Java Code Examples for org.apache.hadoop.mapreduce.Reducer.Context#write()

The following examples show how to use org.apache.hadoop.mapreduce.Reducer.Context#write() . You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example 1
Source File: HistogramRatings.java    From big-c with Apache License 2.0 6 votes vote down vote up 
public void map(Object key, Text value, 
    Context context) throws IOException, InterruptedException{

  int rating, reviewIndex, movieIndex;
  String reviews = new String();
  String tok = new String();
  String ratingStr = new String();

  String line = ((Text)value).toString();
  movieIndex = line.indexOf(":");
  if (movieIndex > 0) {
    reviews = line.substring(movieIndex + 1);
    StringTokenizer token = new StringTokenizer(reviews, ",");
    while (token.hasMoreTokens()) {
      tok = token.nextToken();
      reviewIndex = tok.indexOf("_");
      ratingStr = tok.substring(reviewIndex + 1);
      rating = Integer.parseInt(ratingStr);
      context.write(new IntWritable(rating), one);
    }
  }
}
Example 2
Source File: Step32.java    From recsys-offline with Apache License 2.0 6 votes vote down vote up 
public void map(VarLongWritable key,VectorWritable value,Context context) throws IOException, InterruptedException{  

                long userID=key.get();  
                Vector userVector=value.get();  
                Iterator<Vector.Element> it=userVector.nonZeroes().iterator();  
                IntWritable itemi=new IntWritable();  
                while(it.hasNext()){  
                    Vector.Element e=it.next();  
                    int itemIndex=e.index();  
                    float preferenceValue=(float)e.get();  
                    itemi.set(itemIndex);  
                    context.write(itemi, new VectorOrPrefWritable(userID,preferenceValue));  
                   System.out.println("item :"+itemi+",userand val:"+userID+","+preferenceValue);  
                } 
              
        }
Example 3
Source File: MutiWordcount.java    From big-c with Apache License 2.0 5 votes vote down vote up 
public void map(Object key, Text value, Context context
                ) throws IOException, InterruptedException {
  StringTokenizer itr = new StringTokenizer(value.toString());
  while (itr.hasMoreTokens()) {
    word.set(itr.nextToken());
    context.write(word, one);
  }
}
Example 4
Source File: MutiWordcount.java    From big-c with Apache License 2.0 5 votes vote down vote up 
public void reduce(Text key, Iterable<IntWritable> values, 
                   Context context
                   ) throws IOException, InterruptedException {
  int sum = 0;
  for (IntWritable val : values) {
    sum += val.get();
  }
  result.set(sum);
  context.write(key, result);
}
Example 5
Source File: HistogramRatings.java    From big-c with Apache License 2.0 5 votes vote down vote up 
public void reduce(IntWritable key, Iterable<IntWritable> values, Context context
        ) throws IOException, InterruptedException {
  int sum = 0;
  for (IntWritable val : values) {
      sum += val.get();
  }
  context.write(key, new IntWritable(sum));
}
Example 6
Source File: Step32.java    From recsys-offline with Apache License 2.0 5 votes vote down vote up 
public void reduce(IntWritable key,Iterable<VectorOrPrefWritable> values ,Context context ) throws IOException, InterruptedException{  
      
    for(VectorOrPrefWritable va:values){  
        context.write(key, va);  
        System.err.println("key"+key.toString()+",vlaue"+va);  
    }  
}