Problem unmarshalling parcelables

user_76835 0
Viewed 47759

I've got a few classes that implement Parcelable and some of these classes contain each other as properties. I'm marshalling the classes into a Parcel to pass them between activities. Marshalling them TO the Parcel works fine, but when I try to unmarshall them I get the following error:

...
AndroidRuntime  E  Caused by: android.os.BadParcelableException: ClassNotFoundException when unmarshalling: schemas.Arrivals.LocationType
AndroidRuntime  E   at android.os.Parcel.readParcelable(Parcel.java:1822)
AndroidRuntime  E   at schemas.Arrivals.LayoverType.<init>(LayoverType.java:121)
AndroidRuntime  E   at schemas.Arrivals.LayoverType.<init>(LayoverType.java:120)
AndroidRuntime  E   at schemas.Arrivals.LayoverType$1.createFromParcel(LayoverType.java:112)
AndroidRuntime  E   at schemas.Arrivals.LayoverType$1.createFromParcel(LayoverType.java:1)
AndroidRuntime  E   at android.os.Parcel.readTypedList(Parcel.java:1509)
AndroidRuntime  E   at schemas.Arrivals.BlockPositionType.<init>(BlockPositionType.java:244)
AndroidRuntime  E   at schemas.Arrivals.BlockPositionType.<init>(BlockPositionType.java:242)
AndroidRuntime  E   at schemas.Arrivals.BlockPositionType$1.createFromParcel(BlockPositionType.java:234)
AndroidRuntime  E   at schemas.Arrivals.BlockPositionType$1.createFromParcel(BlockPositionType.java:1)
...

The LayoverType class (where it's failing):

public class LayoverType implements Parcelable {    
    protected LocationType location;
    protected long start;
    protected long end;

    public LayoverType() {}

    public LocationType getLocation() {
        return location;
    }

    public void setLocation(LocationType value) {
        this.location = value;
    }

    public long getStart() {
        return start;
    }

    public void setStart(long value) {
        this.start = value;
    }

    public long getEnd() {
        return end;
    }

    public void setEnd(long value) {
        this.end = value;
    }


    // **********************************************
    //  for implementing Parcelable
    // **********************************************

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeParcelable(location, flags);
        dest.writeLong(start);
        dest.writeLong(end  );
    }

    public static final Parcelable.Creator<LayoverType> CREATOR = new Parcelable.Creator<LayoverType>() {
        public LayoverType createFromParcel(Parcel in) {
            return new LayoverType(in);
        }

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

    private LayoverType(Parcel dest) {
        location = (LocationType) dest.readParcelable(null);    // it's failing here
        start = dest.readLong();
        end   = dest.readLong();
    }
}

Here's the LocationType class:

public class LocationType implements Parcelable {
    protected int locid;
    protected String desc;
    protected String dir;
    protected double lat;
    protected double lng;

    public LocationType() {}

    public int getLocid() {
        return locid;
    }

    public void setLocid(int value) {
        this.locid = value;
    }

    public String getDesc() {
        return desc;
    }

    public void setDesc(String value) {
        this.desc = value;
    }

    public String getDir() {
        return dir;
    }

    public void setDir(String value) {
        this.dir = value;
    }

    public double getLat() {
        return lat;
    }

    public void setLat(double value) {
        this.lat = value;
    }

    public double getLng() {
        return lng;
    }

    public void setLng(double value) {
        this.lng = value;
    }

    // **********************************************
    //  for implementing Parcelable
    // **********************************************


    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeInt   (locid);
        dest.writeString(desc );
        dest.writeString(dir  );
        dest.writeDouble(lat  );
        dest.writeDouble(lng  );
    }

    public static final Parcelable.Creator<LocationType> CREATOR = new Parcelable.Creator<LocationType>() {
        public LocationType createFromParcel(Parcel in) {
            return new LocationType(in);
        }

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

    private LocationType(Parcel dest) {
        locid = dest.readInt   ();
        desc  = dest.readString();
        dir   = dest.readString();
        lat   = dest.readDouble();
        lng   = dest.readDouble();
    }
}

Update 2: As far as I can tell it's failing at the following bit of code (from Parcel's source):

Class c = loader == null ? Class.forName(name) : Class.forName(name, true, loader);

Why is it not able to find the class? It both exists and implements Parcelable.

parcelable marshalling android java
10 Answers

Because this was not answered in "answer" but in comment I will post an answer: As @Max-Gontar pointed you should use LocationType.class.getClassLoader() to get the correct ClassLoader and get rid of ClassNotFound exception, i.e.:

in.readParceleable(LocationType.class.getClassLoader());

user_4251830

I found the problem was I was not passing my applications ClassLoader to the unmarshalling function:

in.readParceleable(getContext().getClassLoader());

Rather than:

in.readParceleable(null);

OR

in.readParceleable(MyClass.class.getClassLoader());
mxcl_64440

I am not very familiar with Parcelable but if it's anything like Serialization each call to write an object that implements the interface will cause a recursive call to writeToParcel(). Therefore, if something along the call stack fails or writes a null value the class that initiated the call may not be constructed correctly.

Try: Trace the writeToParcel() call stack through all the classes starting at the first call to writeToParcel() and verify that all the values are getting sent correctly.

user_757800

Instead of using writeParcelable and readParcelable use writeToParcel and createFromParcel directly. So the better code is:

@Override
public void writeToParcel(Parcel dest, int flags) {
    location.writeToParcel(dest, flags);
    dest.writeLong(start);
    dest.writeLong(end  );
}

public static final Parcelable.Creator<LayoverType> CREATOR = new Parcelable.Creator<LayoverType>() {
    public LayoverType createFromParcel(Parcel in) {
        return new LayoverType(in);
    }

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

private LayoverType(Parcel dest) {
    location = LocationType.CREATOR.createFromParcel(dest);
    start = dest.readLong();
    end   = dest.readLong();
}
user_5545240

If you have an Object with a property of type of List objects you should pass the class loader when you read the property for example:

public class Mall implements Parcelable {

    public List<Outstanding> getOutstanding() {
        return outstanding;
    }

    public void setOutstanding(List<Outstanding> outstanding) {
        this.outstanding = outstanding;
    }        

    protected Mall(Parcel in) {
        outstanding = new ArrayList<Outstanding>();
        //this is the key, pass the class loader
        in.readList(outstanding, Outstanding.class.getClassLoader());
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeList(outstanding);
    }

    public static final Parcelable.Creator<Mall> CREATOR = new Parcelable.Creator<Mall>() {
        public Mall createFromParcel(Parcel in) {
            return new Mall(in);
        }

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

Note: Is important that the class Outstanding implements the Parceable interface.

user_6465530

I got this exception because I was missing a constructor. The same must be done for all classes that implement Parcelable:

// add new constructor
@RequiresApi(Build.VERSION_CODES.N)
private LocationType(Parcel dest, ClassLoader loader) {
    super(dest, loader);
    locid = dest.readInt();
    desc  = dest.readString();
    dir   = dest.readString();
    lat   = dest.readDouble();
    lng   = dest.readDouble();
}

public static final Creator<LayoverType> CREATOR = new ClassLoaderCreator<LayoverType>() {

    // add createFromParcel method with ClassLoader
    @Override
    public LayoverType createFromParcel(Parcel in, ClassLoader loader)
    {
        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.N ? new LayoverType(in, loader) : new LayoverType(in);
    }

    public LayoverType createFromParcel(Parcel in) {
        // call other createFromParcel method.    
        return createFromParcel(in, null);
    }

    public LayoverType[] newArray(int size) {
        return new LayoverType[size];
    }
};
user_22127700
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