

Simple, heh? Yes, looks like. But when I try to send my class object to another activity as parcel object like:

    intent=new Intent(activity, SendMessageActivity.class);
    MyField fld=new MyField();
    intent.putExtra("to", (Parcelable )fld);
    activity.startActivity(intent);

I'm getting following exception:

java.lang.RuntimeException: Parcelable encountered IOException writing serializable object (name = ru.ivanovpv.android.storage.MyField)
at android.os.Parcel.writeSerializable(Parcel.java:1131)
at ru.ivanovpv.android.storage.MyField.writeToParcel(MyField.java:58)
at android.os.Parcel.writeParcelable(Parcel.java:1106)
at android.os.Parcel.writeValue(Parcel.java:1029)
at android.os.Parcel.writeMapInternal(Parcel.java:469)
at android.os.Bundle.writeToParcel(Bundle.java:1445)
at android.os.Parcel.writeBundle(Parcel.java:483)
at android.content.Intent.writeToParcel(Intent.java:5237)
at android.app.ActivityManagerProxy.startActivity(ActivityManagerNative.java:1204)
at android.app.Instrumentation.execStartActivity(Instrumentation.java:1373)
at android.app.Activity.startActivityForResult(Activity.java:2749)
at android.app.Activity.startActivity(Activity.java:2855)
at ru.ivanovpv.android.storage.BulkContact.doContextItemSelected(BulkContact.java:105)
at ru.ivanovpv.android.cellmessenger.ContactsActivity.onContextItemSelected(ContactsActivity.java:188)
at android.app.Activity.onMenuItemSelected(Activity.java:2174)
at com.android.internal.policy.impl.PhoneWindow$ContextMenuCallback.onMenuItemSelected(PhoneWindow.java:2731)
at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:139)
at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:855)
at com.android.internal.view.menu.MenuDialogHelper.onClick(MenuDialogHelper.java:129)
at com.android.internal.app.AlertController$AlertParams$3.onItemClick(AlertController.java:884)
at android.widget.AdapterView.performItemClick(AdapterView.java:284)
at android.widget.ListView.performItemClick(ListView.java:3285)
at android.widget.AbsListView$PerformClick.run(AbsListView.java:1640)
at android.os.Handler.handleCallback(Handler.java:587)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:123)
at android.app.ActivityThread.main(ActivityThread.java:4363)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.io.NotSerializableException: ru.ivanovpv.android.storage.MyField$1
at java.io.ObjectOutputStream.writeNewObject(ObjectOutputStream.java:1547)
at java.io.ObjectOutputStream.writeObjectInternal(ObjectOutputStream.java:1854)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:1696)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:1660)
at java.io.ObjectOutputStream.writeFieldValues(ObjectOutputStream.java:1153)
at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:420)
at java.io.ObjectOutputStream.writeHierarchy(ObjectOutputStream.java:1251)
at java.io.ObjectOutputStream.writeNewObject(ObjectOutputStream.java:1587)
at java.io.ObjectOutputStream.writeObjectInternal(ObjectOutputStream.java:1854)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:1696)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:1660)
at android.os.Parcel.writeSerializable(Parcel.java:1126)
... 31 more

Can't really understand what's here is unserializable?

回答1:

Everything is pretty simple: "CREATOR" in the Parcelable implementation should be the "public static final" field - not just "public".

By leaving the "CREATOR" field just "public" you're making it a member of the MyField class. And as "CREATOR" is not "Serializable" - so you're getting a crash while system attempts to serialize all members of the MyField class.

回答2:

I think the problem is you are mixing Serializable with Parcelable. No need to mix them both, Parcelable is Google's personal implementation of Serializable. Don't need to do it, it mixes thing up. For example, if you are creating a new MyField(), why are you casting in the next line of code. Try to clean up the code, focusing on "the Android way" to do it. Check the examples on the documentation.

来源：https://stackoverflow.com/questions/6035381/serializable-parcelable-issue-runtimeexception-parcelable-encountered-ioexcept