/*
* 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.storm.exclamation;
import org.apache.storm.utils.Utils;
import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.java.typeutils.TypeExtractor;
import org.apache.flink.examples.java.wordcount.util.WordCountData;
import org.apache.flink.storm.exclamation.operators.ExclamationBolt;
import org.apache.flink.storm.util.StormConfig;
import org.apache.flink.storm.wrappers.BoltWrapper;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
/**
* Implements the "Exclamation" program that attaches 3+x exclamation marks to every line of a text files in a streaming
* fashion. The program is constructed as a regular {@link org.apache.storm.generated.StormTopology}.
* <p>
* The input is a plain text file with lines separated by newline characters.
* <p>
* Usage:
* <code>ExclamationWithmBolt <text path> <result path> <number of exclamation marks></code><br>
* If no parameters are provided, the program is run with default data from {@link WordCountData} with x=2.
* <p>
* This example shows how to:
* <ul>
* <li>use a Bolt within a Flink Streaming program</li>
* <li>how to configure a Bolt using StormConfig</li>
* </ul>
*/
public class ExclamationWithBolt {
// *************************************************************************
// PROGRAM
// *************************************************************************
public static void main(final String[] args) throws Exception {
if (!parseParameters(args)) {
return;
}
// set up the execution environment
final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
// set Storm configuration
StormConfig config = new StormConfig();
config.put(ExclamationBolt.EXCLAMATION_COUNT, new Integer(exclamationNum));
env.getConfig().setGlobalJobParameters(config);
// get input data
final DataStream<String> text = getTextDataStream(env);
final DataStream<String> exclaimed = text
.transform("StormBoltTokenizer",
TypeExtractor.getForObject(""),
new BoltWrapper<String, String>(new ExclamationBolt(),
new String[] { Utils.DEFAULT_STREAM_ID }))
.map(new ExclamationMap());
// emit result
if (fileOutput) {
exclaimed.writeAsText(outputPath);
} else {
exclaimed.print();
}
// execute program
env.execute("Streaming WordCount with bolt tokenizer");
}
// *************************************************************************
// USER FUNCTIONS
// *************************************************************************
private static class ExclamationMap implements MapFunction<String, String> {
private static final long serialVersionUID = 4614754344067170619L;
@Override
public String map(String value) throws Exception {
return value + "!!!";
}
}
// *************************************************************************
// UTIL METHODS
// *************************************************************************
private static boolean fileOutput = false;
private static String textPath;
private static String outputPath;
private static int exclamationNum = 2;
private static boolean parseParameters(final String[] args) {
if (args.length > 0) {
// parse input arguments
fileOutput = true;
if (args.length == 3) {
textPath = args[0];
outputPath = args[1];
exclamationNum = Integer.parseInt(args[2]);
} else {
System.err.println("Usage: ExclamationWithBolt <text path> <result path> <number of exclamation marks>");
return false;
}
} else {
System.out.println("Executing ExclamationWithBolt example with built-in default data");
System.out.println(" Provide parameters to read input data from a file");
System.out.println(" Usage: ExclamationWithBolt <text path> <result path> <number of exclamation marks>");
}
return true;
}
private static DataStream<String> getTextDataStream(final StreamExecutionEnvironment env) {
if (fileOutput) {
// read the text file from given input path
return env.readTextFile(textPath);
}
return env.fromElements(WordCountData.WORDS);
}
}