Package org.zalando.fahrschein

Class NakadiClient

java.lang.Object

org.zalando.fahrschein.NakadiClient

public class NakadiClient
extends Object

General implementation of the Nakadi Client used within this Library.

Method Summary

Modifier and Type	Method	Description
static NakadiClientBuilder	builder(URI baseUri, org.zalando.fahrschein.http.api.RequestFactory requestFactory)	Returns a new Builder that will make use of the given RequestFactory.
void	deleteSubscription(String subscriptionId)	Delete subscription based on subscription ID.
List<Partition>	getPartitions(String eventName)	Resolves a list of partitions for the given eventName.
<T> void	publish(String eventName, List<T> events)	Writes the given events to the endpoint provided by the eventName.
StreamBuilder.LowLevelStreamBuilder	stream(String eventName)
StreamBuilder.SubscriptionStreamBuilder	stream(Subscription subscription)
Subscription	subscribe(String applicationName, String eventName, String consumerGroup)	Deprecated. Use the SubscriptionBuilder and subscription(String, String) instead.
SubscriptionBuilder	subscription(String applicationName, String eventName)	Build a subscription for a single event type.
SubscriptionBuilder	subscription(String applicationName, Set<String> eventNames)	Build a subscription for multiple event types.

Methods inherited from class java.lang.Object

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

Method Details

builder

public static NakadiClientBuilder builder(URI baseUri,
 org.zalando.fahrschein.http.api.RequestFactory requestFactory)

Returns a new Builder that will make use of the given RequestFactory.

Parameters:

baseUri - that we will send requests to

requestFactory - that we use for the execution of our HTTP Requests.

Returns:

A builder to initialize the client. Can be further modified later.

getPartitions

public List<Partition> getPartitions(String eventName)
                              throws IOException

Resolves a list of partitions for the given eventName.

Parameters:

eventName - that we want to resolve the partitions for.

Returns:

List<Partition> or null in

Throws:

IOException - in case of network issues.

publish

public <T> void publish(String eventName,
 List<T> events)
                 throws EventPublishingException,
IOException

Writes the given events to the endpoint provided by the eventName.

In case of a partial success (or also in cases like validation errors, which are complete failures), Fahrschein will throw an EventPublishingException with the BatchItemResponses (as returned from Nakadi) for the failed items in the responses property. These objects have the eid of the failed event, a publishingStatus (failed/aborted/submitted - but successful items are filtered out), the step where it failed and a detail string. If the application sets the eids itself (i.e. doesn't let Nakadi do it) and keeps track of them, this allows it to resend only the failed items later. It also allows differentiating between validation errors, which likely don't need to be retried, as they are unlikely to succeed the next time, unless the event type definition is changed, and publishing errors which should be retried with some back-off.

Recommendation: Implement a retry-with-backoff handler for EventPublishingExceptions, which, depending on your ordering consistency requirements, either retries the full batch, or retries the failed events based on the event-ids.

Type Parameters:

T - Type of the Event

Parameters:

eventName - where the event should be written to

events - that should be written

Throws:

IOException - in case we fail to reach Nakadi

EventPublishingException - In case Nakadi returns an Erroneous response

subscribe

@Deprecated
public Subscription subscribe(String applicationName,
 String eventName,
 String consumerGroup)
                       throws IOException

Deprecated.

Use the SubscriptionBuilder and subscription(String, String) instead.

Create a subscription for a single event type.

Throws:

IOException

subscription

public SubscriptionBuilder subscription(String applicationName,
 String eventName)
                                 throws IOException

Build a subscription for a single event type.

Throws:

IOException

subscription

public SubscriptionBuilder subscription(String applicationName,
 Set<String> eventNames)
                                 throws IOException

Build a subscription for multiple event types.

Throws:

IOException

deleteSubscription

public void deleteSubscription(String subscriptionId)
                        throws IOException

Delete subscription based on subscription ID.

Throws:

IOException

stream

public StreamBuilder.SubscriptionStreamBuilder stream(Subscription subscription)

stream

public StreamBuilder.LowLevelStreamBuilder stream(String eventName)