Flink 入门编写(java)

这是Flink入门代码,较为简单

package com.heiheihei.flink;

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.operators.DataSource;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.util.Collector;

/**
 * @author 嘿嘿嘿1212
 * @version 1.0
 * @date 2020/3/31 16:26
 */
public class WordWithCount {
    public static void main(String[] args) throws Exception {
        //构建环境
        final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
        //通过字符串构建数据集
        DataSource<String> text = env.fromElements(
                "Who's there?",
                "I think I hear them Stand, ho! Who's there?"
        );
        //分割字符串,按照key进行分组,统计相同的key个数
        DataSet<Tuple2<String, Integer>> wordCounts = text
                .flatMap(new LineSplitter())
                .groupBy(0)//聚合
                .sum(1);//统计
        //打印
        wordCounts.print();

    }

    public static class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {
        @Override
        public void flatMap(String line, Collector<Tuple2<String, Integer>> collector) throws Exception {
            //根据空格进行切割
            for (String word : line.split(" ")) {
                collector.collect(new Tuple2<>(word, 1));
            }
        }
    }
}