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.kafka.streams.test.wordcount;
  
  import org.apache.kafka.streams.KeyValue;
  import org.apache.kafka.streams.kstream.Windowed;
  import org.apache.kafka.streams.processor.PunctuationType;
  import org.apache.kafka.streams.processor.api.Processor;
  import org.apache.kafka.streams.processor.api.ProcessorContext;
  import org.apache.kafka.streams.processor.api.ProcessorSupplier;
  import org.apache.kafka.streams.processor.api.Record;
  import org.apache.kafka.streams.state.KeyValueIterator;
  import org.apache.kafka.streams.state.WindowStore;
  
  import java.time.Duration;
  import java.util.Locale;
  
  public final class WindowedWordCountProcessorSupplier implements ProcessorSupplier<String, String, String, String> {
  
      @Override
      public Processor<String, String, String, String> get() {
          return new Processor<String, String, String, String>() {
              private WindowStore<String, Integer> windowStore;
  
              @Override
              public void init(final ProcessorContext<String, String> context) {
                  context.schedule(Duration.ofSeconds(1), PunctuationType.STREAM_TIME, timestamp -> {
                      try (final KeyValueIterator<Windowed<String>, Integer> iter = windowStore.all()) {
                          while (iter.hasNext()) {
                              final KeyValue<Windowed<String>, Integer> entry = iter.next();
                              context.forward(new Record<>(entry.key.toString(), entry.value.toString(), timestamp));
                          }
                      }
                  });
                  windowStore = context.getStateStore("WindowedCounts");
              }
  
              @Override
              public void process(final Record<String, String> record) {
                  final String[] words = record.value().toLowerCase(Locale.getDefault()).split(" ");
                  final long timestamp = record.timestamp();
  
                  // calculate the window as every 100 ms
                  // Note this has to be aligned with the configuration for the window store you register separately
                  final long windowStart = timestamp / 100 * 100;
  
                  for (final String word : words) {
                      final Integer oldValue = windowStore.fetch(word, windowStart);
  
                      if (oldValue == null) {
                          windowStore.put(word, 1, windowStart);
                      } else {
                          windowStore.put(word, oldValue + 1, windowStart);
                      }
                  }
              }
          };
      }
  }
  