Package de.otto.synapse.endpoint.receiver

Class DelegateMessageLogReceiverEndpoint

java.lang.Object

de.otto.synapse.endpoint.receiver.DelegateMessageLogReceiverEndpoint

All Implemented Interfaces:

MessageEndpoint, MessageLogReceiverEndpoint, MessageReceiverEndpoint

public class DelegateMessageLogReceiverEndpoint
extends java.lang.Object
implements MessageLogReceiverEndpoint

Constructor Summary

Constructors

Constructor	Description
DelegateMessageLogReceiverEndpoint(java.lang.String channelName, MessageLogReceiverEndpointFactory messageLogReceiverEndpointFactory)

Method Summary

Modifier and Type	Method	Description
java.util.concurrent.CompletableFuture<ChannelPosition>	consumeUntil(ChannelPosition startFrom, java.util.function.Predicate<ShardResponse> stopCondition)	Beginning at the startFrom position, messages are consumed from the message log, until the stopCondition is true.
java.lang.String	getChannelName()	Returns the name of the channel.
EndpointType	getEndpointType()	Returns the type of the MessageEndpoint, either EndpointType.SENDER or EndpointType.RECEIVER.
InterceptorChain	getInterceptorChain()	Returns the InterceptorChain of the MessageEndpoint.
MessageDispatcher	getMessageDispatcher()	Returns the MessageDispatcher that is used to dispatch messages.
TextMessage	intercept(TextMessage message)	Intercepts a message using all registered interceptors and returns the resulting message.
void	register(MessageConsumer<?> messageConsumer)	Registers a MessageConsumer at the receiver endpoint.
void	stop()	Stops consumption of messages and shuts down the MessageLogReceiverEndpoint.

Methods inherited from class java.lang.Object

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

Methods inherited from interface de.otto.synapse.endpoint.receiver.MessageLogReceiverEndpoint

consume

Constructor Detail

DelegateMessageLogReceiverEndpoint

public DelegateMessageLogReceiverEndpoint(@Nonnull
                                          java.lang.String channelName,
                                          @Nonnull
                                          MessageLogReceiverEndpointFactory messageLogReceiverEndpointFactory)

Method Detail

consumeUntil

@Nonnull
public java.util.concurrent.CompletableFuture<ChannelPosition> consumeUntil(@Nonnull
                                                                            ChannelPosition startFrom,
                                                                            @Nonnull
                                                                            java.util.function.Predicate<ShardResponse> stopCondition)

Description copied from interface: MessageLogReceiverEndpoint

Beginning at the startFrom position, messages are consumed from the message log, until the stopCondition is true.

If the message-log is sharded, the predicate must be true for every shard: otherwise, message consumption would continue on other shards.

Takes zero or more messages from the channel, calls MessageEndpoint.intercept(TextMessage) for every message, and notifies the registered consumers with the intercepted message, or drops the message, if intercept returns null.

Consumption starts with the first message after startFrom and finishes when either the stopCondition is met, or the application is shutting down.

The returned ChannelPosition is the position of the last message that was processed by the MessageLogReceiverEndpoint - whether it was dropped or consumed.

The registered consumers are used as a callback for consumed messages. A MessageDispatcher can be used as a consumer, if multiple consumers, or consumers with message payloads other than String are required.

Specified by:

consumeUntil in interface MessageLogReceiverEndpoint

Parameters:

startFrom - the start position used to proceed message consumption

stopCondition - the predicate used to test if message consumption should be stopped. In most cases, the predicates defined in StopCondition should be sufficient.

Returns:

ChannelPosition

stop

public void stop()

Description copied from interface: MessageLogReceiverEndpoint

Stops consumption of messages and shuts down the MessageLogReceiverEndpoint.

Specified by:

stop in interface MessageLogReceiverEndpoint

register

public void register(MessageConsumer<?> messageConsumer)

Description copied from interface: MessageReceiverEndpoint

Registers a MessageConsumer at the receiver endpoint. consumers have to be thread safe as they might be called from multiple threads in parallel (e.g. for kinesis streams there is one thread per shard).

Specified by:

register in interface MessageReceiverEndpoint

Parameters:

messageConsumer - registered EventConsumer

getMessageDispatcher

@Nonnull
public MessageDispatcher getMessageDispatcher()

Description copied from interface: MessageReceiverEndpoint

Returns the MessageDispatcher that is used to dispatch messages.

Specified by:

getMessageDispatcher in interface MessageReceiverEndpoint

Returns:

MessageDispatcher

getChannelName

@Nonnull
public java.lang.String getChannelName()

Description copied from interface: MessageEndpoint

Returns the name of the channel.

The channel name corresponds to the name of the underlying stream, queue or message log.

Specified by:

getChannelName in interface MessageEndpoint

Returns:

name of the channel

getInterceptorChain

@Nonnull
public InterceptorChain getInterceptorChain()

Description copied from interface: MessageEndpoint

Returns the InterceptorChain of the MessageEndpoint.

Specified by:

getInterceptorChain in interface MessageEndpoint

Returns:

InterceptorChain

getEndpointType

@Nonnull
public EndpointType getEndpointType()

Description copied from interface: MessageEndpoint

Returns the type of the MessageEndpoint, either EndpointType.SENDER or EndpointType.RECEIVER.

Specified by:

getEndpointType in interface MessageEndpoint

Returns:

EndpointType

intercept

@Nullable
public TextMessage intercept(@Nonnull
                             TextMessage message)

Description copied from interface: MessageEndpoint

Intercepts a message using all registered interceptors and returns the resulting message.

The interceptors are called in order. The result of one interceptor is propagated to the next interceptor in the chain, until the end of the chain is reached, or one interceptor has returned null.

If null is returned, the message must be dropped by the AbstractMessageEndpoint.

Every interceptor may transform the message, or may take additional actions like, for example, logging, monitoring or other things.

Specified by:

intercept in interface MessageEndpoint

Parameters:

message - the message to intercept

Returns:

the (possibly modified) message, or null if the message should be dropped.