com.google.cloud.pubsub.PublisherSamples.java Source code

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Here is the source code for com.google.cloud.pubsub.PublisherSamples.java

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/*
 * Copyright 2016 Google Inc. All Rights Reserved.
 *
 * 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 com.google.cloud.pubsub;

import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.protobuf.ByteString;
import com.google.pubsub.v1.PubsubMessage;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import org.joda.time.Duration;

/**
 * Some sensible samples that demonstrate how to use the {@link Publisher Cloud Pub/Sub Publisher}.
 */
public class PublisherSamples {
    private final String topic;
    private long startTimeMs;

    private PublisherSamples(String topic) {
        this.topic = topic;
    }

    @SuppressWarnings("unchecked")
    public void simplePublisher() throws Exception {
        Publisher publisher = Publisher.Builder.newBuilder(topic).setMaxBatchDuration(new Duration(500))
                .setMaxBatchBytes(1 * 1000 * 1000).setRequestTimeout(Duration.standardSeconds(60)).build();

        startTimeMs = System.currentTimeMillis();
        System.out.println("Publishing messages at " + startTimeMs + " ms.");

        List<ListenableFuture<String>> results = new ArrayList<>();

        for (int i = 0; i < 1000; ++i) {
            PubsubMessage message = PubsubMessage.newBuilder().setData(ByteString.copyFromUtf8("" + i)).build();
            results.add(publisher.publish(message));
        }

        System.out.println("Batched messages in " + (System.currentTimeMillis() - startTimeMs) + " ms.");

        handleResults(results);

        publisher.shutdown();
    }

    public void customBatchingPublisher() throws Exception {
        Publisher publisher = Publisher.Builder.newBuilder(topic).setMaxBatchMessages(10).build();

        List<ListenableFuture<String>> results = new ArrayList<>();
        PubsubMessage message = PubsubMessage.newBuilder()
                .setData(ByteString.copyFromUtf8(String.format("my default batch options message"))).build();
        // Uses the default batching options.
        results.add(publisher.publish(message));

        handleResults(results);
        publisher.shutdown();
    }

    private void flowControlledPublisher() throws Exception {
        Publisher publisher = Publisher.Builder.newBuilder(topic).setMaxOutstandingBytes(10 * 1000 * 1000) // 10 MB
                .build();

        List<ListenableFuture<String>> results = new ArrayList<>();
        PubsubMessage message = PubsubMessage.newBuilder()
                .setData(ByteString.copyFromUtf8(String.format("my default batch options message"))).build();
        // Uses the default batching options.
        results.add(publisher.publish(message));

        handleResults(results);
        publisher.shutdown();
    }

    private void handleResults(List<ListenableFuture<String>> results) {
        List<String> messageIds = new ArrayList<>(results.size());
        Futures.whenAllComplete(results).call(new Callable<Void>() {
            @Override
            public Void call() throws Exception {
                long endTime = System.currentTimeMillis();
                System.out.printf("Finished publishing messages at %d ms, elapsed %d ms\n", endTime,
                        endTime - startTimeMs);
                int okCount = 0;
                int failCount = 0;
                for (ListenableFuture<String> result : results) {
                    try {
                        messageIds.add(result.get());
                        ++okCount;
                    } catch (Exception e) {
                        e.printStackTrace();
                        ++failCount;
                    }
                }
                System.out.println("Total messages published OK: " + okCount);
                System.out.println("Total messages failed: " + failCount);

                return null;
            }
        });
    }

    public static void main(String[] args) throws Exception {
        if (args.length == 0) {
            System.out.println("You must specify a topic as a parameter.");
            System.exit(1);
            return;
        }

        PublisherSamples samples = new PublisherSamples(args[0]);
        samples.simplePublisher();
        samples.customBatchingPublisher();
        samples.flowControlledPublisher();
    }
}