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.
   */
  
  // beam-playground:
  //   name: data-driven-trigger
  //   description: Data driven trigger example.
  //   multifile: false
  //   context_line: 48
  //   categories:
  //     - Quickstart
  //   complexity: ADVANCED
  //   tags:
  //     - hellobeam
  
  import org.apache.beam.model.pipeline.v1.RunnerApi;
  import org.apache.beam.sdk.Pipeline;
  import org.apache.beam.sdk.transforms.*;
  import org.apache.beam.sdk.options.PipelineOptions;
  import org.apache.beam.sdk.options.PipelineOptionsFactory;
  import org.apache.beam.sdk.transforms.Combine;
  import org.apache.beam.sdk.transforms.Count;
  import org.apache.beam.sdk.transforms.windowing.*;
  import org.apache.beam.sdk.values.KV;
  import org.apache.beam.sdk.values.PCollection;
  import org.joda.time.Duration;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  public class Task {
  
      private static final Logger LOG = LoggerFactory.getLogger(Task.class);
  
      public static void main(String[] args) {
          PipelineOptions options = PipelineOptionsFactory.fromArgs(args).create();
          Pipeline pipeline = Pipeline.create(options);
  
          PCollection<String> input = pipeline.apply(Create.of("first", "second"));
  
          Window<String> window = Window.into(FixedWindows.of(Duration.standardMinutes(5)));
  
          Trigger trigger = AfterPane.elementCountAtLeast(100);
  
          PCollection<String> windowed = input.apply(window.triggering(trigger).withAllowedLateness(Duration.ZERO).discardingFiredPanes());
  
          windowed.apply("Event time trigger", ParDo.of(new LogOutput<>("Result")));
  
          pipeline.run();
      }
  
      static class LogOutput<T> extends DoFn<T, T> {
  
          private String prefix;
  
          LogOutput() {
              this.prefix = "Processing element";
          }
  
          LogOutput(String prefix) {
              this.prefix = prefix;
          }
  
          @ProcessElement
          public void processElement(ProcessContext c) throws Exception {
              LOG.info(prefix + ": {}", c.element());
          }
      }
  }