Flink实现WordCount

import org.apache.flink.api.common.functions.FlatMapFunction; import org.apache.flink.api.java.DataSet; import org.apache.flink.api.java.ExecutionEnvironment; import org.apache.flink.api.java.tuple.Tuple2; import org.apache.flink.util.Collector; public class WordCount { public static void main(String[] args) throws Exception { final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment(); DataSet<String> text = env.fromElements("To be, or not to be,--that is the question:--", "Whether 'tis nobler in the mind to suffer", "The slings and arrows of outrageous fortune", "Or to take arms against a sea of troubles,"); DataSet<Tuple2<String, Integer>> counts = text.flatMap(new FlatMapFunction<String, Tuple2<String, Integer>>() { @Override public void flatMap(String s, Collector<Tuple2<String, Integer>> collector) throws Exception { String[] tokens = s.toLowerCase().split("\\s+"); for (String token : tokens) { if (token.length() > 0) { collector.collect(new Tuple2<String, Integer>(token, 1)); } } } }).groupBy(0).sum(1); counts.print(); } }