【Flink1.14实战】Flink DataStream 算子 Map

Map

DataStream → DataStream

接受一个元素并产生一个元素。将输入流的值加倍的映射函数：

package quick;


import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;


public class MapExample {

    public static void main(String[] args) throws Exception {

        final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

        DataStream<Integer> dataStream = env
                .fromElements(1, 2, 3, 4, 5)
                .map(new MapFunction<Integer, Integer>() {
                    @Override
                    public Integer map(Integer value) throws Exception {
                        return 2 * value;
                    }
                });


        dataStream.print();

        env.execute("MapExample");
    }

}

修改pom

<version>1.0.1</version>
<mainClass>quick.MapExample </mainClass>

然后，将打包应用程序提交，Flink 的Web UI来提交作业监控集群的状态和正在运行的作业。

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