Question

我试图在eclipse中为hadoop执行WordCount程序，并且我收到了以下错误：

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
at WordCount.run(WordCount.java:22)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
at WordCount.main(WordCount.java:35)

我已经从互联网上复制了代码并且代码看起来很好但是为了参考我在这里粘贴代码：

WordCount.java

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.conf.*;
import org.apache.hadoop.io.*;
import org.apache.hadoop.mapred.*;
import org.apache.hadoop.util.*;

public class WordCount extends Configured implements Tool{
      public int run(String[] args) throws Exception
      {
        //creating a JobConf object and assigning a job name for     identification purposes
        JobConf conf = new JobConf(getConf(), WordCount.class);
        conf.setJobName("WordCount");

        //Setting configuration object with the Data Type of output Key   and Value
        conf.setOutputKeyClass(Text.class);
        conf.setOutputValueClass(IntWritable.class);

        //Providing the mapper and reducer class names
        conf.setMapperClass(WordCountMapper.class);
        conf.setReducerClass(WordCountReducer.class);
        //We wil give 2 arguments at the run time, one in input path and other is output path
        Path inp = new Path(args[0]);
        Path out = new Path(args[1]);
        //the hdfs input and output directory to be fetched from the command line
        FileInputFormat.addInputPath(conf, inp);
        FileOutputFormat.setOutputPath(conf, out);

        JobClient.runJob(conf);
        return 0;
  }

  public static void main(String[] args) throws Exception
  {
        // this main function will call run method defined above.
    int res = ToolRunner.run(new Configuration(), new WordCount(),args);
        System.exit(res);
  }

}

Answer 1

似乎你没有传递正确的命令行参数。

在hadoop中执行wordcount程序时出错

1 个答案: