EventGridEvent.java
// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.
package com.azure.messaging.eventgrid;
import com.azure.core.annotation.Fluent;
import com.azure.core.util.BinaryData;
import com.azure.core.util.logging.ClientLogger;
import com.azure.core.util.serializer.JacksonAdapter;
import com.azure.core.util.serializer.JsonSerializer;
import com.azure.core.util.serializer.JsonSerializerProviders;
import com.azure.core.util.serializer.SerializerAdapter;
import com.azure.core.util.serializer.SerializerEncoding;
import com.azure.core.util.serializer.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import reactor.core.publisher.Mono;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UncheckedIOException;
import java.nio.charset.StandardCharsets;
import java.time.OffsetDateTime;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.UUID;
/**
* Represents the EventGrid event conforming to the <a href="https://docs.microsoft.com/azure/event-grid/event-schema">
* EventGrid event schema</a>.
*
* <p>Depending on your scenario, you can either use the constructor
* {@link #EventGridEvent(String, String, BinaryData, String)} to create an EventGridEvent,
* or use the factory method {@link #fromString(String)} to deserialize EventGridEvent instances
* from a Json String representation of EventGrid events.</p>
*
* <p>If you have the data payload of an EventGridEvent and want to send it out, use the constructor
* {@link #EventGridEvent(String, String, BinaryData, String)} to create it. Then use
* {@link EventGridPublisherAsyncClient} or {@link EventGridPublisherClient} to send it the EventGrid service.</p>
*
* <p><strong>Create EventGridEvent Samples</strong></p>
* <!-- src_embed com.azure.messaging.eventgrid.EventGridEvent#constructor -->
* <pre>
* // Use BinaryData.fromObject() to create EventGridEvent data
* // From a model class
* User user = new User("Stephen", "James");
* EventGridEvent eventGridEventDataObject = new EventGridEvent("/EventGridEvents/example/source",
* "Example.EventType", BinaryData.fromObject(user), "0.1");
*
* // From a String
* EventGridEvent eventGridEventDataStr = new EventGridEvent("/EventGridEvents/example/source",
* "Example.EventType", BinaryData.fromObject("Hello World"), "0.1");
*
* // From an Integer
* EventGridEvent eventGridEventDataInt = new EventGridEvent("/EventGridEvents/example/source",
* "Example.EventType", BinaryData.fromObject(1), "0.1");
*
* // From a Boolean
* EventGridEvent eventGridEventDataBool = new EventGridEvent("/EventGridEvents/example/source",
* "Example.EventType", BinaryData.fromObject(true), "0.1");
*
* // From null
* EventGridEvent eventGridEventDataNull = new EventGridEvent("/EventGridEvents/example/source",
* "Example.EventType", BinaryData.fromObject(null), "0.1");
*
* // Use BinaryData.fromString() if you have a Json String for the EventGridEvent data.
* String jsonStringForData = "\"Hello World\""; // A json String.
* EventGridEvent eventGridEventDataDataJsonStr = new EventGridEvent("/EventGridEvents/example/source",
* "Example.EventType", BinaryData.fromString(jsonStringForData), "0.1");
* </pre>
* <!-- end com.azure.messaging.eventgrid.EventGridEvent#constructor -->
*
* <p>On the contrary, if you receive events from any event handlers and therefore have the Json string representation
* of one or more of EventGridEvents, use {@link #fromString(String)} to deserialize them from the Json string.</p>
*
* <p><strong>Deserialize EventGridEvent Samples</strong></p>
* <!-- src_embed com.azure.messaging.eventgrid.EventGridEvent.fromString -->
* <pre>
* List<EventGridEvent> eventGridEventList = EventGridEvent.fromString(eventGridEventJsonString);
* EventGridEvent eventGridEvent = eventGridEventList.get(0);
* BinaryData eventGridEventData = eventGridEvent.getData();
*
* User objectValue = eventGridEventData.toObject(User.class); // If data payload is a User object.
* int intValue = eventGridEventData.toObject(Integer.class); // If data payload is an int.
* boolean boolValue = eventGridEventData.toObject(Boolean.class); // If data payload is boolean.
* String stringValue = eventGridEventData.toObject(String.class); // If data payload is String.
* String jsonStringValue = eventGridEventData.toString(); // The data payload represented in Json String.
* </pre>
* <!-- end com.azure.messaging.eventgrid.EventGridEvent.fromString -->
*
* @see EventGridPublisherAsyncClient to send EventGridEvents asynchronously.
* @see EventGridPublisherClient to send EventGridEvents sychronously.
**/
@Fluent
public final class EventGridEvent {
private final com.azure.messaging.eventgrid.implementation.models.EventGridEvent event;
private static final ClientLogger LOGGER = new ClientLogger(EventGridEvent.class);
private static final JsonSerializer SERIALIZER;
static {
JsonSerializer tmp;
try {
tmp = JsonSerializerProviders.createInstance();
} catch (IllegalStateException e) {
tmp = new JacksonSerializer();
}
SERIALIZER = tmp;
}
private static final TypeReference<List<com.azure.messaging.eventgrid.implementation.models.EventGridEvent>>
DESERIALIZER_TYPE_REFERENCE =
new TypeReference<List<com.azure.messaging.eventgrid.implementation.models.EventGridEvent>>() {
};
// May get SERIALIZER's object mapper in the future.
private static final ObjectMapper BINARY_DATA_OBJECT_MAPPER = new ObjectMapper();
/*
* Cache serialized data for getData()
*/
private BinaryData binaryData;
/**
* Create a new instance of the EventGridEvent, with the given required fields.
*
* <p><strong>Create EventGridEvent Samples</strong></p>
* <!-- src_embed com.azure.messaging.eventgrid.EventGridEvent#constructor -->
* <pre>
* // Use BinaryData.fromObject() to create EventGridEvent data
* // From a model class
* User user = new User("Stephen", "James");
* EventGridEvent eventGridEventDataObject = new EventGridEvent("/EventGridEvents/example/source",
* "Example.EventType", BinaryData.fromObject(user), "0.1");
*
* // From a String
* EventGridEvent eventGridEventDataStr = new EventGridEvent("/EventGridEvents/example/source",
* "Example.EventType", BinaryData.fromObject("Hello World"), "0.1");
*
* // From an Integer
* EventGridEvent eventGridEventDataInt = new EventGridEvent("/EventGridEvents/example/source",
* "Example.EventType", BinaryData.fromObject(1), "0.1");
*
* // From a Boolean
* EventGridEvent eventGridEventDataBool = new EventGridEvent("/EventGridEvents/example/source",
* "Example.EventType", BinaryData.fromObject(true), "0.1");
*
* // From null
* EventGridEvent eventGridEventDataNull = new EventGridEvent("/EventGridEvents/example/source",
* "Example.EventType", BinaryData.fromObject(null), "0.1");
*
* // Use BinaryData.fromString() if you have a Json String for the EventGridEvent data.
* String jsonStringForData = "\"Hello World\""; // A json String.
* EventGridEvent eventGridEventDataDataJsonStr = new EventGridEvent("/EventGridEvents/example/source",
* "Example.EventType", BinaryData.fromString(jsonStringForData), "0.1");
* </pre>
* <!-- end com.azure.messaging.eventgrid.EventGridEvent#constructor -->
*
* @param subject the subject of the event.
* @param eventType the type of the event, e.g. "Contoso.Items.ItemReceived".
* @param data the data associated with this event. The content of this {@link BinaryData} must be a Json value.
* @param dataVersion the version of the data sent along with the event.
*
* @throws NullPointerException if subject, eventType, data, or dataVersion is {@code null}.
* @throws IllegalArgumentException if the content of data isn't a Json value.
*/
public EventGridEvent(String subject, String eventType, BinaryData data, String dataVersion) {
Objects.requireNonNull(subject, "'subject' cannot be null.");
Objects.requireNonNull(eventType, "'eventType' cannot be null.");
Objects.requireNonNull(data, "'data' cannot be null");
Objects.requireNonNull(dataVersion, "'dataVersion' cannot be null");
this.event = new com.azure.messaging.eventgrid.implementation.models.EventGridEvent()
.setEventTime(OffsetDateTime.now())
.setId(UUID.randomUUID().toString())
.setSubject(subject)
.setEventType(eventType)
.setDataVersion(dataVersion);
this.binaryData = data;
try {
this.event.setData(BINARY_DATA_OBJECT_MAPPER.readTree(data.toBytes()));
} catch (IOException e) {
throw LOGGER.logExceptionAsError(new IllegalArgumentException("'data' isn't in valid Json format",
e));
}
}
/**
* Deserialize {@link EventGridEvent} JSON string representation that has one EventGridEvent object or
* an array of CloudEvent objects into a list of EventGridEvents.
*
* <p><strong>Deserialize EventGridEvent Samples</strong></p>
* <!-- src_embed com.azure.messaging.eventgrid.EventGridEvent.fromString -->
* <pre>
* List<EventGridEvent> eventGridEventList = EventGridEvent.fromString(eventGridEventJsonString);
* EventGridEvent eventGridEvent = eventGridEventList.get(0);
* BinaryData eventGridEventData = eventGridEvent.getData();
*
* User objectValue = eventGridEventData.toObject(User.class); // If data payload is a User object.
* int intValue = eventGridEventData.toObject(Integer.class); // If data payload is an int.
* boolean boolValue = eventGridEventData.toObject(Boolean.class); // If data payload is boolean.
* String stringValue = eventGridEventData.toObject(String.class); // If data payload is String.
* String jsonStringValue = eventGridEventData.toString(); // The data payload represented in Json String.
* </pre>
* <!-- end com.azure.messaging.eventgrid.EventGridEvent.fromString -->
*
* @param eventGridJsonString the JSON string containing one or more EventGridEvent objects.
*
* @return A list of {@link EventGridEvent EventGridEvents} deserialized from eventGridJsonString.
* @throws IllegalArgumentException if eventGridJsonString isn't a JSON string for a eventgrid event
* or an array of it.
* @throws NullPointerException if eventGridJsonString is {@code null}.
* @throws IllegalArgumentException if the {eventGridJsonString isn't a Json string or can't be deserialized
* into valid EventGridEvent instances.
*/
public static List<EventGridEvent> fromString(String eventGridJsonString) {
try {
List<com.azure.messaging.eventgrid.implementation.models.EventGridEvent> internalEvents =
SERIALIZER.deserialize(new ByteArrayInputStream(eventGridJsonString.getBytes(StandardCharsets.UTF_8)),
DESERIALIZER_TYPE_REFERENCE);
List<EventGridEvent> events = new ArrayList<EventGridEvent>();
for (int i = 0; i < internalEvents.size(); i++) {
com.azure.messaging.eventgrid.implementation.models.EventGridEvent internalEvent =
internalEvents.get(i);
if (internalEvent.getSubject() == null || internalEvent.getEventType() == null
|| internalEvent.getData() == null || internalEvent.getDataVersion() == null) {
List<String> nullAttributes = new ArrayList<String>();
if (internalEvent.getSubject() == null) {
nullAttributes.add("'subject'");
}
if (internalEvent.getEventType() == null) {
nullAttributes.add("'eventType'");
}
if (internalEvent.getData() == null) {
nullAttributes.add("'data'");
}
if (internalEvent.getDataVersion() == null) {
nullAttributes.add("'dataVersion'");
}
throw LOGGER.logExceptionAsError(new IllegalArgumentException(
"'subject', 'eventType', 'data' and 'dataVersion' are mandatory attributes for an "
+ "EventGridEvent. This Json string doesn't have "
+ String.join(",", nullAttributes)
+ " for the object at index " + i
+ ". Please make sure the input Json string has the required attributes"));
}
events.add(new EventGridEvent(internalEvent));
}
return events;
} catch (UncheckedIOException uncheckedIOException) {
throw LOGGER.logExceptionAsError(new IllegalArgumentException("The input parameter isn't a JSON string.",
uncheckedIOException.getCause()));
}
}
/**
* Get the unique id associated with this event.
* @return the id.
*/
public String getId() {
return this.event.getId();
}
/**
* Set the unique id of the event. Note that a random id has already been set by default.
* @param id the unique id to set.
*
* @return the event itself.
* @throws NullPointerException if id is null.
* @throws IllegalArgumentException if id is an empty String.
*/
public EventGridEvent setId(String id) {
Objects.requireNonNull(id, "'id' cannot be null.");
if (id.isEmpty()) {
throw LOGGER.logExceptionAsError(new IllegalArgumentException("'id' cannot be empty."));
}
this.event.setId(id);
return this;
}
/**
* Get the topic associated with this event if it is associated with a domain.
* @return the topic, or null if the topic is not set.
*/
public String getTopic() {
return this.event.getTopic();
}
/**
* Set the topic associated with this event. Used to route events from domain endpoints.
* @param topic the topic to set.
*
* @return the event itself.
*/
public EventGridEvent setTopic(String topic) {
this.event.setTopic(topic);
return this;
}
/**
* Get the subject associated with this event.
* @return the subject.
*/
public String getSubject() {
return this.event.getSubject();
}
/**
* Get the data associated with this event as a {@link BinaryData}, which has API to deserialize the data to
* any objects by using {@link BinaryData#toObject(TypeReference)}.
* @return A {@link BinaryData} that wraps the this event's data payload.
*/
public BinaryData getData() {
if (this.binaryData == null) {
Object data = this.event.getData();
if (data != null) {
this.binaryData = BinaryData.fromObject(data, SERIALIZER);
}
}
return this.binaryData;
}
/**
* Get the type of this event.
* @return the event type.
*/
public String getEventType() {
return this.event.getEventType();
}
/**
* Get the time associated with the occurrence of this event.
* @return the event time.
*/
public OffsetDateTime getEventTime() {
return this.event.getEventTime();
}
/**
* Set the time associated with the event. Note that a default time has already been set when the event was
* constructed.
* @param time the time to set.
*
* @return the event itself.
*/
public EventGridEvent setEventTime(OffsetDateTime time) {
this.event.setEventTime(time);
return this;
}
/**
* Get the version of the data in the event. This can be used to specify versioning of event data schemas over time.
* @return the version of the event data.
*/
public String getDataVersion() {
return this.event.getDataVersion();
}
EventGridEvent(com.azure.messaging.eventgrid.implementation.models.EventGridEvent impl) {
this.event = impl;
}
com.azure.messaging.eventgrid.implementation.models.EventGridEvent toImpl() {
return this.event;
}
private static class JacksonSerializer implements JsonSerializer {
private final SerializerAdapter jacksonAdapter = JacksonAdapter.createDefaultSerializerAdapter();
@Override
public <T> T deserialize(InputStream stream, TypeReference<T> typeReference) {
try {
return jacksonAdapter.deserialize(stream, typeReference.getJavaType(), SerializerEncoding.JSON);
} catch (IOException e) {
throw LOGGER.logExceptionAsError(new UncheckedIOException(e));
}
}
@Override
public <T> Mono<T> deserializeAsync(InputStream stream, TypeReference<T> typeReference) {
return Mono.defer(() -> Mono.fromCallable(() -> deserialize(stream, typeReference)));
}
@Override
public void serialize(OutputStream stream, Object value) {
try {
jacksonAdapter.serialize(value, SerializerEncoding.JSON, stream);
} catch (IOException e) {
throw LOGGER.logExceptionAsError(new UncheckedIOException(e));
}
}
@Override
public Mono<Void> serializeAsync(OutputStream stream, Object value) {
return Mono.fromRunnable(() -> serialize(stream, value));
}
}
}