FULL PRODUCT VERSION :
Java(TM) SE Runtime Environment (build 1.8.0_60-b27)
Java HotSpot(TM) 64-Bit Server VM (build 25.60-b23, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Darwin paul.internal 15.0.0 Darwin Kernel Version 15.0.0: Sat Sep 19 15:53:46 PDT 2015; root:xnu-3247.10.11~1/RELEASE_X86_64 x86_64

A DESCRIPTION OF THE PROBLEM :
The serialisation methods have not been updated to handle default methods yet.

It is not possible to define the serialisation methods such as readResolve() in an interface (as a default method).

A workaround is to define it in the class as well. E.g.:

@Override
 public Object readResolve()
 {
     return DefaultInstancePattern.super.readResolve();
 }

but that is what we are trying to avoid having to do by putting it in an interface.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
(1) Define a readResolve() method as default in an interface and implement that interface in a class.
(2) Serialise/deserialize the class and the readResolve() method will never be called.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Expected default readResolve() from the interface to be called when deserializing a class implementing the interface.
ACTUAL -
The default readResolve() from the interface was not called when deserializing a class implementing the interface.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
public interface InstancePattern extends Serializable {
    default Object readResolve() {
       return ReflectionUtils.getStaticInstance(this);
    }
}

public HelperClass implments InstancePattern {
    int i = 666;

   public void main(String[] args) {
     serializeAndDeserialize(new HelperClass());
   }

   private Serializable serializeAndDeserialize(Serializable object)
    {
        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        ObjectOutputStream objectOutputStream;
        
        try
        {
            objectOutputStream = new ObjectOutputStream(bytes);
            objectOutputStream.writeObject(object);
            objectOutputStream.close();
            
            byte[] actualBytes = bytes.toByteArray();
            ByteArrayInputStream byteStream = new ByteArrayInputStream(actualBytes);
            
            ObjectInputStream objectInputStream = new ObjectInputStream(byteStream);
            return (Serializable) objectInputStream.readObject();
        }
        catch (IOException | ClassNotFoundException ex)
        {
            throw new AssertionError("Something exceptional", ex);
        }
    }
}


---------- END SOURCE ----------