Package com.esotericsoftware.kryo.serializers

Class VersionFieldSerializer<T>

java.lang.Object

com.esotericsoftware.kryo.Serializer<T>

com.esotericsoftware.kryo.serializers.FieldSerializer<T>

com.esotericsoftware.kryo.serializers.VersionFieldSerializer<T>

public class VersionFieldSerializer<T>
extends FieldSerializer<T>

Serializes objects using direct field assignment, providing backward compatibility with minimal overhead. This means fields can be added without invalidating previously serialized bytes. Removing, renaming, or changing the type of a field is not supported.

When a field is added, it must have the VersionFieldSerializer.Since annotation to indicate the version it was added in order to be compatible with previously serialized bytes. The annotation value must never change.

Compared to FieldSerializer, VersionFieldSerializer writes a single additional varint and requires annotations for added fields, but provides backward compatibility so fields can be added. TaggedFieldSerializer provides more flexibility for classes to evolve in exchange for a slightly larger serialized size.

Author:

Nathan Sweet

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	VersionFieldSerializer.Since	Incremental modification of serialized objects must add VersionFieldSerializer.Since for new fields.
static class	VersionFieldSerializer.VersionFieldSerializerConfig	Configuration for VersionFieldSerializer instances.

Nested classes/interfaces inherited from class com.esotericsoftware.kryo.serializers.FieldSerializer

FieldSerializer.Bind, FieldSerializer.CachedField, FieldSerializer.FieldSerializerConfig, FieldSerializer.NotNull, FieldSerializer.Optional

Constructor Summary

Constructors

Constructor	Description
VersionFieldSerializer(Kryo kryo, Class type)
VersionFieldSerializer(Kryo kryo, Class type, VersionFieldSerializer.VersionFieldSerializerConfig config)

Method Summary

Modifier and Type	Method	Description
VersionFieldSerializer.VersionFieldSerializerConfig	getVersionFieldSerializerConfig()
protected void	initializeCachedFields()	Called when FieldSerializer.getFields() and FieldSerializer.getCopyFields() have been repopulated.
T	read(Kryo kryo, Input input, Class<? extends T> type)	Reads bytes and returns a new object of the specified concrete type.
void	removeField(FieldSerializer.CachedField field)	Removes a field so that it won't be serialized.
void	removeField(String fieldName)	Removes a field so that it won't be serialized.
void	write(Kryo kryo, Output output, T object)	Writes the bytes for the object to the output.

Methods inherited from class com.esotericsoftware.kryo.serializers.FieldSerializer

copy, create, createCopy, getCopyFields, getField, getFields, getFieldSerializerConfig, getKryo, getType, log, popTypeVariables, pushTypeVariables, updateFields

Methods inherited from class com.esotericsoftware.kryo.Serializer

getAcceptsNull, isImmutable, setAcceptsNull, setImmutable

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

VersionFieldSerializer

public VersionFieldSerializer(Kryo kryo,
                              Class type)

VersionFieldSerializer

public VersionFieldSerializer(Kryo kryo,
                              Class type,
                              VersionFieldSerializer.VersionFieldSerializerConfig config)

Method Detail

initializeCachedFields

protected void initializeCachedFields()

Description copied from class: FieldSerializer

Called when FieldSerializer.getFields() and FieldSerializer.getCopyFields() have been repopulated. Subclasses can override this method to configure or remove cached fields.

Overrides:

initializeCachedFields in class FieldSerializer<T>

removeField

public void removeField(String fieldName)

Description copied from class: FieldSerializer

Removes a field so that it won't be serialized.

Overrides:

removeField in class FieldSerializer<T>

removeField

public void removeField(FieldSerializer.CachedField field)

Description copied from class: FieldSerializer

Removes a field so that it won't be serialized.

Overrides:

removeField in class FieldSerializer<T>

write

public void write(Kryo kryo,
                  Output output,
                  T object)

Description copied from class: Serializer

Writes the bytes for the object to the output.

This method should not be called directly, instead this serializer can be passed to Kryo write methods that accept a serialier.

Overrides:

write in class FieldSerializer<T>

object - May be null if Serializer.getAcceptsNull() is true.

read

public T read(Kryo kryo,
              Input input,
              Class<? extends T> type)

Description copied from class: Serializer

Reads bytes and returns a new object of the specified concrete type.

Before Kryo can be used to read child objects, Kryo.reference(Object) must be called with the parent object to ensure it can be referenced by the child objects. Any serializer that uses Kryo to read a child object may need to be reentrant.

This method should not be called directly, instead this serializer can be passed to Kryo read methods that accept a serialier.

Overrides:

read in class FieldSerializer<T>

Returns:

May be null if Serializer.getAcceptsNull() is true.

getVersionFieldSerializerConfig

public VersionFieldSerializer.VersionFieldSerializerConfig getVersionFieldSerializerConfig()