org.apache.pulsar.client.api.MessageListener Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.pulsar.client.api;
import java.io.Serializable;
import org.apache.pulsar.common.classification.InterfaceAudience;
import org.apache.pulsar.common.classification.InterfaceStability;
/**
* A listener that will be called in order for every message received.
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public interface MessageListener extends Serializable {
/**
* This method is called whenever a new message is received.
*
* Messages are guaranteed to be delivered in order and from the same thread for a single consumer
*
*
This method will only be called once for each message, unless either application or broker crashes.
*
*
Application is responsible for acking message by calling any of consumer acknowledgement methods.
*
*
Application is responsible of handling any exception that could be thrown while processing the message.
*
* @param consumer
* the consumer that received the message
* @param msg
* the message object
*/
void received(Consumer consumer, Message msg);
/**
* Get the notification when a topic is terminated.
*
* @param consumer
* the Consumer object associated with the terminated topic
*/
default void reachedEndOfTopic(Consumer consumer) {
// By default ignore the notification
}
}