Package com.oracle.coherence.io.json.genson.reflect

Interface UnknownPropertyHandler

All Known Implementing Classes:

EvolvableHandler

public interface UnknownPropertyHandler

An interface that defines callbacks that will be called when an unknown properties are encountered during deserialization, as well as to check if there are any unknown properties that should be written out during serialization.

The main purpose of this interface is to support schema evolution of objects that use JSON as a long term storage format, without loss of unknown properties across clients and severs using different versions of Java classes.

Author:

Aleks Seovic 2018.05.09

Method Summary

Modifier and Type	Method	Description
<T> Consumer<T>	readUnknownProperty(String propName, ObjectReader reader, Context ctx)	Called whenever a property is encountered in a JSON document that doesn't have a corresponding PropertyMutator.
default <T> void	writeUnknownProperties(T bean, ObjectWriter writer, Context ctx)	Write unknown properties encountered during deserialization.

Method Detail

readUnknownProperty

<T> Consumer<T> readUnknownProperty(String propName,
                                    ObjectReader reader,
                                    Context ctx)

Called whenever a property is encountered in a JSON document that doesn't have a corresponding PropertyMutator.

Typically, the implementation of this interface concerned with schema evolution will handle this event by storing property value somewhere so it can be written later by the writeUnknownProperties(T, com.oracle.coherence.io.json.genson.stream.ObjectWriter, com.oracle.coherence.io.json.genson.Context) method.

Parameters:

propName - the name of the unknown property

reader - the ObjectReader to read property value from

ctx - deserialization context

Returns:

the Consumer that will be called with the target bean, once the target bean is known

writeUnknownProperties

default <T> void writeUnknownProperties(T bean,
                                        ObjectWriter writer,
                                        Context ctx)

Write unknown properties encountered during deserialization.

This method can be optionally implemented by UnknownPropertyHandlers that want to write unknown properties during serialization. The default implementation is a no-op.

Parameters:

bean - the object we are serializing into JSON

writer - the ObjectReader to read property value from

ctx - serialization context