Class ExternalizableSerializer

java.lang.Object

com.esotericsoftware.kryo.Serializer

com.esotericsoftware.kryo.serializers.ExternalizableSerializer

public class ExternalizableSerializer
extends Serializer

Writes using the objects externalizable interface if it can reliably do so. Typically, a object can be efficiently written with Kryo and Java's externalizable interface. However, there may be behavior problems if the class uses either the 'readResolve' or 'writeReplace' methods. We will fall back onto the standard JavaSerializer if we detect either of these methods.

Note that this class does not specialize the type on Externalizable. That is because if we fall back on the JavaSerializer it may have an readResolve method that returns an object of a different type.

Field Summary

Fields

Modifier and Type	Field	Description
private ObjectMap<Class, JavaSerializer>	javaSerializerByType
private KryoObjectInput	objectInput
private KryoObjectOutput	objectOutput

Constructor Summary

Constructors

Constructor	Description
ExternalizableSerializer()

Method Summary

Modifier and Type	Method	Description
private JavaSerializer	getCachedSerializer(Class type)
private JavaSerializer	getJavaSerializerIfRequired(Class type)	Determines if this class requires the fall-back JavaSerializer.
private ObjectInput	getObjectInput(Kryo kryo, Input input)
private ObjectOutput	getObjectOutput(Kryo kryo, Output output)
private static boolean	hasInheritableReplaceMethod(Class type, String methodName)
private boolean	isJavaSerializerRequired(Class type)
Object	read(Kryo kryo, Input input, Class type)	Reads bytes and returns a new object of the specified concrete type.
private Object	readExternal(Kryo kryo, Input input, Class type)
void	write(Kryo kryo, Output output, Object object)	Writes the bytes for the object to the output.
private void	writeExternal(Kryo kryo, Output output, Object object)

Methods inherited from class Serializer

copy, getAcceptsNull, isImmutable, setAcceptsNull, setGenerics, setImmutable

Methods inherited from class Object

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

Field Details

javaSerializerByType

private ObjectMap<Class, JavaSerializer> javaSerializerByType

objectInput

private KryoObjectInput objectInput

objectOutput

private KryoObjectOutput objectOutput

Constructor Details

ExternalizableSerializer

public ExternalizableSerializer()

Method Details

write

public void write(Kryo kryo,
 Output output,
 Object 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.

Specified by:

write in class Serializer

Parameters:

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

read

public Object read(Kryo kryo,
 Input input,
 Class 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

Returns:

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

writeExternal

private void writeExternal(Kryo kryo,
 Output output,
 Object object)

readExternal

private Object readExternal(Kryo kryo,
 Input input,
 Class type)

getObjectOutput

private ObjectOutput getObjectOutput(Kryo kryo,
 Output output)

getObjectInput

private ObjectInput getObjectInput(Kryo kryo,
 Input input)

getJavaSerializerIfRequired

private JavaSerializer getJavaSerializerIfRequired(Class type)

Determines if this class requires the fall-back JavaSerializer. If the class does not require any specialized Java serialization features then null will be returned.

Parameters:

type - the type we wish to externalize

Returns:

a JavaSerializer if the type requires more than simple externalization.

getCachedSerializer

private JavaSerializer getCachedSerializer(Class type)

isJavaSerializerRequired

private boolean isJavaSerializerRequired(Class type)

hasInheritableReplaceMethod

private static boolean hasInheritableReplaceMethod(Class type,
 String methodName)