当前位置：首页 > article >正文

Flink有界流实现(1)

article 2024/11/15 9:50:44

flink实现有界流需要使用StreamExecutionEnvironment类，并且最后需要使用env.execute() 方法，有界和无界的算子有时候会有不同的
复杂的写法

package org.example.test;
import org.apache.flink.api.java.functions.KeySelector;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.datastream.KeyedStream;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.functions.ProcessFunction;
import org.apache.flink.util.Collector;
/**
 * DataSet API使用
 */
public class WordCountDataStream {

    public static void main(String[] args) throws Exception {
        //TODO 1、获取流的类
        final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

        //TODO 2、读取文件
//        DataStreamSource<String> stringDataStreamSource = env.readTextFile("input/test.txt");

        DataStreamSource<String> stringDataStreamSource = env.socketTextStream("localhost", 9000, "\n");

        //TODO 3 ETL
        //TODO 3.1 转换成二元数组,简单ETL的过程
        SingleOutputStreamOperator<Tuple2<String, Integer>> process = stringDataStreamSource.process(new ProcessFunction<String, Tuple2<String, Integer>>() {
            @Override
            public void processElement(String value, ProcessFunction<String, Tuple2<String, Integer>>.Context ctx, Collector<Tuple2<String, Integer>> out) throws Exception {
                String[] words = value.split(" ");
                for (String word : words) {
                    Tuple2<String, Integer> tuple2 = Tuple2.of(word, 1);
                    out.collect(tuple2);
                }
            }
        });

        //TODO 3.1 分组
        KeyedStream<Tuple2<String, Integer>, String> tuple2StringKeyedStream = process.keyBy(new KeySelector<Tuple2<String, Integer>, String>() {

            @Override
            public String getKey(Tuple2<String, Integer> value) throws Exception {
                return value.f0;
            }
        });

        //TODO 3.2 聚合计算
        SingleOutputStreamOperator<Tuple2<String, Integer>> sum = tuple2StringKeyedStream.sum(1);

        //TODO 4、打印
        sum.print();

        //TODO 5、无界流需要这个不断执行的方法
        env.execute();
    }
}