Flink, 大数据

flink-17 合流

union

package com.learn.flink.combine;

import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;

public class UnionDemo {
    public static void main(String[] args) throws Exception {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        env.setParallelism(1);

        DataStreamSource<Integer> source1 = env.fromElements(1, 2, 3);
        DataStreamSource<Integer> source2 = env.fromElements(11, 22, 33);
        DataStreamSource<String> source3 = env.fromElements("111", "222", "333");

//        DataStream<Integer> union = source1.union(source2).union(source3.map(Integer::parseInt));
        DataStream<Integer> union = source1.union(source2, source3.map(Integer::parseInt));
        union.print();

        env.execute();
    }
}
  • 要求流的数据类型必须一致
  • 可以一次性union多个流

connect

package com.learn.flink.combine;

import org.apache.flink.streaming.api.datastream.ConnectedStreams;
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.streaming.api.functions.co.CoMapFunction;

public class ConnectDemo {
    public static void main(String[] args) throws Exception {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        env.setParallelism(1);

        DataStreamSource<Integer> source1 = env.fromElements(1, 2, 3);
        DataStreamSource<String> source2 = env.fromElements("111", "222", "333");

        ConnectedStreams<Integer, String> connect = source1.connect(source2);

        SingleOutputStreamOperator<String> result = connect.map(new CoMapFunction<Integer, String, String>() {
            @Override
            public String map1(Integer value) throws Exception {
                return value.toString();
            }

            @Override
            public String map2(String value) throws Exception {
                return value;
            }
        });

        result.print();

        env.execute();
    }
}
  • connect只能连接1条流
  • connectStream后续操作需要对两个流单独处理,同一类型输出
    • map、flatMap、process

inner join效果

package com.learn.flink.combine;

import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.api.java.tuple.Tuple3;
import org.apache.flink.streaming.api.datastream.ConnectedStreams;
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.streaming.api.functions.co.CoProcessFunction;
import org.apache.flink.util.Collector;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class ConnectKeybyDemo {
    public static void main(String[] args) throws Exception {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        env.setParallelism(2);

        DataStreamSource<Tuple2<Integer, String>> source1 = env.fromElements(
                Tuple2.of(1, "a1"),
                Tuple2.of(1, "a2"),
                Tuple2.of(2, "b"),
                Tuple2.of(3, "c")
        );

        DataStreamSource<Tuple3<Integer, String, Integer>> source2 = env.fromElements(
                Tuple3.of(1, "aa1", 1),
                Tuple3.of(1, "aa2", 2),
                Tuple3.of(2, "bb", 1),
                Tuple3.of(3, "cc", 1)
        );

        ConnectedStreams<Tuple2<Integer, String>, Tuple3<Integer, String, Integer>> connect = source1.connect(source2);

        // 多并行度下,需要根据条件进行keyby,才能保证key相同的数据到一起才能匹配上
        ConnectedStreams<Tuple2<Integer, String>, Tuple3<Integer, String, Integer>> connectKeyBy = connect.keyBy(s1 -> s1.f0, s2 -> s2.f0);

        /*
        实现互相匹配的效果:两条流,不一定谁的流的数据先来
        1、每条流,有数据来,存到一个变量中
            hashmap
            =》key = id 第一个字段值
            =》value=List<数据>
        2、每条流有数据来的时候,除了存变量中,不知道对方是否有匹配的数据,要去另一条流存的变量中 查找是否有匹配上的
         */
        SingleOutputStreamOperator<String> process = connectKeyBy.process(new CoProcessFunction<Tuple2<Integer, String>, Tuple3<Integer, String, Integer>, String>() {
            // 每条流都一个 定义hashmap用来存储数据
            Map<Integer, List<Tuple2<Integer, String>>> s1Cache = new HashMap<>();
            Map<Integer, List<Tuple3<Integer, String, Integer>>> s2Cache = new HashMap<>();

            /**
             * 第一条流的处理逻辑
             * @param value 第一条流的数据
             * @param ctx 上下文
             * @param out 采集器
             */
            @Override
            public void processElement1(Tuple2<Integer, String> value, CoProcessFunction<Tuple2<Integer, String>, Tuple3<Integer, String, Integer>, String>.Context ctx, Collector<String> out) throws Exception {
                Integer id = value.f0;
                // TODO s1的数据来了,就存到变量中
                if (!s1Cache.containsKey(id)) {
                    // 如果key不存在,说明是该key的第一条数据,初始化,put进map中
                    List<Tuple2<Integer, String>> s1Values = new ArrayList<>();
                    s1Values.add(value);
                    s1Cache.put(id, s1Values);
                } else {
                    // key存在,直接添加到value的list中
                    s1Cache.get(id).add(value);
                }

                // TODO 去s2Cache中查找是否有id能匹配上的, 匹配上就输出
                if (s2Cache.containsKey(id)) {
                    for (Tuple3<Integer, String, Integer> s2Element : s2Cache.get(id)) {
                        out.collect("s1:" + value + "<=====>" + "s2:" + s2Element);
                    }
                }
            }

            /**
             * 第二条流的处理逻辑
             * @param value 第一条流的数据
             * @param ctx 上下文
             * @param out 采集器
             */
            @Override
            public void processElement2(Tuple3<Integer, String, Integer> value, CoProcessFunction<Tuple2<Integer, String>, Tuple3<Integer, String, Integer>, String>.Context ctx, Collector<String> out) throws Exception {
                Integer id = value.f0;
                // TODO s2的数据来了,就存到变量中
                if (!s2Cache.containsKey(id)) {
                    // 如果key不存在,说明是该key的第一条数据,初始化,put进map中
                    List<Tuple3<Integer, String, Integer>> s2Values = new ArrayList<>();
                    s2Values.add(value);
                    s2Cache.put(id, s2Values);
                } else {
                    // key存在,直接添加到value的list中
                    s2Cache.get(id).add(value);
                }

                // TODO 去s2Cache中查找是否有id能匹配上的, 匹配上就输出
                if (s1Cache.containsKey(id)) {
                    for (Tuple2<Integer, String> s1Element : s1Cache.get(id)) {
                        out.collect("s1:" + s1Element + "<=====>" + "s2:" + value);
                    }
                }
            }
        });

        process.print();

        env.execute();
    }
}

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