| /* |
| * 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.flink.streaming.kafka.test; |
| |
| import org.apache.flink.api.java.utils.ParameterTool; |
| import org.apache.flink.streaming.api.datastream.DataStream; |
| import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment; |
| import org.apache.flink.streaming.connectors.kafka.FlinkKafkaConsumer010; |
| import org.apache.flink.streaming.connectors.kafka.FlinkKafkaProducer010; |
| import org.apache.flink.streaming.kafka.test.base.CustomWatermarkExtractor; |
| import org.apache.flink.streaming.kafka.test.base.KafkaEvent; |
| import org.apache.flink.streaming.kafka.test.base.KafkaEventSchema; |
| import org.apache.flink.streaming.kafka.test.base.KafkaExampleUtil; |
| import org.apache.flink.streaming.kafka.test.base.RollingAdditionMapper; |
| |
| /** |
| * A simple example that shows how to read from and write to Kafka. This will read String messages |
| * from the input topic, parse them into a POJO type {@link KafkaEvent}, group by some key, and |
| * finally perform a rolling addition on each key for which the results are written back to another |
| * topic. |
| * |
| * <p>This example also demonstrates using a watermark assigner to generate per-partition watermarks |
| * directly in the Flink Kafka consumer. For demonstration purposes, it is assumed that the String |
| * messages are of formatted as a (word,frequency,timestamp) tuple. |
| * |
| * <p>Example usage: --input-topic test-input --output-topic test-output --bootstrap.servers |
| * localhost:9092 localhost:2181 --group.id myconsumer |
| */ |
| public class Kafka010Example { |
| |
| public static void main(String[] args) throws Exception { |
| // parse input arguments |
| final ParameterTool parameterTool = ParameterTool.fromArgs(args); |
| StreamExecutionEnvironment env = KafkaExampleUtil.prepareExecutionEnv(parameterTool); |
| |
| DataStream<KafkaEvent> input = |
| env.addSource( |
| new FlinkKafkaConsumer010<>( |
| parameterTool.getRequired("input-topic"), |
| new KafkaEventSchema(), |
| parameterTool.getProperties()) |
| .assignTimestampsAndWatermarks( |
| new CustomWatermarkExtractor())) |
| .keyBy("word") |
| .map(new RollingAdditionMapper()); |
| |
| input.addSink( |
| new FlinkKafkaProducer010<>( |
| parameterTool.getRequired("output-topic"), |
| new KafkaEventSchema(), |
| parameterTool.getProperties())); |
| |
| env.execute("Kafka 0.10 Example"); |
| } |
| } |