第一个Flink程序 词频统计

• maven创建 Flink 应用程序，通过端口获取实时输入的字符串，利用Flink统计单词频率并打印出来

public static void main(String[] args) throws Exception {

    StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
    DataStream<Tuple2<String, Integer>> dataStream = env
            .socketTextStream("localhost", 9999)
            .flatMap(new Splitter())
            .keyBy(0)
            .timeWindow(Time.seconds(5))
            .sum(1);

    dataStream.print();

    env.execute("Window WordCount");
}

public static class Splitter implements FlatMapFunction<String, Tuple2<String, Integer>> {
    @Override
    public void flatMap(String sentence, Collector<Tuple2<String, Integer>> out) throws Exception {
        for (String word: sentence.split(" ")) {
            out.collect(new Tuple2<String, Integer>(word, 1));
        }
    }
}

necat 操作命令

linux
nc -lk 8080

wwindow 
nc -i -p 8080