TFIDF code

TFIDF is 3 pair of map-reduce program
TF&DF can be achieved from simple map-reduce tasks, here posted the third map reduce task to find out the TFIDF final deliverables.  
Custom Key

public class Key implements WritableComparable<Key>{

 Text word;
IntWritable type;
public Key() {
word = new Text();
type = new IntWritable();
}


public Text getWord() {
return word;
}
public void setWord(Text word) {
this.word = word;
}
public IntWritable getType() {
return type;
}
public void setType(IntWritable type) {
this.type = type;
}
@Override
public void readFields(DataInput arg0) throws IOException {
// TODO Auto-generated method stub
this.word.readFields(arg0);
this.type.readFields(arg0);
}

 @Override
public void write(DataOutput arg0) throws IOException {
// TODO Auto-generated method stub
this.word.write(arg0);
this.type.write(arg0);
}

 @Override
public int compareTo(Key o) {
// TODO Auto-generated method stub
int cmp = this.word.compareTo(o.getWord());
if(cmp == 0){
cmp = this.type.compareTo(o.getType());
}
return cmp;
}

 }

Custom Value

public class Value implements Writable{
 Text filename;
 IntWritable tf;
 IntWritable df;
 public Value() {
// TODO Auto-generated constructor stub
filename=new Text();
tf=new IntWritable();
df=new IntWritable();
 }
@Override
public void readFields(DataInput in) throws IOException {
// TODO Auto-generated method stub
this.filename.readFields(in);
this.tf.readFields(in);
this.df.readFields(in);
}

@Override
public void write(DataOutput out) throws IOException {
// TODO Auto-generated method stub
this.filename.write(out);
this.tf.write(out);
this.df.write(out);
}
public Text getFilename() {
return filename;
}
public void setFilename(Text filename) {
this.filename = filename;
}
public IntWritable getTf() {
return tf;
}
public void setTf(IntWritable tf) {
this.tf = tf;
}
public IntWritable getDf() {
return df;
}
public void setDf(IntWritable df) {
this.df = df;
}

}

Mapper

public class Mappe extends Mapper<LongWritable, Text, Key, Value>{
int type = 0;
Key k = new Key();
Value v = new Value();
@Override
protected void setup(Context context)throws IOException, InterruptedException {
Path fileName = ((FileSplit)context.getInputSplit()).getPath();
String file = fileName.getName();
if(file.equalsIgnoreCase("TF")){
type = 1;
}else{
type = 0;
}
}
@Override
protected void map(LongWritable key, Text value,Context context)throws IOException, InterruptedException {
  String[] splits = value.toString().split("\\W+");
  if(type == 1){
     k.setWord(new Text(splits[0]));
k.setType(new IntWritable(type));
 
     v.setFilename(new Text(splits[1]));
     v.setTf(new IntWritable(Integer.parseInt(splits[2])));
}else{
     k.setWord(new Text(splits[0]));
k.setType(new IntWritable(type));
 
     v.setDf(new IntWritable(Integer.parseInt(splits[1])));
}
context.write(k, v);
}
}

Grouping Comparator 

public class GrpCMP extends WritableComparator{

protected GrpCMP() {
super(Key.class,true);
}
@Override
public int compare(WritableComparable a, WritableComparable b) {
// TODO Auto-generated method stub
Key p1= (Key) a;
Key p2= (Key) b;
int cmp = p1.getWord().compareTo(p2.getWord());
return cmp;
}
}

Reducer

public class Reduce extends Reducer<Key, Value, Text, Text> {
@Override
protected void reduce(Key k, Iterable<Value> v,Context context)throws IOException, InterruptedException {
Iterator<Value> itr = v.iterator();
Value val = itr.next();
int Df = val.getDf().get();
Double a = (double) (5/Df);
while(itr.hasNext()){
Value val1=itr.next();
String file=val1.getFilename().toString();
int Tf=val1.getTf().get();
Double logval = Math.log(a) * Tf;
context.write(new Text(k.getWord()+" \t\t:\t "+file),new Text("\t\t"+logval.toString()));
}
}
}

Comments

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