org.apache.samza.sql.samples.system.OrdersStreamSystemFactory.java Source code

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Here is the source code for org.apache.samza.sql.samples.system.OrdersStreamSystemFactory.java

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/*
 * 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.samza.sql.samples.system;

import com.google.common.io.Resources;
import org.apache.avro.Schema;
import org.apache.avro.generic.GenericRecordBuilder;
import org.apache.samza.Partition;
import org.apache.samza.SamzaException;
import org.apache.samza.config.Config;
import org.apache.samza.metrics.MetricsRegistry;
import org.apache.samza.system.*;
import org.apache.samza.util.BlockingEnvelopeMap;
import org.apache.samza.util.SinglePartitionWithoutOffsetsSystemAdmin;

import java.io.IOException;
import java.nio.charset.Charset;
import java.util.Random;
import java.util.concurrent.atomic.AtomicInteger;

public class OrdersStreamSystemFactory implements SystemFactory {

    private final AtomicInteger orderId = new AtomicInteger(0);
    private static final Integer[] productIds = new Integer[] { 10, 34, 56, 78, 23, 34, 11, 15, 16, 18 };
    private final Random rand = new Random(System.currentTimeMillis());
    private final AtomicInteger offset = new AtomicInteger(0);

    private static String loadOrdersSchema() throws IOException {
        return Resources.toString(OrdersStreamSystemFactory.class.getResource("/orders_avro.avsc"),
                Charset.defaultCharset());
    }

    @Override
    public SystemConsumer getConsumer(final String systemName, Config config, MetricsRegistry registry) {
        String ordersSchemaStr = null;
        try {
            ordersSchemaStr = loadOrdersSchema();
        } catch (IOException e) {
            throw new SamzaException("Cannot load orders schema.", e);
        }

        final Schema ordersSchema = new Schema.Parser().parse(ordersSchemaStr);

        final SystemStreamPartition streamPartition = new SystemStreamPartition(systemName, "orders",
                new Partition(0));
        return new BlockingEnvelopeMap() {
            @Override
            public void start() {
                while (true) {
                    GenericRecordBuilder recordBuilder = new GenericRecordBuilder(ordersSchema);
                    int productId = productIds[rand.nextInt(10)];
                    recordBuilder.set("orderId", orderId.getAndIncrement());
                    recordBuilder.set("productId", productId);
                    recordBuilder.set("units", rand.nextInt(100));
                    recordBuilder.set("rowtime", System.currentTimeMillis());
                    try {
                        put(streamPartition, new IncomingMessageEnvelope(streamPartition,
                                String.valueOf(offset.getAndIncrement()), productId, recordBuilder.build()));
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }

                    try {
                        Thread.sleep(rand.nextInt(1000));
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }

            @Override
            public void stop() {

            }
        };
    }

    @Override
    public SystemProducer getProducer(String systemName, Config config, MetricsRegistry registry) {
        throw new SamzaException("You can't produce to the order generation system");
    }

    @Override
    public SystemAdmin getAdmin(String systemName, Config config) {
        return new SinglePartitionWithoutOffsetsSystemAdmin();
    }
}