我是java和hadoop的新手。我遵循这个教程(https://developpaper.com/simple-java-hadoop-mapreduce-program-calculate-average-score-from-package-to-submit-and-run/). 我在提供输入时做了一些小修改。请参考代码。

public class Score {

    public static class Map extends Mapper<LongWritable, Text, Text, IntWritable> {
        // Implement map function
        public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
            // Convert the data of the input plain text file to string
            String line = value.toString();
            // Split the input data into rows first
            StringTokenizer tokenizerArticle = new StringTokenizer(line, "\n");
            // Process each line separately
            while (tokenizerArticle.hasMoreElements()) {
                // Line by space
                StringTokenizer tokenizerLine = new StringTokenizer(tokenizerArticle.nextToken());
                String strName = tokenizerLine.nextToken(); // student name
                                                            // section
                String strScore = tokenizerLine.nextToken(); // grade section
                Text name = new Text(strName);
                int scoreInt = Integer.parseInt(strScore);
                // Output name and score
                context.write(name, new IntWritable(scoreInt));
            }
        }
    }

    public static class Reduce extends Reducer<Text, IntWritable, Text, IntWritable> {
        // Implement reduce function
        public void reduce(Text key, Iterable<IntWritable> values, Context context)
                throws IOException, InterruptedException {
            int sum = 0;
            int count = 0;
            Iterator<IntWritable> iterator = values.iterator();
            while (iterator.hasNext()) {
                sum += iterator.next().get(); // calculate the total score
                count++; // count the total number of accounts
            }
            Integer average = (int) sum / count; // calculate the average score
            context.write(key, new IntWritable(average));
        }
    }

    public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException {
        // TODO Auto-generated method stub
        Configuration conf = new Configuration();
        // " localhost:9000 "It needs to be set according to the actual
        // situation
        conf.set("mapred.job.tracker", "localhost:9000");
        // Input directory and output directory in an HDFS file system

        String[] ioArgs = new String[] { "score.txt", "output" };
        String[] otherArgs = new GenericOptionsParser(conf, ioArgs).getRemainingArgs();
        if (otherArgs.length != 2) {
            System.err.println("Usage: Score Average <in> <out>");
            System.exit(2);
        }

        Job job = new Job(conf, "Score Average");
        job.setJarByClass(Score.class);
        // Set map, combine and reduce processing classes
        job.setMapperClass(Map.class);
        job.setCombinerClass(Reduce.class);
        job.setReducerClass(Reduce.class);
        // Set output type
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
        // The input data set is divided into small data blocks splites to
        // provide a RecordReder implementation
        job.setInputFormatClass(TextInputFormat.class);
        // Provide an implementation of recordwriter, responsible for data
        // output
        job.setOutputFormatClass(TextOutputFormat.class);
        // Set input and output directories
        FileInputFormat.addInputPath(job, new Path(otherArgs[0]));
        FileOutputFormat.setOutputPath(job, new Path(otherArgs[1]));
        System.exit(job.waitForCompletion(true) ? 0 : 1);
    }

}

在那里，我使用maven在eclips中尝试了程序源代码。我为pom.xml文件添加了依赖项，如下所示。

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>mapreducedemocode</groupId>
  <artifactId>mapreducedemocode</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>mapreducedemocode</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.apache.hadoop</groupId>
      <artifactId>hadoop-client</artifactId>
      <version>2.7.3</version>
    </dependency>
  </dependencies>
</project>

但当我运行代码时，它会给出以下异常。

Exception in thread "main" java.lang.UnsatisfiedLinkError: org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Ljava/lang/String;I)Z
    at org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Native Method)

有人能帮我解决这个问题吗。请注意，我将输入文件（'score.txt）添加到项目中，并通过将参数添加为'score.txt output'来设置运行配置。提供论据有什么问题吗。