Class KafkaListener

java.lang.Object

org.frankframework.extensions.kafka.AbstractKafkaFacade

org.frankframework.extensions.kafka.KafkaListener

All Implemented Interfaces:

FrankElement, HasApplicationContext, HasName, HasPhysicalDestination, IConfigurable, IListener<org.apache.kafka.clients.consumer.ConsumerRecord<String,byte[]>>, IPullingListener<org.apache.kafka.clients.consumer.ConsumerRecord<String,byte[]>>, IScopeProvider, NameAware, org.springframework.beans.factory.Aware, org.springframework.context.ApplicationContextAware

@Category(EXPERIMENTAL)
@ConfigurationWarning("Experimental and under development. Do not use unless you wish to participate in this development.")
public class KafkaListener
extends AbstractKafkaFacade
implements IPullingListener<org.apache.kafka.clients.consumer.ConsumerRecord<String,byte[]>>

Experimental IListener for listening to a topic in a Kafka instance. The Kafka integration is still under development so do not currently use unless you wish to participate in this development.

Field Summary

Fields inherited from class AbstractKafkaFacade

properties

Constructor Summary

Constructors

Constructor	Description
KafkaListener()

Method Summary

Modifier and Type	Method	Description
void	afterMessageProcessed(PipeLineResult processResult, RawMessageWrapper<org.apache.kafka.clients.consumer.ConsumerRecord<String,byte[]>> rawMessage, PipeLineSession pipeLineSession)	Called to perform actions (like committing or sending a reply) after a message has been processed by the Pipeline.
protected org.apache.kafka.clients.consumer.Consumer<String,byte[]>	buildConsumer()
void	closeThread(@NonNull Map<String,Object> threadContext)	Finalizes a message receiving thread.
void	configure()	Configure this component.
Message	extractMessage(@NonNull RawMessageWrapper<org.apache.kafka.clients.consumer.ConsumerRecord<String,byte[]>> wrappedMessage, @NonNull Map<String,Object> threadContext)	Extracts data from message obtained from IPullingListener.getRawMessage(Map) or IPushingListener.wrapRawMessage(Object, PipeLineSession).
String	getPhysicalDestinationName()
@Nullable RawMessageWrapper<org.apache.kafka.clients.consumer.ConsumerRecord<String,byte[]>>	getRawMessage(@NonNull Map<String,Object> threadContext)	Retrieves messages from queue or other channel, but does no processing on it.
@NonNull Map<String,Object>	openThread()	Prepares a thread for receiving messages.
void	start()	Prepares the listener for receiving messages.
void	stop()	Close all resources used for listening.

Methods inherited from class AbstractKafkaFacade

checkConnection

Methods inherited from class Object

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

Methods inherited from interface org.springframework.context.ApplicationContextAware

setApplicationContext

Methods inherited from interface FrankElement

addConfigWarning

Methods inherited from interface HasApplicationContext

getApplicationContext, getConfigurationClassLoader

Methods inherited from interface HasName

getName

Methods inherited from interface NameAware

setName

Constructor Details

KafkaListener

public KafkaListener()

Method Details

configure

public void configure()
               throws ConfigurationException

Description copied from interface: IConfigurable

Configure this component.

configure() is called once at startup of the framework in the configure method of the owner of this IConfigurable. Purpose of this method is to check whether the static configuration of the object is correct. As much as possible class-instantiating should take place in the configure(), to improve performance.

In the case of a container, this will propagate the configure signal to all components that apply.

Specified by:

configure in interface IConfigurable

Overrides:

configure in class AbstractKafkaFacade

Throws:

ConfigurationException - in case it was not able to configure the component.

start

public void start()

Description copied from interface: IListener

Prepares the listener for receiving messages. start() is called once each time the listener is started.

Specified by:

start in interface IListener<org.apache.kafka.clients.consumer.ConsumerRecord<String,byte[]>>

buildConsumer

protected org.apache.kafka.clients.consumer.Consumer<String,byte[]> buildConsumer()

stop

public void stop()

Description copied from interface: IListener

Close all resources used for listening. Called once each time the listener is stopped.

Specified by:

stop in interface IListener<org.apache.kafka.clients.consumer.ConsumerRecord<String,byte[]>>

extractMessage

public Message extractMessage(@NonNull RawMessageWrapper<org.apache.kafka.clients.consumer.ConsumerRecord<String,byte[]>> wrappedMessage,
 @NonNull Map<String,Object> threadContext)

Description copied from interface: IListener

Extracts data from message obtained from IPullingListener.getRawMessage(Map) or IPushingListener.wrapRawMessage(Object, PipeLineSession). May also extract other parameters from the message and put those into the context.

The Receiver does not call this method when the listener implementation returned an instance of MessageWrapper from IPullingListener.getRawMessage(Map) or * IPushingListener.wrapRawMessage(Object, PipeLineSession).

Specified by:

extractMessage in interface IListener<org.apache.kafka.clients.consumer.ConsumerRecord<String,byte[]>>

Parameters:

wrappedMessage - The RawMessageWrapper from which to extract the Message.

threadContext - Context to populate. Either a PipeLineSession or a Map threadContext depending on caller.

Returns:

input Message for adapter.

afterMessageProcessed

public void afterMessageProcessed(PipeLineResult processResult,
 RawMessageWrapper<org.apache.kafka.clients.consumer.ConsumerRecord<String,byte[]>> rawMessage,
 PipeLineSession pipeLineSession)

Description copied from interface: IListener

Called to perform actions (like committing or sending a reply) after a message has been processed by the Pipeline.

Specified by:

afterMessageProcessed in interface IListener<org.apache.kafka.clients.consumer.ConsumerRecord<String,byte[]>>

getPhysicalDestinationName

public String getPhysicalDestinationName()

Specified by:

getPhysicalDestinationName in interface HasPhysicalDestination

openThread

public @NonNull Map<String,Object> openThread()

Description copied from interface: IPullingListener

Prepares a thread for receiving messages. Called once for each thread that will listen for messages.

Specified by:

openThread in interface IPullingListener<org.apache.kafka.clients.consumer.ConsumerRecord<String,byte[]>>

Returns:

the threadContext for this thread. The threadContext is a Map in which thread-specific data can be stored. May not be null, must be a mutable map type.

closeThread

public void closeThread(@NonNull Map<String,Object> threadContext)

Description copied from interface: IPullingListener

Finalizes a message receiving thread. Called once for each thread that listens for messages, just before IListener.stop() is called.

Specified by:

closeThread in interface IPullingListener<org.apache.kafka.clients.consumer.ConsumerRecord<String,byte[]>>

getRawMessage

public @Nullable RawMessageWrapper<org.apache.kafka.clients.consumer.ConsumerRecord<String,byte[]>> getRawMessage(@NonNull Map<String,Object> threadContext)

Description copied from interface: IPullingListener

Retrieves messages from queue or other channel, but does no processing on it. Multiple objects may try to call this method at the same time, from different threads. Implementations of this method should therefore be thread-safe, or synchronized.

Any thread-specific properties should be stored in and retrieved from the threadContext.

If the returned object is an instance of MessageWrapper then the Receiver.processRawMessage(IListener, RawMessageWrapper, PipeLineSession, boolean) will not call IListener.extractMessage(RawMessageWrapper, Map) but directly access the enclosed Message and the

invalid reference

RawMessageWrapper#getContext()

.

Specified by:

getRawMessage in interface IPullingListener<org.apache.kafka.clients.consumer.ConsumerRecord<String,byte[]>>