Flink-批处理wordcount


public class wordcount {

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

        ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

        String inputPath = "D:\\IDEAWorkspace\\2017.3\\bigData\\Flink\\src\\main\\resources\\hello.txt";

        DataSet dataSource = env.readTextFile(inputPath);

        //对一批数据进行转换操作
        DataSet> result = dataSource.flatMap(new FlatMapFunction>() {
            @Override
            public void flatMap(String s, Collector> collector) throws Exception {

                String[] words = s.split(" ", -1);
                for (String word : words) {
                    collector.collect(new Tuple2<>(word, 1));
                }
            }
        })
        //已经有一批数据了,所以用groupBy进行分组        
        .groupBy(0)//根据元组的第一位分组
        .sum(1);//对元组的第二位进行求和

        result.print();

    }

}