org.apache.apex.malhar.stream.sample.ApplicationWithStreamAPI.java Source code

Introduction

Here is the source code for org.apache.apex.malhar.stream.sample.ApplicationWithStreamAPI.java

Source

/**
 * 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;

import java.util.Arrays;

import org.joda.time.Duration;

import org.apache.apex.malhar.lib.function.Function;
import org.apache.apex.malhar.lib.util.KeyValPair;
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.stream.api.ApexStream;
import org.apache.apex.malhar.stream.api.impl.StreamFactory;
import org.apache.hadoop.conf.Configuration;

import com.datatorrent.api.DAG;
import com.datatorrent.api.StreamingApplication;
import com.datatorrent.api.annotation.ApplicationAnnotation;

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

/**
 * An application example with stream api
 */
@ApplicationAnnotation(name = "WordCountStreamingApiDemo")
public class ApplicationWithStreamAPI implements StreamingApplication {

    @Override
    public void populateDAG(DAG dag, Configuration configuration) {
        String localFolder = "./src/test/resources/data";
        ApexStream<String> stream = StreamFactory.fromFolder(localFolder)
                .flatMap(new Function.FlatMapFunction<String, String>() {
                    @Override
                    public Iterable<String> f(String input) {
                        return Arrays.asList(input.split("[\\p{Punct}\\s]+"));
                    }
                });
        stream.print(name("WordOutput"));
        stream.window(new WindowOption.GlobalWindow(),
                new TriggerOption().withEarlyFiringsAtEvery(Duration.millis(1000)).accumulatingFiredPanes())
                .countByKey(new Function.ToKeyValue<String, String, Long>() {
                    @Override
                    public Tuple<KeyValPair<String, Long>> f(String input) {
                        return new Tuple.PlainTuple(new KeyValPair<>(input, 1L));
                    }
                }).print(name("WCOutput"));
        stream.populateDag(dag);

    }
}