org.wikimedia.eventutilities.core.event

Class JsonEventGenerator

java.lang.Object

org.wikimedia.eventutilities.core.event.JsonEventGenerator

@ParametersAreNonnullByDefault
public final class JsonEventGenerator
extends Object

Helper class suited to assist java clients producing json events directly to kafka. This object must be constructed using builder(). It provides: - initialization of default values - meta.dt as the kafka ingestion time with the provided clock - meta.stream - dt as a yet optional event time provided via a param - $schema as the schema that can validate the generated event - verification of schema vs stream - validation of the event against its schema

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	JsonEventGenerator.Builder
static interface	JsonEventGenerator.EventNormalizer A component that applies various normalization and verification steps to the events it receives.

Field Summary

Fields

Modifier and Type	Field and Description
static String	EVENT_TIME_FIELD
static String	META_FIELD
static String	META_ID_FIELD
static String	META_INGESTION_TIME_FIELD
static String	META_STREAM_FIELD
static String	SCHEMA_FIELD

Method Summary

Modifier and Type	Method and Description
static JsonEventGenerator.Builder	builder()
JsonEventGenerator.EventNormalizer	createEventStreamEventGenerator(String streamName, String schemaUri) Create a validating event generator.
JsonEventGenerator.EventNormalizer	createNonValidatingEventStreamEventGenerator(String streamName, String schemaUri) Create a non-validating event generator.
com.fasterxml.jackson.databind.node.ObjectNode	generateEvent(String streamName, String schemaUri, Consumer<com.fasterxml.jackson.databind.node.ObjectNode> eventData, Instant eventTime) Generates an json event calling the supplier eventData.
com.fasterxml.jackson.databind.node.ObjectNode	generateEvent(String streamName, String schemaUri, Consumer<com.fasterxml.jackson.databind.node.ObjectNode> eventData, Instant eventTime, boolean validate) Generates a json event calling the supplier eventData.
com.fasterxml.jackson.databind.ObjectMapper	getJsonMapper()
byte[]	serializeAsBytes(com.fasterxml.jackson.databind.node.ObjectNode root) Helper method to serialize the event as bytes.

Methods inherited from class java.lang.Object

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

Field Detail

SCHEMA_FIELD

public static final String SCHEMA_FIELD

See Also:

Constant Field Values

EVENT_TIME_FIELD

public static final String EVENT_TIME_FIELD

See Also:

Constant Field Values

META_FIELD

public static final String META_FIELD

See Also:

Constant Field Values

META_STREAM_FIELD

public static final String META_STREAM_FIELD

See Also:

Constant Field Values

META_INGESTION_TIME_FIELD

public static final String META_INGESTION_TIME_FIELD

See Also:

Constant Field Values

META_ID_FIELD

public static final String META_ID_FIELD

See Also:

Constant Field Values

Method Detail

generateEvent

public com.fasterxml.jackson.databind.node.ObjectNode generateEvent(String streamName,
                                                                    String schemaUri,
                                                                    Consumer<com.fasterxml.jackson.databind.node.ObjectNode> eventData,
                                                                    @Nullable
                                                                    Instant eventTime)

Generates an json event calling the supplier eventData.

Parameters:

streamName - the stream this event will be pushed to

schemaUri - the schema this event is build against

eventData - consumer receiving an empty ObjectNode to attach data to

eventTime - the optional eventTime to be set to the dt field (might become mandatory)

Throws:

IllegalArgumentException - if the schema does not match what is expected from the stream configuration

IllegalArgumentException - if the schema cannot be found/loaded

IllegalArgumentException - if the event is not valid against the provided schema

generateEvent

public com.fasterxml.jackson.databind.node.ObjectNode generateEvent(String streamName,
                                                                    String schemaUri,
                                                                    Consumer<com.fasterxml.jackson.databind.node.ObjectNode> eventData,
                                                                    @Nullable
                                                                    Instant eventTime,
                                                                    boolean validate)

Generates a json event calling the supplier eventData. Using this method with validate to false is highly discouraged and should only be used when shipping events to event-gate that will take care of the schema validation.

Parameters:

streamName - the stream this event will be pushed to

schemaUri - the schema this event is build against

eventData - consumer receiving an empty ObjectNode to attach data to

eventTime - the optional eventTime to be set to the dt field (might become mandatory)

validate - true to validate the event against its schema

Throws:

IllegalArgumentException - if the schema does not match what is expected from the stream configuration

IllegalArgumentException - if the schema cannot be found/loaded

IllegalArgumentException - if the event is not valid against the provided schema

createEventStreamEventGenerator

public JsonEventGenerator.EventNormalizer createEventStreamEventGenerator(String streamName,
                                                                          String schemaUri)

Create a validating event generator. Suited to ship events directly to kafka

createNonValidatingEventStreamEventGenerator

public JsonEventGenerator.EventNormalizer createNonValidatingEventStreamEventGenerator(String streamName,
                                                                                       String schemaUri)

Create a non-validating event generator. Use with care, this should ONLY be used to send event via event-gate which will perform schema validation. Using this to ship events directly to kafka must never be used.

serializeAsBytes

public byte[] serializeAsBytes(com.fasterxml.jackson.databind.node.ObjectNode root)
                        throws IOException

Helper method to serialize the event as bytes.

Throws:

IOException

builder

public static JsonEventGenerator.Builder builder()

getJsonMapper

public com.fasterxml.jackson.databind.ObjectMapper getJsonMapper()