package cn.lihm.examples.streaming;

import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.api.java.utils.ParameterTool;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.util.Collector;

/**
 * @author lihm
 * @date 2019-07-23 16:18
 * @description TODO
 */

public class SocketTextStreamWordCount {
    public static void main(String[] args) throws Exception {
        // the port to connect to
        final String hostname;
        final int port;
        try {
            final ParameterTool params = ParameterTool.fromArgs(args);
            port = params.getInt("port");
            hostname = params.get("hostname");
        } catch (Exception e) {
            System.err.println("USAGE: Please run 'SocketWindowWordCount --hostname <hostname> --port <port>'");
            return;
        }
        // set up the streaming execution environment
        final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

        // 获取数据
        DataStreamSource<String> stream = env.socketTextStream(hostname, port);

        // 计数
        SingleOutputStreamOperator<Tuple2<String, Integer>> sum = stream.flatMap(new LineSplitter())
                .keyBy(0)
                .sum(1);

        sum.print();

        env.execute("Java WordCount from SocketTextStream Example");
    }

    public static final class LineSplitter implements FlatMapFunction<String, Tuple2<String, Integer>> {
        @Override
        public void flatMap(String s, Collector<Tuple2<String, Integer>> collector) {
            String[] tokens = s.toLowerCase().split("\\W+");

            for (String token: tokens) {
                if (token.length() > 0) {
                    collector.collect(new Tuple2<String, Integer>(token, 1));
                }
            }
        }
    }
}