org.apache.apex.malhar.stream.sample.cookbook.DeDupExample.java Source code

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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.apex.malhar.stream.sample.cookbook;

import java.util.Arrays;
import java.util.List;

import org.joda.time.Duration;

import org.apache.apex.malhar.lib.function.Function;
import org.apache.apex.malhar.lib.window.TriggerOption;
import org.apache.apex.malhar.lib.window.Tuple;
import org.apache.apex.malhar.lib.window.WindowOption;
import org.apache.apex.malhar.lib.window.accumulation.RemoveDuplicates;
import org.apache.apex.malhar.stream.api.ApexStream;
import org.apache.apex.malhar.stream.api.impl.StreamFactory;
import org.apache.hadoop.conf.Configuration;

import com.datatorrent.api.Context;
import com.datatorrent.api.DAG;
import com.datatorrent.api.DefaultInputPort;
import com.datatorrent.api.StreamingApplication;
import com.datatorrent.api.annotation.ApplicationAnnotation;
import com.datatorrent.common.util.BaseOperator;

import static org.apache.apex.malhar.stream.api.Option.Options.name;

/**
 * Beam DeDupExample.
 *
 * @since 3.5.0
 */
@ApplicationAnnotation(name = "DeDupExample")
public class DeDupExample implements StreamingApplication {

    public static class Collector extends BaseOperator {
        private static Tuple.WindowedTuple<List<String>> result;
        private static boolean done = false;

        public static Tuple.WindowedTuple<List<String>> getResult() {
            return result;
        }

        public static boolean isDone() {
            return done;
        }

        @Override
        public void setup(Context.OperatorContext context) {
            super.setup(context);
            result = new Tuple.WindowedTuple<>();
            done = false;
        }

        public transient DefaultInputPort<Tuple.WindowedTuple<List<String>>> input = new DefaultInputPort<Tuple.WindowedTuple<List<String>>>() {
            @Override
            public void process(Tuple.WindowedTuple<List<String>> tuple) {
                result = tuple;
                if (result.getValue().contains("bye")) {
                    done = true;
                }
            }
        };
    }

    @Override
    public void populateDAG(DAG dag, Configuration conf) {
        Collector collector = new Collector();

        // Create a stream that reads from files in a local folder and output lines one by one to downstream.
        ApexStream<String> stream = StreamFactory.fromFolder("./src/test/resources/wordcount", name("textInput"))

                // Extract all the words from the input line of text.
                .flatMap(new Function.FlatMapFunction<String, String>() {
                    @Override
                    public Iterable<String> f(String input) {
                        return Arrays.asList(input.split("[\\p{Punct}\\s]+"));
                    }
                }, name("ExtractWords"))

                // Change the words to lower case, also shutdown the app when the word "bye" is detected.
                .map(new Function.MapFunction<String, String>() {
                    @Override
                    public String f(String input) {
                        return input.toLowerCase();
                    }
                }, name("ToLowerCase"));

        // Apply window and trigger option.
        stream.window(new WindowOption.GlobalWindow(),
                new TriggerOption().accumulatingFiredPanes().withEarlyFiringsAtEvery(Duration.standardSeconds(1)))

                // Remove the duplicate words and print out the result.
                .accumulate(new RemoveDuplicates<String>(), name("RemoveDuplicates")).print(name("console"))
                .endWith(collector, collector.input).populateDag(dag);
    }
}