Mapreduce2程序错误：不是有效的JAR

Question

我在Ubuntu上安装了Hadoop 2.2.0版。我跑的时候：

yarn jar
hadoop/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.2.0.jar
wordcount /user/ubuntu/wordcount/input/file01.txt /output

运行良好。

当我运行示例程序时，使用Eclipse导出实用程序创建JAR，并使用：

运行

yarn jar /user/ubuntu/WordCountNew.jar com.sample.WordCountNew
/user/ubuntu/wordcount/input/file01.txt /output9

它显示：Not a valid JAR: /user/ubuntu/WordCountNew.jar

当我在Eclipse中编译代码时，它也会显示以下错误：

2015-02-02 16:08:53,077 WARN  [main] util.NativeCodeLoader (NativeCodeLoader.java:<clinit>(62)) - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
    at com.kumar.WordCountNew.main(WordCountNew.java:62)

代码：

package com.sample;

import java.io.IOException;
import java.util.*;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.conf.*;
import org.apache.hadoop.io.*;
import org.apache.hadoop.mapreduce.*;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;

public class WordCountNew {
    public static class Map extends Mapper<LongWritable, Text, Text, IntWritable> {
        private final static IntWritable one = new IntWritable(1);
        private Text word = new Text();

        public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
            String line = value.toString();
            StringTokenizer tokenizer = new StringTokenizer(line);

            while (tokenizer.hasMoreTokens()) {
                word.set(tokenizer.nextToken());
                context.write(word, one);
            }
        }
    }

    public static class Reduce extends Reducer<Text, IntWritable, Text, IntWritable> {
        public void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {
            int sum = 0;
            for (IntWritable val : values) {
                sum = sum + val.get();
                context.write(key, new IntWritable(sum));
            }
        }
    }

    public static void main(String[] args) throws Exception {
        Configuration conf = new Configuration();
        Job job = new Job(conf, "wordcount");
        job.setJarByClass(WordCountNew.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
        job.setMapperClass(Map.class);
        job.setReducerClass(Reduce.class);
        job.setInputFormatClass(TextInputFormat.class);
        job.setOutputFormatClass(TextOutputFormat.class);
        FileInputFormat.addInputPath(job, new Path(args[0]));
        FileOutputFormat.setOutputPath(job,new Path(args[1]));
        job.waitForCompletion(true);
    }
}