content: /*
   * 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.beam.learning.katas.examples.wordcount;
  
  // beam-playground:
  //   name: WordCountKata
  //   description: Task from katas to create a pipeline that counts the number of words.
  //   multifile: false
  //   context_line: 50
  //   categories:
  //     - Combiners
  //   complexity: BASIC
  //   tags:
  //     - count
  //     - transforms
  //     - numbers
  
  import java.util.Arrays;
  import org.apache.beam.learning.katas.util.Log;
  import org.apache.beam.sdk.Pipeline;
  import org.apache.beam.sdk.options.PipelineOptions;
  import org.apache.beam.sdk.options.PipelineOptionsFactory;
  import org.apache.beam.sdk.transforms.Count;
  import org.apache.beam.sdk.transforms.Create;
  import org.apache.beam.sdk.transforms.DoFn;
  import org.apache.beam.sdk.transforms.FlatMapElements;
  import org.apache.beam.sdk.transforms.ParDo;
  import org.apache.beam.sdk.values.KV;
  import org.apache.beam.sdk.values.PCollection;
  import org.apache.beam.sdk.values.TypeDescriptors;
  
  public class Task {
  
    public static void main(String[] args) {
      String[] lines = {
          "apple orange grape banana apple banana",
          "banana orange banana papaya"
      };
  
      PipelineOptions options = PipelineOptionsFactory.fromArgs(args).create();
      Pipeline pipeline = Pipeline.create(options);
  
      PCollection<String> wordCounts =
          pipeline.apply(Create.of(Arrays.asList(lines)));
  
      PCollection<String> output = applyTransform(wordCounts);
  
      output.apply(Log.ofElements());
  
      pipeline.run();
    }
  
    static PCollection<String> applyTransform(PCollection<String> input) {
      return input
  
          .apply(FlatMapElements.into(TypeDescriptors.strings())
              .via(line -> Arrays.asList(line.split(" "))))
  
          .apply(Count.perElement())
  
          .apply(ParDo.of(new DoFn<KV<String, Long>, String>() {
  
            @ProcessElement
            public void processElement(
                @Element KV<String, Long> element, OutputReceiver<String> out) {
  
              out.output(element.getKey() + ":" + element.getValue());
            }
  
          }));
    }
  
  }