org.springframework.kafka.listener.adapter.FilteringMessageListenerAdapter.java Source code

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Here is the source code for org.springframework.kafka.listener.adapter.FilteringMessageListenerAdapter.java

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/*
 * Copyright 2016-2019 the original author or authors.
 *
 * Licensed 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
 *
 *      https://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.springframework.kafka.listener.adapter;

import org.apache.kafka.clients.consumer.Consumer;
import org.apache.kafka.clients.consumer.ConsumerRecord;

import org.springframework.kafka.listener.AcknowledgingConsumerAwareMessageListener;
import org.springframework.kafka.listener.MessageListener;
import org.springframework.kafka.support.Acknowledgment;

/**
 * A {@link MessageListener} adapter that implements filter logic
 * via a {@link RecordFilterStrategy}.
 *
 * @param <K> the key type.
 * @param <V> the value type.
 *
 * @author Gary Russell
 *
 */
public class FilteringMessageListenerAdapter<K, V>
        extends AbstractFilteringMessageListener<K, V, MessageListener<K, V>>
        implements AcknowledgingConsumerAwareMessageListener<K, V> {

    private final boolean ackDiscarded;

    /**
     * Create an instance with the supplied strategy and delegate listener.
     * @param delegate the delegate.
     * @param recordFilterStrategy the filter.
     */
    public FilteringMessageListenerAdapter(MessageListener<K, V> delegate,
            RecordFilterStrategy<K, V> recordFilterStrategy) {
        super(delegate, recordFilterStrategy);
        this.ackDiscarded = false;
    }

    /**
     * Create an instance with the supplied strategy and delegate listener.
     * @param delegate the delegate.
     * @param recordFilterStrategy the filter.
     * @param ackDiscarded true to ack (commit offset for) discarded messages when the
     * listener is configured for manual acks.
     */
    public FilteringMessageListenerAdapter(MessageListener<K, V> delegate,
            RecordFilterStrategy<K, V> recordFilterStrategy, boolean ackDiscarded) {
        super(delegate, recordFilterStrategy);
        this.ackDiscarded = ackDiscarded;
    }

    @Override
    public void onMessage(ConsumerRecord<K, V> consumerRecord, Acknowledgment acknowledgment,
            Consumer<?, ?> consumer) {
        if (!filter(consumerRecord)) {
            switch (this.delegateType) {
            case ACKNOWLEDGING_CONSUMER_AWARE:
                this.delegate.onMessage(consumerRecord, acknowledgment, consumer);
                break;
            case ACKNOWLEDGING:
                this.delegate.onMessage(consumerRecord, acknowledgment);
                break;
            case CONSUMER_AWARE:
                this.delegate.onMessage(consumerRecord, consumer);
                break;
            case SIMPLE:
                this.delegate.onMessage(consumerRecord);
            }
        } else {
            ackFilteredIfNecessary(acknowledgment);
        }
    }

    private void ackFilteredIfNecessary(Acknowledgment acknowledgment) {
        switch (this.delegateType) {
        case ACKNOWLEDGING_CONSUMER_AWARE:
        case ACKNOWLEDGING:
            if (this.ackDiscarded && acknowledgment != null) {
                acknowledgment.acknowledge();
            }
            break;
        case CONSUMER_AWARE:
        case SIMPLE:
        }
    }

    /*
     * Since the container uses the delegate's type to determine which method to call, we
     * must implement them all.
     */

    @Override
    public void onMessage(ConsumerRecord<K, V> data) {
        onMessage(data, null, null);
    }

    @Override
    public void onMessage(ConsumerRecord<K, V> data, Acknowledgment acknowledgment) {
        onMessage(data, acknowledgment, null);
    }

    @Override
    public void onMessage(ConsumerRecord<K, V> data, Consumer<?, ?> consumer) {
        onMessage(data, null, consumer);
    }

}