Flink 系例 之 FlatMap

Flink 系例 之 FlatMap

FlatMap算子：将数据流一行按逻辑或规则拆分成0行或多行输出

示例环境

java.version: 1.8.x
flink.version: 1.11.1

示例数据源（项目码云下载）

Flink 系例 之 搭建开发环境与数据

 FlatMap.java

import com.flink.demo.DataSource;
import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.java.tuple.Tuple3;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.util.Collector;
import java.util.List;

public class FlatMap 
    
    public static void main(String[] args) throws Exception {
        final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        List> tuple3List = DataSource.getTuple3ToList();
        DataStream dataStream = env.fromCollection(tuple3List).flatMap(new FlatMapFunction,String>() {
            @Override
            public void flatMap(Tuple3 tuple3, Collector out) throws Exception {
                out.collect(tuple3.f0);
                out.collect(tuple3.f1);
                out.collect(tuple3.f2 + "");
            }
        });
        dataStream.print();
        env.execute("flink FlatMap job");
    }
}