Package com.esotericsoftware.kryo.serializers

Class MapSerializer<T extends Map>

java.lang.Object

com.esotericsoftware.kryo.Serializer<T>

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

Direct Known Subclasses:

DefaultSerializers.ConcurrentSkipListMapSerializer, DefaultSerializers.TreeMapSerializer, EnumMapSerializer, ImmutableCollectionsSerializers.JdkImmutableMapSerializer

public class MapSerializer<T extends Map>
extends Serializer<T>

Serializes objects that implement the Map interface.

With the default constructor, a map requires a 1-3 byte header and an extra 4 bytes is written for each key/value pair.

Author:

Nathan Sweet

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	MapSerializer.BindMap	Annotates a Map field with MapSerializer settings for FieldSerializer.

Constructor Summary

Constructors

Constructor	Description
MapSerializer()

Method Summary

Modifier and Type	Method	Description
T	copy(Kryo kryo, T original)	Returns a copy of the specified object.
protected T	create(Kryo kryo, Input input, Class<? extends T> type, int size)	Used by read(Kryo, Input, Class) to create the new object.
protected T	createCopy(Kryo kryo, T original)
Class	getKeyClass()
Serializer	getKeySerializer()
Class	getValueClass()
Serializer	getValueSerializer()
T	read(Kryo kryo, Input input, Class<? extends T> type)	Reads bytes and returns a new object of the specified concrete type.
void	setKeyClass(Class keyClass)	The concrete class of the keys for this map, or null if it is not known.
void	setKeyClass(Class keyClass, Serializer keySerializer)	Sets both setKeyClass(Class) and setKeySerializer(Serializer).
void	setKeysCanBeNull(boolean keysCanBeNull)
void	setKeySerializer(Serializer keySerializer)	The serializer to be used for the keys in this map, or null to use the serializer registered with Kryo for the type.
void	setValueClass(Class valueClass)	The concrete class of the values for this map, or null if it is not known.
void	setValueClass(Class valueClass, Serializer valueSerializer)	Sets both setValueClass(Class) and setValueSerializer(Serializer).
void	setValuesCanBeNull(boolean valuesCanBeNull)
void	setValueSerializer(Serializer valueSerializer)	The serializer to be used for this field, or null to use the serializer registered with Kryo for the type.
void	write(Kryo kryo, Output output, T map)	Writes the bytes for the object to the output.
protected void	writeHeader(Kryo kryo, Output output, T map)	Can be overidden to write data needed for create(Kryo, Input, Class, int).

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

MapSerializer

public MapSerializer()

Method Detail

setKeysCanBeNull

public void setKeysCanBeNull(boolean keysCanBeNull)

Parameters:

keysCanBeNull - False if all keys are not null. This saves 1 byte per key if keyClass is set. True if it is not known (default).

setKeyClass

public void setKeyClass(Class keyClass)

The concrete class of the keys for this map, or null if it is not known. This saves 1-2 bytes. Only set to a non-null value if the keys for this map are known to be of the specified type (or null).

getKeyClass

public Class getKeyClass()

setKeyClass

public void setKeyClass(Class keyClass,
                        Serializer keySerializer)

Sets both setKeyClass(Class) and setKeySerializer(Serializer).

setKeySerializer

public void setKeySerializer(Serializer keySerializer)

The serializer to be used for the keys in this map, or null to use the serializer registered with Kryo for the type. Default is null.

getKeySerializer

public Serializer getKeySerializer()

setValueClass

public void setValueClass(Class valueClass)

The concrete class of the values for this map, or null if it is not known. This saves 1-2 bytes. Only set to a non-null value if the values for this map are known to be of the specified type (or null).

getValueClass

public Class getValueClass()

setValueClass

public void setValueClass(Class valueClass,
                          Serializer valueSerializer)

Sets both setValueClass(Class) and setValueSerializer(Serializer).

setValueSerializer

public void setValueSerializer(Serializer valueSerializer)

The serializer to be used for this field, or null to use the serializer registered with Kryo for the type. Default is null.

getValueSerializer

public Serializer getValueSerializer()

setValuesCanBeNull

public void setValuesCanBeNull(boolean valuesCanBeNull)

Parameters:

valuesCanBeNull - True if values are not null. This saves 1 byte per value if keyClass is set. False if it is not known (default).

write

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

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.

Specified by:

write in class Serializer<T extends Map>

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

writeHeader

protected void writeHeader(Kryo kryo,
                           Output output,
                           T map)

Can be overidden to write data needed for create(Kryo, Input, Class, int). The default implementation does nothing.

create

protected T create(Kryo kryo,
                   Input input,
                   Class<? extends T> type,
                   int size)

Used by read(Kryo, Input, Class) to create the new object. This can be overridden to customize object creation, eg to call a constructor with arguments. The default implementation uses Kryo.newInstance(Class) with a special case for HashMap.

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.

Specified by:

read in class Serializer<T extends Map>

Returns:

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

createCopy

protected T createCopy(Kryo kryo,
                       T original)

copy

public T copy(Kryo kryo,
              T original)

Description copied from class: Serializer

Returns a copy of the specified object. The default implementation returns the original if Serializer.isImmutable() is true, else throws KryoException. Subclasses can optionall override this method to support Kryo.copy(Object).

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

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

Overrides:

copy in class Serializer<T extends Map>