java.lang.ClassNotFoundException: JavaWordCount$1

在调用spark给的例子中，我们会碰到提交运行的时候会报空指针问题。那时因为spark集群中找不到你制定的class，所以我们需要手动的将包添加到当前的job中。以JavaWordCount为例，修改后的代码如下：

备注：在运行的参数中需要设置==》spark://localhost:7077  hdfs://localhost:9000/input/test.txt  hdfs://localhost:9000/input/result.txt

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* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
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import java.util.Arrays;
import java.util.regex.Pattern;

import org.apache.spark.api.java.JavaPairRDD;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
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 scala.Tuple2;

public final class JavaWordCount {
  private static final Pattern SPACE = Pattern.compile(" ");

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

    if (args.length < 2) {
      System.err.println("Usage: JavaWordCount <master> <file>");
      System.exit(1);
    }

    JavaSparkContext ctx = new JavaSparkContext(args[0], "JavaWordCount",
        System.getenv("SPARK_HOME"), JavaSparkContext.jarOfClass(JavaWordCount.class));
    ctx.addJar("/home/hadoop/Desktop/JavaSparkT.jar");
    JavaRDD<String> lines = ctx.textFile(args[1], 1);
   
    JavaRDD<String> words = lines.flatMap(new FlatMapFunction<String, String>() {
      @Override
      public Iterable<String> call(String s) {
        return Arrays.asList(SPACE.split(s));
      }
    });
   
    JavaPairRDD<String, Integer> ones = words.map(new PairFunction<String, String, Integer>() {
      @Override
      public Tuple2<String, Integer> call(String s) {
        return new Tuple2<String, Integer>(s, 1);
      }
    });
   
    JavaPairRDD<String, Integer> counts = ones.reduceByKey(new Function2<Integer, Integer, Integer>() {
      @Override
      public Integer call(Integer i1, Integer i2) {
        return i1 + i2;
      }
    });
    counts.saveAsTextFile(args[2]);
//    counts.s
    /*List<Tuple2<String, Integer>> output = counts.collect();
    for (Tuple2<?,?> tuple : output) {
      System.out.println(tuple._1() + ": " + tuple._2());
    }*/
    System.exit(0);
  }
}