java Flink（七）从集合读取数据

最新推荐文章于 2022-07-15 10:25:04 发布

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最新推荐文章于 2022-07-15 10:25:04 发布

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分类专栏： Java Flink Java

本文链接：https://blog.youkuaiyun.com/qq_40771567/article/details/115177564

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本文介绍了如何使用Apache Flink进行流处理，通过一个简单的SourceTest1_Collection程序展示了如何从集合中读取SensorReading对象，并打印输出数据流。程序创建了一个包含多个传感器读数的DataStream，并展示了如何将数据转换为Integer类型的数据流，最后执行了Flink作业。

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今天继续学习Flink流处理的集合处理

上边是我们创建的传感器对象，下边是Flink流处理程序

SensorReading:

package beans;

//传感器温度读数的数据类型
public class SensorReading {
    //属性 id,时间戳,温度值
    private String id;
    private Long timestamp;
    private Double temperature;

    public SensorReading() {
    }

    public SensorReading(String id, Long timestamp, Double temperature) {
        this.id = id;
        this.timestamp = timestamp;
        this.temperature = temperature;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public Long getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(Long timestamp) {
        this.timestamp = timestamp;
    }

    public Double getTemperature() {
        return temperature;
    }

    public void setTemperature(Double temperature) {
        this.temperature = temperature;
    }

    @Override
    public String toString() {
        return "SensorReading{" +
                "id='" + id + '\'' +
                ", timestamp=" + timestamp +
                ", temperature=" + temperature +
                '}';
    }
}

SourceTest1_Collection

package source;

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

import java.util.Arrays;
import java.util.List;

public class SourceTest1_Collection {
    public static void main(String[] args) throws Exception {
        //创建执行环境
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        //设置并行调度
        //env.setParallelism(1);
        //从集合中读取数据
        DataStream<SensorReading> dataStream = env.fromCollection(Arrays.asList(new SensorReading("sensor_1", 1537718199L, 35.8),
                new SensorReading("sensor_6", 1547718201L, 15.4),
                new SensorReading("sensor_7", 1547718202L, 6.7),
                new SensorReading("sensor_10", 1547718205L, 38.1)));

        DataStream<Integer> integerDataStream = env.fromElements(1, 2, 4, 67, 189);
        //打印输出
        dataStream.print("data");
        integerDataStream.print("int");
        //执行 Flink的jobName
        env.execute("SensorReading");
    }
}

查看执行结果：