title: Creating Hadoop java example
body: <p>I know this question has been asked before but I cannot seem to figure it out.  I have a single node cluster setup using hadoop that is working correctly.  I am trying to compile the WordCount.java example:</p>
  
  <pre><code>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.mapred.*;
  import org.apache.hadoop.util.*;
  
  public class WordCount {
  
    public static class Map extends MapReduceBase implements Mapper&lt;LongWritable, Text, Text, IntWritable&gt; {
      private final static IntWritable one = new IntWritable(1);
      private Text word = new Text();
  
      public void map(LongWritable key, Text value, OutputCollector&lt;Text, IntWritable&gt; output, Reporter reporter) throws IOException {
        String line = value.toString();
        StringTokenizer tokenizer = new StringTokenizer(line);
        while (tokenizer.hasMoreTokens()) {
          word.set(tokenizer.nextToken());
          output.collect(word, one);
        }
      }
    }
  
    public static class Reduce extends MapReduceBase implements Reducer&lt;Text, IntWritable, Text, IntWritable&gt; {
      public void reduce(Text key, Iterator&lt;IntWritable&gt; values, OutputCollector&lt;Text, IntWritable&gt; output, Reporter reporter) throws IOException {
        int sum = 0;
        while (values.hasNext()) {
          sum += values.next().get();
        }
        output.collect(key, new IntWritable(sum));
      }
    }
  
    public static void main(String[] args) throws Exception {
      JobConf conf = new JobConf(WordCount.class);
      conf.setJobName("wordcount");
  
      conf.setOutputKeyClass(Text.class);
      conf.setOutputValueClass(IntWritable.class);
  
      conf.setMapperClass(Map.class);
      conf.setCombinerClass(Reduce.class);
      conf.setReducerClass(Reduce.class);
  
      conf.setInputFormat(TextInputFormat.class);
      conf.setOutputFormat(TextOutputFormat.class);
  
      FileInputFormat.setInputPaths(conf, new Path(args[0]));
      FileOutputFormat.setOutputPath(conf, new Path(args[1]));
  
      JobClient.runJob(conf);
    }
  }
  </code></pre>
  
  <p>I've installed hadoop-2.2.0 to /usr/local/hadoop/ but I cannot for the life of me figure out what .jar files I need to add in eclipse to import the org.apache.hadoop files.  I hardly ever use Java or eclipse but I've copied every .jar file in the hadoop home folder to a lib folder in my eclipse workspace and added the external .jars in the project settings.  Any idea what I am doing wrong?</p>