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/*
* 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.spark.streaming.examples;
import com.google.common.collect.Lists;
import scala.Tuple2;
import org.apache.spark.api.java.function.FlatMapFunction;
import org.apache.spark.api.java.function.Function2;
import org.apache.spark.api.java.function.PairFunction;
import org.apache.spark.streaming.Duration;
import org.apache.spark.streaming.api.java.JavaDStream;
import org.apache.spark.streaming.api.java.JavaPairDStream;
import org.apache.spark.streaming.api.java.JavaStreamingContext;
import java.util.regex.Pattern;
/**
* Counts words in UTF8 encoded, '\n' delimited text received from the network every second.
* Usage: NetworkWordCount <master> <hostname> <port>
* <master> is the Spark master URL. In local mode, <master> should be 'local[n]' with n > 1.
* <hostname> and <port> describe the TCP server that Spark Streaming would connect to receive data.
*
* To run this on your local machine, you need to first run a Netcat server
* `$ nc -lk 9999`
* and then run the example
* `$ ./run org.apache.spark.streaming.examples.JavaNetworkWordCount local[2] localhost 9999`
*/
public final class JavaNetworkWordCount {
private static final Pattern SPACE = Pattern.compile(" ");
private JavaNetworkWordCount() {
}
public static void main(String[] args) {
if (args.length < 3) {
System.err.println("Usage: JavaNetworkWordCount <master> <hostname> <port>\n" +
"In local mode, <master> should be 'local[n]' with n > 1");
System.exit(1);
}
StreamingExamples.setStreamingLogLevels();
// Create the context with a 1 second batch size
JavaStreamingContext ssc = new JavaStreamingContext(args[0], "JavaNetworkWordCount",
new Duration(1000), System.getenv("SPARK_HOME"),
JavaStreamingContext.jarOfClass(JavaNetworkWordCount.class));
// Create a NetworkInputDStream on target ip:port and count the
// words in input stream of \n delimited text (eg. generated by 'nc')
JavaDStream<String> lines = ssc.socketTextStream(args[1], Integer.parseInt(args[2]));
JavaDStream<String> words = lines.flatMap(new FlatMapFunction<String, String>() {
@Override
public Iterable<String> call(String x) {
return Lists.newArrayList(SPACE.split(x));
}
});
JavaPairDStream<String, Integer> wordCounts = words.mapToPair(
new PairFunction<String, String, Integer>() {
@Override
public Tuple2<String, Integer> call(String s) {
return new Tuple2<String, Integer>(s, 1);
}
}).reduceByKey(new Function2<Integer, Integer, Integer>() {
@Override
public Integer call(Integer i1, Integer i2) {
return i1 + i2;
}
});
wordCounts.print();
ssc.start();
ssc.awaitTermination();
}
}
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