org.springframework.cloud.stream.binder.pubsub.PubSubMessageListener.java Source code

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Here is the source code for org.springframework.cloud.stream.binder.pubsub.PubSubMessageListener.java

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/*
 *  Copyright 2016 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
 *
 *       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.springframework.cloud.stream.binder.pubsub;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import org.springframework.cloud.stream.binder.pubsub.support.PubSubBinder;
import org.springframework.integration.endpoint.MessageProducerSupport;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.cloud.pubsub.PubSub;
import com.google.cloud.pubsub.Subscription;

/**
 * @author Vinicius Carvalho
 */
public class PubSubMessageListener extends MessageProducerSupport {

    private ObjectMapper mapper;
    private PubSubResourceManager resourceManager;
    private Subscription subscription;
    private PubSub.MessageConsumer messageConsumer;

    public PubSubMessageListener(PubSubResourceManager resourceManager, Subscription subscription) {
        this.resourceManager = resourceManager;
        this.mapper = new ObjectMapper();
        this.subscription = subscription;
    }

    @Override
    protected void doStart() {
        messageConsumer = subscription.pullAsync(message -> {
            sendMessage(getMessageBuilderFactory().withPayload(message.payload().toByteArray())
                    .copyHeaders(decodeAttributes(message.attributes())).build());
        });
    }

    private Map<String, Object> decodeAttributes(Map<String, String> attributes) {
        Map<String, Object> headers = new HashMap<>();
        if (attributes.get(PubSubBinder.SCST_HEADERS) != null) {
            try {
                headers.putAll(mapper.readValue(attributes.get(PubSubBinder.SCST_HEADERS), Map.class));
            } catch (IOException e) {
                logger.error("Could not deserialize SCST_HEADERS");
            }

        }
        return headers;
    }

    @Override
    protected void doStop() {
        try {
            messageConsumer.close();
        } catch (Exception e) {
            logger.error("Could not close pubsub message consumer");
        }
    }
}