Changes between Initial Version and Version 1 of WordCount

Timestamp:

Feb 6, 2009, 4:37:42 PM (15 years ago)

Author:

waue

Comment:

--

WordCount

@@ +1 @@
+'''WordCount.java'''
+
+{{{
+#!java
+        
+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<LongWritable, Text, Text, IntWritable> {
+    private final static IntWritable one = new IntWritable(1);
+    private Text word = new Text();
+        
+    public void map(LongWritable key, Text value, OutputCollector<Text, IntWritable> 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<Text, IntWritable, Text, IntWritable> {
+
+    public void reduce(Text key, Iterator<IntWritable> values, OutputCollector<Text, IntWritable> 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);
+ }
+        
+}
+}}}