Serializer

EclipseStore’s serialization engine, which is used by the storage, can be used standalone as well. It is usable as as replacement for the default Java serialization to convert objects to a binary format and vice versa. This API is part of the persistence-binary module:

Prerequisites

pom.xml
<dependencies>
	<dependency>
		<groupId>org.eclipse.serializer</groupId>
		<artifactId>serializer</artifactId>
		<version>1.2.0</version>
	</dependency>
</dependencies>

Usage

You can use any medium type, but for most purposes the byte array version should be sufficient, to transfer the serialized form over the transport layer of your choice. Simply create a serializer instance, optionally based on a foundation, and call the serialize and deserialize methods.

final SerializerFoundation<?> foundation = SerializerFoundation.New()
	.registerEntityTypes(Customer.class);
final Serializer<byte[]> serializer = Serializer.Bytes(foundation);
byte[] data = serializer.serialize(customer);
Customer restored = serializer.deserialize(data);

Type handling

The serializer uses the EclipseStore’s type handling system. This includes registration of new types on demand during serialization and legacy type mapping when deserializing. The SerializerFoundation provides an API like the MicroStream storage to configure the type handling behavior.

The default Serializer implementation does not include type information in the serialized output! If you want to deserialize that with another serializer instance you must register all classes using the SerializerFoundation before you create the serializer or use a TypedSerializer!

TypedSerializer

The TypedSerializer implementation includes type information into the serialized output. By default the complete set of type information is included in all serialized output.

final Serializer<byte[]> serializer = TypedSerializer.Bytes(foundation);
byte[] data = serializer.serialize(customer);
Customer restored = serializer.deserialize(data);

Configuring the included type information

To reduce the serialized data it is possible to configure the included type information by suppling a SerializerTypeInfoStrategyCreator to the SerializerFoundation.

final SerializerFoundation<?> foundation = SerializerFoundation.New()
	.setSerializerTypeInfoStrategyCreator(
		new SerializerTypeInfoStrategyCreator.IncrementalDiff(false));
return TypedSerializer.Bytes(foundation);

Available options are:

Property Description

TypeDictionary

Includes type information for all types currently known to the serializer including those registered during the setup.

Diff

Includes type information for all types currently known to the serializer including those registered during the setup.

IncrementalDiff

Includes only type information for types added to the serializers type registry in the current serialization. Types that are registered during the serializers setup are never included.

The includeTypeInfoOnce parameter:

All three serializer type handling strategies allow to specify that the type information gets included only once if it has not changed by setting the parameter includeTypeInfoOnce = true. If so, the type information is only included if there where new types registered during the current serialization.