Java tutorial
/* * 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.triggers.earlytriggers; 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.Combine; import org.apache.beam.sdk.transforms.Count; import org.apache.beam.sdk.transforms.windowing.AfterProcessingTime; import org.apache.beam.sdk.transforms.windowing.AfterWatermark; import org.apache.beam.sdk.transforms.windowing.FixedWindows; import org.apache.beam.sdk.transforms.windowing.Window; import org.apache.beam.sdk.values.PCollection; import org.joda.time.Duration; public class Task { public static void main(String[] args) { PipelineOptions options = PipelineOptionsFactory.fromArgs(args).create(); Pipeline pipeline = Pipeline.create(options); PCollection<String> events = pipeline.apply(GenerateEvent.everySecond()); PCollection<Long> output = applyTransform(events); output.apply(Log.ofElements()); pipeline.run(); } static PCollection<Long> applyTransform(PCollection<String> events) { return events .apply(Window.<String>into(FixedWindows.of(Duration.standardDays(1))) .triggering(AfterWatermark.pastEndOfWindow() .withEarlyFirings(AfterProcessingTime.pastFirstElementInPane())) .withAllowedLateness(Duration.ZERO).discardingFiredPanes()) .apply(Combine.globally(Count.<String>combineFn()).withoutDefaults()); } }