io.cloudevents.core.message

Interface MessageReader

All Superinterfaces:

CloudEventReader, StructuredMessageReader

All Known Implementing Classes:

BaseBinaryMessageReader, BaseGenericBinaryMessageReaderImpl, BaseStructuredMessageReader, GenericStructuredMessageReader, UnknownEncodingMessageReader

@ParametersAreNonnullByDefault
public interface MessageReader
extends StructuredMessageReader, CloudEventReader

Represents a CloudEvent message.

Method Summary

Modifier and Type	Method and Description
Encoding	getEncoding()
<V extends CloudEventWriter<R>,R> R	read(CloudEventWriterFactory<V,R> writerFactory) Visit the message as binary encoded event using the provided visitor factory.
<T> T	read(StructuredMessageWriter<T> visitor) Visit the message as structured encoded event using the provided visitor
void	readAttributes(CloudEventAttributesWriter writer) Visit the message attributes as binary encoded event using the provided visitor.
void	readExtensions(CloudEventExtensionsWriter visitor) Visit the message extensions as binary encoded event using the provided visitor.
default CloudEvent	toEvent() Translate this message into a CloudEvent representation.
default <BV extends CloudEventWriter<R>,R> R	visit(MessageWriter<BV,R> visitor) Visit the event using a MessageWriter.

Methods inherited from interface io.cloudevents.core.message.StructuredMessageReader

from, from

Method Detail

read

<V extends CloudEventWriter<R>,R> R read(CloudEventWriterFactory<V,R> writerFactory)
                                  throws CloudEventRWException,
                                         IllegalStateException

Visit the message as binary encoded event using the provided visitor factory.

Specified by:

read in interface CloudEventReader

Parameters:

writerFactory - a factory that generates a visitor starting from the SpecVersion of the event

Throws:

CloudEventRWException - if something went wrong during the visit.

IllegalStateException - if the message is not in binary encoding.

readAttributes

void readAttributes(CloudEventAttributesWriter writer)
             throws CloudEventRWException,
                    IllegalStateException

Visit the message attributes as binary encoded event using the provided visitor.

Specified by:

readAttributes in interface CloudEventReader

Parameters:

writer - Attributes visitor

Throws:

CloudEventRWException - if something went wrong during the visit.

IllegalStateException - if the message is not in binary encoding.

readExtensions

void readExtensions(CloudEventExtensionsWriter visitor)
             throws CloudEventRWException,
                    IllegalStateException

Visit the message extensions as binary encoded event using the provided visitor.

Specified by:

readExtensions in interface CloudEventReader

Parameters:

visitor - Extensions visitor

Throws:

CloudEventRWException - if something went wrong during the visit.

IllegalStateException - if the message is not in binary encoding.

read

<T> T read(StructuredMessageWriter<T> visitor)
    throws CloudEventRWException,
           IllegalStateException

Visit the message as structured encoded event using the provided visitor

Specified by:

read in interface StructuredMessageReader

Parameters:

visitor - Structured Message visitor

Throws:

CloudEventRWException - if something went wrong during the visit.

IllegalStateException - if the message is not in structured encoding.

getEncoding

Encoding getEncoding()

Returns:

The message encoding

visit

default <BV extends CloudEventWriter<R>,R> R visit(MessageWriter<BV,R> visitor)
                                            throws CloudEventRWException,
                                                   IllegalStateException

Visit the event using a MessageWriter. This method allows to transcode an event from one transport to another without converting it to CloudEvent. The resulting encoding will be the same as the original encoding.

Parameters:

visitor - the MessageVisitor accepting this Message

Returns:

The return value of the MessageVisitor

Throws:

CloudEventRWException - if something went wrong during the visit.

IllegalStateException - if the message has an unknown encoding.

toEvent

default CloudEvent toEvent()
                    throws CloudEventRWException,
                           IllegalStateException

Translate this message into a CloudEvent representation.

Specified by:

toEvent in interface StructuredMessageReader

Returns:

A CloudEvent with the contents of this message.

Throws:

CloudEventRWException - if something went wrong during the visit.

IllegalStateException - if the message has an unknown encoding.