FLink基于文件的Source

Flink基于文件的Source

基于文件的Source
默认情况下，Source读取完数据，程序就退出了，因为返回的是一个有限的数据流
readTextFile底层调用的是readFile,读取数据的方式为FileProcessingMode.PROCESS_ONCE

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



public class FileSource {


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


        Configuration configuration = new Configuration();
        configuration.setInteger("rest.port", 8081); //指定本地web页面的服务的端口号
        StreamExecutionEnvironment env = StreamExecutionEnvironment.createLocalEnvironmentWithWebUI(configuration);


        //调用FileSource
        DataStreamSource lines = env.readTextFile("/Users/xing/Desktop/a.txt");


        int parallelism = lines.getParallelism();


        System.out.println("readTextFile得到的DataStreamSource的并行度为："+ parallelism);


        lines.print();


        env.execute();


    }
}