org.axonframework.messaging

Class GenericMessage<T>

java.lang.Object

org.axonframework.messaging.AbstractMessage<T>

org.axonframework.messaging.GenericMessage<T>

All Implemented Interfaces:

Serializable, Message<T>

public class GenericMessage<T>
extends AbstractMessage<T>

Generic implementation of a Message that contains the payload and metadata as unserialized values.

If a GenericMessage is created while a UnitOfWork is active it copies over the correlation data of the UnitOfWork to the created message.

Since:

2.0

Author:

Allard Buijze

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
GenericMessage(Class<T> declaredPayloadType, T payload, Map<String,?> metaData) Constructs a Message for the given payload and meta data.
GenericMessage(String identifier, Class<T> declaredPayloadType, T payload, Map<String,?> metaData) Constructor to reconstruct a Message using existing data.
GenericMessage(String identifier, T payload, Map<String,?> metaData) Constructor to reconstruct a Message using existing data.
GenericMessage(T payload) Constructs a Message for the given payload using the correlation data of the current Unit of Work, if present.
GenericMessage(T payload, Map<String,?> metaData) Constructs a Message for the given payload and meta data.

Method Summary

Modifier and Type	Method and Description
static Message<?>	asMessage(Object payloadOrMessage) Returns a Message representing the given payloadOrMessage, either by wrapping it or by returning it as-is.
MetaData	getMetaData() Returns the meta data for this event.
T	getPayload() Returns the payload of this Event.
Class<T>	getPayloadType() Returns the type of the payload.
<R> SerializedObject<R>	serializeMetaData(Serializer serializer, Class<R> expectedRepresentation) Serialize the meta data of this message to the expectedRepresentation using given serializer.
<R> SerializedObject<R>	serializePayload(Serializer serializer, Class<R> expectedRepresentation) Serialize the payload of this message to the expectedRepresentation using given serializer.
protected Message<T>	withMetaData(MetaData metaData) Returns a new message instance with the same payload and properties as this message but given metaData.

Methods inherited from class org.axonframework.messaging.AbstractMessage

andMetaData, getIdentifier, withMetaData

Methods inherited from class java.lang.Object

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

Constructor Detail

GenericMessage

public GenericMessage(T payload)

Constructs a Message for the given payload using the correlation data of the current Unit of Work, if present.

Parameters:

payload - The payload for the message

GenericMessage

public GenericMessage(T payload,
                      Map<String,?> metaData)

Constructs a Message for the given payload and meta data. The given metaData is merged with the MetaData from the correlation data of the current unit of work, if present. In case the payload == null, Void will be used as the payloadType.

Parameters:

payload - The payload for the message as a generic T

metaData - The meta data Map for the message

GenericMessage

public GenericMessage(Class<T> declaredPayloadType,
                      T payload,
                      Map<String,?> metaData)

Constructs a Message for the given payload and meta data. The given metaData is merged with the MetaData from the correlation data of the current unit of work, if present.

Parameters:

declaredPayloadType - The declared type of message payload

payload - The payload for the message

metaData - The meta data for the message

GenericMessage

public GenericMessage(String identifier,
                      T payload,
                      Map<String,?> metaData)

Constructor to reconstruct a Message using existing data. Note that no correlation data from a UnitOfWork is attached when using this constructor. If you're constructing a new Message, use GenericMessage(Object, Map) instead.

Parameters:

identifier - The identifier of the Message

payload - The payload of the message

metaData - The meta data of the message

Throws:

NullPointerException - when the given payload is null.

GenericMessage

public GenericMessage(String identifier,
                      Class<T> declaredPayloadType,
                      T payload,
                      Map<String,?> metaData)

Constructor to reconstruct a Message using existing data. Note that no correlation data from a UnitOfWork is attached when using this constructor. If you're constructing a new Message, use GenericMessage(Object, Map) instead

Parameters:

identifier - The identifier of the Message

declaredPayloadType - The declared type of message payload

payload - The payload for the message

metaData - The meta data for the message

Method Detail

asMessage

public static Message<?> asMessage(Object payloadOrMessage)

Returns a Message representing the given payloadOrMessage, either by wrapping it or by returning it as-is. If the given payloadOrMessage already implements Message, it is returned as-is, otherwise a Message is returned with the parameter as its payload.

Parameters:

payloadOrMessage - The payload to wrap or message to return

Returns:

a Message with the given payload or the message

getMetaData

public MetaData getMetaData()

Description copied from interface: Message

Returns the meta data for this event. This meta data is a collection of key-value pairs, where the key is a String, and the value is a serializable object.

Returns:

the meta data for this event

getPayload

public T getPayload()

Description copied from interface: Message

Returns the payload of this Event. The payload is the application-specific information.

Returns:

the payload of this Event

getPayloadType

public Class<T> getPayloadType()

Description copied from interface: Message

Returns the type of the payload.

Is semantically equal to getPayload().getClass(), but allows implementations to optimize by using lazy loading or deserialization.

Returns:

the type of payload.

withMetaData

protected Message<T> withMetaData(MetaData metaData)

Description copied from class: AbstractMessage

Returns a new message instance with the same payload and properties as this message but given metaData.

Specified by:

withMetaData in class AbstractMessage<T>

Parameters:

metaData - The metadata in the new message

Returns:

a copy of this instance with given metadata

serializePayload

public <R> SerializedObject<R> serializePayload(Serializer serializer,
                                                Class<R> expectedRepresentation)

Description copied from interface: Message

Serialize the payload of this message to the expectedRepresentation using given serializer. This method should return the same SerializedObject instance when invoked multiple times using the same serializer.

Type Parameters:

R - The type of the serialized data

Parameters:

serializer - The serializer to serialize payload with

expectedRepresentation - The type of data to serialize to

Returns:

a SerializedObject containing the serialized representation of the message's payload

serializeMetaData

public <R> SerializedObject<R> serializeMetaData(Serializer serializer,
                                                 Class<R> expectedRepresentation)

Description copied from interface: Message

Serialize the meta data of this message to the expectedRepresentation using given serializer. This method should return the same SerializedObject instance when invoked multiple times using the same serializer.

Type Parameters:

R - The type of the serialized data

Parameters:

serializer - The serializer to serialize meta data with

expectedRepresentation - The type of data to serialize to

Returns:

a SerializedObject containing the serialized representation of the message's meta data