Spark之Streaming实时监听Hdfs文件目录

来源：互联网发布：淘宝手机地址转换编辑：程序博客网时间：2024/06/01 08:20

应用场景：我们使用Streaming实时监听指定的Hdfs目录，当该目录有新的文件增加会读取它，并完成单词计数的操作。
这里和上一篇的差别就是：上一篇用的是socketTextStream而这里用的是：textFileStream。
其他没有不同。
代码展示：

import java.util.Arrays;import org.apache.spark.SparkConf;import org.apache.spark.api.java.function.FlatMapFunction;import org.apache.spark.api.java.function.Function2;import org.apache.spark.api.java.function.PairFunction;import org.apache.spark.streaming.Durations;import org.apache.spark.streaming.api.java.JavaDStream;import org.apache.spark.streaming.api.java.JavaPairDStream;import org.apache.spark.streaming.api.java.JavaStreamingContext;import scala.Tuple2;public class SparkStreamDfs002 {    public static void main(String[] args) {        SparkConf conf = new SparkConf().setMaster("local[4]").setAppName("NetworkWordCount").set("spark.testing.memory",                "2147480000");        JavaStreamingContext jssc = new JavaStreamingContext(conf, Durations.seconds(1));        System.out.println(jssc);        //创建监听文件流        JavaDStream<String> lines=jssc.textFileStream("hdfs://192.168.61.128:9000/sparkStreaminput001/");        JavaDStream<String> words = lines.flatMap(new FlatMapFunction<String, String>() {            public Iterable<String> call(String x) {                System.out.println(Arrays.asList(x.split(" ")).get(0));                return Arrays.asList(x.split(" "));            }        });        JavaPairDStream<String, Integer> pairs = words.mapToPair(new PairFunction<String, String, Integer>() {            public Tuple2<String, Integer> call(String s) {                return new Tuple2<String, Integer>(s, 1);           }        });        JavaPairDStream<String, Integer> wordCounts = pairs.reduceByKey(new Function2<Integer, Integer, Integer>() {            public Integer call(Integer i1, Integer i2) {                return i1 + i2;            }        });        wordCounts.print();        wordCounts.dstream().saveAsTextFiles("hdfs://192.168.61.128:9000/sparkStream001/wordCount/", "spark");        jssc.start();         jssc.awaitTermination();    }}

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