org.axonframework.eventhandling

Class GenericEventMessage<T>

java.lang.Object

org.axonframework.messaging.MessageDecorator<T>

org.axonframework.eventhandling.GenericEventMessage<T>

Type Parameters:

T - The type of payload contained in this Message

All Implemented Interfaces:

Serializable, EventMessage<T>, Message<T>

Direct Known Subclasses:

GenericDeadlineMessage, GenericDomainEventMessage, GenericTrackedEventMessage

public class GenericEventMessage<T>
extends MessageDecorator<T>
implements EventMessage<T>

Generic implementation of the EventMessage interface.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static Clock	clock Clock instance used to set the time on new events.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	GenericEventMessage(Message<T> delegate, Instant timestamp) Initializes a GenericEventMessage with given message as delegate and given timestamp.
	GenericEventMessage(Message<T> delegate, Supplier<Instant> timestampSupplier) Constructor to reconstruct an EventMessage using existing data.
	GenericEventMessage(String identifier, T payload, Map<String,?> metaData, Instant timestamp) Constructor to reconstruct an EventMessage using existing data.
	GenericEventMessage(T payload) Creates a GenericEventMessage with given payload, and an empty MetaData.
	GenericEventMessage(T payload, Map<String,?> metaData) Creates a GenericEventMessage with given payload and given metaData.

Method Summary

Modifier and Type	Method and Description
GenericEventMessage<T>	andMetaData(Map<String,?> metaData) Returns a copy of this EventMessage with it MetaData merged with the given metaData.
static <T> EventMessage<T>	asEventMessage(Object event) Returns the given event as an EventMessage.
protected void	describeTo(StringBuilder stringBuilder) Describe the message specific properties to the given stringBuilder.
protected String	describeType() Describe the type of message, used in MessageDecorator.toString().
Instant	getTimestamp() Returns the timestamp of this event.
GenericEventMessage<T>	withMetaData(Map<String,?> metaData) Returns a copy of this EventMessage with the given metaData.

Methods inherited from class org.axonframework.messaging.MessageDecorator

getDelegate, getIdentifier, getMetaData, getPayload, getPayloadType, serializeMetaData, serializePayload, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.axonframework.eventhandling.EventMessage

getIdentifier

Methods inherited from interface org.axonframework.messaging.Message

getMetaData, getPayload, getPayloadType, serializeMetaData, serializePayload

Field Detail

clock

public static Clock clock

Clock instance used to set the time on new events. To fix the time while testing set this value to a constant value.

Constructor Detail

GenericEventMessage

public GenericEventMessage(T payload)

Creates a GenericEventMessage with given payload, and an empty MetaData.

Parameters:

payload - The payload for the message

See Also:

asEventMessage(Object)

GenericEventMessage

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

Creates a GenericEventMessage with given payload and given metaData.

Parameters:

payload - The payload of the EventMessage

metaData - The MetaData for the EventMessage

See Also:

asEventMessage(Object)

GenericEventMessage

public GenericEventMessage(String identifier,
                           T payload,
                           Map<String,?> metaData,
                           Instant timestamp)

Constructor to reconstruct an EventMessage using existing data.

Parameters:

identifier - The identifier of the Message

timestamp - The timestamp of the Message creation

payload - The payload of the message

metaData - The meta data of the message

GenericEventMessage

public GenericEventMessage(Message<T> delegate,
                           Supplier<Instant> timestampSupplier)

Constructor to reconstruct an EventMessage using existing data. The timestamp of the event is supplied lazily to prevent unnecessary deserialization of the timestamp.

Parameters:

delegate - The message containing payload, identifier and metadata

timestampSupplier - Supplier for the timestamp of the Message creation

GenericEventMessage

protected GenericEventMessage(Message<T> delegate,
                              Instant timestamp)

Initializes a GenericEventMessage with given message as delegate and given timestamp. The given message will be used supply the payload, metadata and identifier of the resulting event message.

Parameters:

delegate - the message that will be used used as delegate

timestamp - the timestamp of the resulting event message

Method Detail

asEventMessage

public static <T> EventMessage<T> asEventMessage(Object event)

Returns the given event as an EventMessage. If event already implements EventMessage, it is returned as-is. If it is a Message, a new EventMessage will be created using the payload and meta data of the given message. Otherwise, the given event is wrapped into a GenericEventMessage as its payload.

Type Parameters:

T - The generic type of the expected payload of the resulting object

Parameters:

event - the event to wrap as EventMessage

Returns:

an EventMessage containing given event as payload, or event if it already implements EventMessage.

getTimestamp

public Instant getTimestamp()

Description copied from interface: EventMessage

Returns the timestamp of this event. The timestamp is set to the date and time the event was reported.

Specified by:

getTimestamp in interface EventMessage<T>

Returns:

the timestamp of this event.

withMetaData

public GenericEventMessage<T> withMetaData(Map<String,?> metaData)

Description copied from interface: EventMessage

Returns a copy of this EventMessage with the given metaData. The payload, Timestamp and Identifier remain unchanged.

Specified by:

withMetaData in interface EventMessage<T>

Specified by:

withMetaData in interface Message<T>

Parameters:

metaData - The new MetaData for the Message

Returns:

a copy of this message with the given MetaData

andMetaData

public GenericEventMessage<T> andMetaData(Map<String,?> metaData)

Description copied from interface: EventMessage

Returns a copy of this EventMessage with it MetaData merged with the given metaData. The payload, Timestamp and Identifier remain unchanged.

Specified by:

andMetaData in interface EventMessage<T>

Specified by:

andMetaData in interface Message<T>

Parameters:

metaData - The MetaData to merge with

Returns:

a copy of this message with the given MetaData

describeTo

protected void describeTo(StringBuilder stringBuilder)

Description copied from class: MessageDecorator

Describe the message specific properties to the given stringBuilder. Subclasses should override this method, calling the super method and appending their own properties to the end (or beginning).

As convention, String values should be enclosed in single quotes, Objects in curly brackets and numeric values may be appended without enclosing. All properties should be preceded by a comma when appending, or finish with a comma when prefixing values.

Overrides:

describeTo in class MessageDecorator<T>

Parameters:

stringBuilder - the builder to append data to

describeType

protected String describeType()

Description copied from class: MessageDecorator

Describe the type of message, used in MessageDecorator.toString().

Defaults to the simple class name of the actual instance.

Overrides:

describeType in class MessageDecorator<T>

Returns:

the type of message