Interface Message<T>
- Type Parameters:
T
- The type of the message payload.
public interface Message<T>
A message envelope.
A message contains a non-null
payload, an acknowledgement function and a set of metadata.
Metadata are indexed using the class name of the values.
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Field Summary
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Method Summary
Modifier and TypeMethodDescriptiondefault CompletionStage<Void>
ack()
Acknowledge this message.addMetadata
(Object metadata) Creates a new instance ofMessage
with the current metadata, plus the given one.default Supplier<CompletionStage<Void>>
getAck()
default Metadata
default <M> Optional<M>
getMetadata
(Class<? extends M> clazz) Retrieves the metadata associated with the given class.default Function<Throwable,
CompletionStage<Void>> getNack()
default CompletionStage<Void>
Acknowledge negatively this message.default CompletionStage<Void>
Acknowledge negatively this message.static <T> Message<T>
of
(T payload) Create a message with the given payload.static <T> Message<T>
Create a message with the given payload and metadata.static <T> Message<T>
Create a message with the given payload, metadata and ack function.static <T> Message<T>
of
(T payload, Iterable<Object> metadata, Supplier<CompletionStage<Void>> ack, Function<Throwable, CompletionStage<Void>> nack) Create a message with the given payload, metadata and ack and nack functions.static <T> Message<T>
of
(T payload, Supplier<CompletionStage<Void>> ack) Create a message with the given payload and ack function.static <T> Message<T>
of
(T payload, Supplier<CompletionStage<Void>> ack, Function<Throwable, CompletionStage<Void>> nack) Create a message with the given payload, ack and nack functions.static <T> Message<T>
Create a message with the given payload and metadata.static <T> Message<T>
of
(T payload, Metadata metadata, Supplier<CompletionStage<Void>> ack) Create a message with the given payload, metadata and ack function.static <T> Message<T>
of
(T payload, Metadata metadata, Supplier<CompletionStage<Void>> ack, Function<Throwable, CompletionStage<Void>> nack) Create a message with the given payload, metadata and ack and nack functions.default <C> C
Returns an object of the specified type to allow access to the connector-specificMessage
implementation, and other classes.withAck
(Supplier<CompletionStage<Void>> supplier) Creates a new instance ofMessage
with the given acknowledgement supplier.withMetadata
(Iterable<Object> metadata) Creates a new instance ofMessage
with the specified metadata.withMetadata
(Metadata metadata) Creates a new instance ofMessage
with the specified metadata.withNack
(Function<Throwable, CompletionStage<Void>> nack) Creates a new instance ofMessage
with the given negative-acknowledgement function.default <P> Message<P>
withPayload
(P payload) Creates a new instance ofMessage
with the specified payload.
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Field Details
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LOGGER
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Method Details
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of
Create a message with the given payload. No metadata are associated with the message, the acknowledgement and negative acknowledgement are immediate.- Type Parameters:
T
- The type of payload- Parameters:
payload
- The payload.- Returns:
- A message with the given payload, no metadata, and no-op ack and nack functions.
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of
Create a message with the given payload and metadata. The acknowledgement and negative-acknowledgement are immediate.- Type Parameters:
T
- The type of payload- Parameters:
payload
- The payload.metadata
- The metadata, ifnull
an empty set of metadata is used.- Returns:
- A message with the given payload, metadata and no-op ack and nack functions.
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of
Create a message with the given payload and metadata. The acknowledgement and negative-acknowledgement are immediate.- Type Parameters:
T
- The type of payload- Parameters:
payload
- The payload.metadata
- The metadata, must not benull
, must not containnull
values, can be empty- Returns:
- A message with the given payload, metadata and no-op ack and nack functions.
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of
Create a message with the given payload and ack function. No metadata are associated with the message. Negative-acknowledgement is immediate.- Type Parameters:
T
- the type of payload- Parameters:
payload
- The payload.ack
- The ack function, this will be invoked when the returned messagesack()
method is invoked.- Returns:
- A message with the given payload, no metadata and ack function.
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of
Create a message with the given payload, metadata and ack function. Negative-acknowledgement is immediate.- Type Parameters:
T
- the type of payload- Parameters:
payload
- The payload.metadata
- the metadata, ifnull
, empty metadata are used.ack
- The ack function, this will be invoked when the returned messagesack()
method is invoked.- Returns:
- A message with the given payload and ack function.
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of
Create a message with the given payload, metadata and ack function. Negative-acknowledgement is immediate.- Type Parameters:
T
- the type of payload- Parameters:
payload
- The payload.metadata
- the metadata, must not benull
, must not containnull
values.ack
- The ack function, this will be invoked when the returned messagesack()
method is invoked.- Returns:
- A message with the given payload and ack function.
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of
@Experimental("nack support is a SmallRye-only feature") static <T> Message<T> of(T payload, Supplier<CompletionStage<Void>> ack, Function<Throwable, CompletionStage<Void>> nack) Create a message with the given payload, ack and nack functions.- Type Parameters:
T
- the type of payload- Parameters:
payload
- The payload.ack
- The ack function, this will be invoked when the returned messagesack()
method is invoked.nack
- The negative-ack function, this will be invoked when the returned messagesnack(Throwable)
method is invoked.- Returns:
- A message with the given payload, metadata, ack and nack functions.
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of
@Experimental("nack support is a SmallRye-only feature") static <T> Message<T> of(T payload, Iterable<Object> metadata, Supplier<CompletionStage<Void>> ack, Function<Throwable, CompletionStage<Void>> nack) Create a message with the given payload, metadata and ack and nack functions.- Type Parameters:
T
- the type of payload- Parameters:
payload
- The payload.metadata
- the metadata, must not benull
, must not containnull
values.ack
- The ack function, this will be invoked when the returned messagesack()
method is invoked.nack
- The negative-ack function, this will be invoked when the returned messagesnack(Throwable)
method is invoked.- Returns:
- A message with the given payload, metadata, ack and nack functions.
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of
@Experimental("nack support is a SmallRye-only feature") static <T> Message<T> of(T payload, Metadata metadata, Supplier<CompletionStage<Void>> ack, Function<Throwable, CompletionStage<Void>> nack) Create a message with the given payload, metadata and ack and nack functions.- Type Parameters:
T
- the type of payload- Parameters:
payload
- The payload.metadata
- the metadata, must not benull
, must not containnull
values.ack
- The ack function, this will be invoked when the returned messagesack()
method is invoked.nack
- The negative-ack function, this will be invoked when the returned messagesnack(Throwable)
method is invoked.- Returns:
- A message with the given payload, metadata, ack and nack functions.
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withPayload
Creates a new instance ofMessage
with the specified payload. The metadata and ack/nack functions are taken from the currentMessage
.- Type Parameters:
P
- the type of the new payload- Parameters:
payload
- the new payload.- Returns:
- the new instance of
Message
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withMetadata
Creates a new instance ofMessage
with the specified metadata. The payload and ack/nack functions are taken from the currentMessage
.- Parameters:
metadata
- the metadata, must not benull
, must not containsnull
.- Returns:
- the new instance of
Message
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withMetadata
Creates a new instance ofMessage
with the specified metadata. The payload and ack/nack functions are taken from the currentMessage
.- Parameters:
metadata
- the metadata, must not benull
.- Returns:
- the new instance of
Message
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withAck
Creates a new instance ofMessage
with the given acknowledgement supplier. The payload, metadata and nack function are taken from the currentMessage
.- Parameters:
supplier
- the acknowledgement supplier- Returns:
- the new instance of
Message
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withNack
@Experimental("nack support is a SmallRye-only feature") default Message<T> withNack(Function<Throwable, CompletionStage<Void>> nack) Creates a new instance ofMessage
with the given negative-acknowledgement function. The payload, metadata and acknowledgment are taken from the currentMessage
.- Parameters:
nack
- the negative-acknowledgement function- Returns:
- the new instance of
Message
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getPayload
T getPayload()- Returns:
- The payload for this message.
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getMetadata
- Returns:
- The set of metadata attached to this message, potentially empty.
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getMetadata
Retrieves the metadata associated with the given class.- Parameters:
clazz
- the class of the metadata to retrieve, must not benull
- Returns:
- an
Optional
containing the associated metadata, empty if none.
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getAck
- Returns:
- the supplier used to retrieve the acknowledgement
CompletionStage
.
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getNack
@Experimental("nack support is a SmallRye-only feature") default Function<Throwable,CompletionStage<Void>> getNack()- Returns:
- the function used to retrieve the negative-acknowledgement asynchronous function.
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ack
Acknowledge this message.- Returns:
- a completion stage completed when the message is acknowledged. If the acknowledgement fails, the completion stage propagates the failure.
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nack
@Experimental("nack support is a SmallRye-only feature") default CompletionStage<Void> nack(Throwable reason) Acknowledge negatively this message.nack
is used to indicate that the processing of a message failed. The reason is passed as parameter.- Parameters:
reason
- the reason of the nack, must not benull
- Returns:
- a completion stage completed when the message is negative-acknowledgement has completed. If the negative acknowledgement fails, the completion stage propagates the failure.
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nack
@Experimental("nack support is a SmallRye-only feature; metadata propagation is a SmallRye-specific feature") default CompletionStage<Void> nack(Throwable reason, Metadata metadata) Acknowledge negatively this message.nack
is used to indicate that the processing of a message failed. The reason is passed as parameter. Additional metadata may be provided that the connector can use when nacking the message. The interpretation of metadata is connector-specific.- Parameters:
reason
- the reason of the nack, must not benull
metadata
- additional nack metadata the connector may use, may benull
- Returns:
- a completion stage completed when the message is negative-acknowledgement has completed. If the negative acknowledgement fails, the completion stage propagates the failure.
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unwrap
Returns an object of the specified type to allow access to the connector-specificMessage
implementation, and other classes. For example, a Kafka connector could implement this method to allow unwrapping to a specific Kafka message implementation, or toConsumerRecord
andProducerRecord
. If theMessage
implementation does not support the target class, anIllegalArgumentException
should be raised.The default implementation tries to cast the current
Message
instance to the target class. When a connector provides its ownMessage
implementation, it should override this method to support specific types.- Type Parameters:
C
- the target type- Parameters:
unwrapType
- the class of the object to be returned, must not benull
- Returns:
- an instance of the specified class
- Throws:
IllegalArgumentException
- if the currentMessage
instance does not support the call
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addMetadata
Creates a new instance ofMessage
with the current metadata, plus the given one. The payload and ack/nack functions are taken from the currentMessage
.- Parameters:
metadata
- the metadata, must not benull
.- Returns:
- the new instance of
Message
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