Android Open Source - Profiterole Map Callback

• Back to Development/map  ↑

From Project

Back to project page Profiterole.

License

The source code is released under:

Apache License

Java Source Code

package profiterole.mapreduce;
/* w w w  .j av  a 2s. c o m*/
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.concurrent.Callable;

/** loader to workable basic unit. The units are processed concurrently 
 * 
 * @author Boris Farber
 *
 * @param <InputUnit>
 */
public class MapCallback<InputUnit> {

  public Callable<OutputUnit> makeWorker(final InputUnit inputUnit) {
    return new Callable<OutputUnit>() {  

      @Override
      public OutputUnit call() throws Exception {
        return  new OutputUnit(new File(inputUnit.toString()));
      }
    };
  }

  public static class OutputUnit {

    private File key;
    private List<String> wordList = new ArrayList<String>();
    private HashMap<String, Integer> map;

    public  OutputUnit(File key) {
      //TODO what to todo with the line below
      System.out.println("Processing " + key);
      this.key = key;

      fileToWords();
      map = new Combiner().reduce(wordList);
    }

    public void fileToWords() {
      BufferedReader br = null;
      try {
        br = new BufferedReader(new FileReader(key));
        String line;

        while((line = br.readLine()) != null) {

          // TODO do more separations, the regex line below has some problems
          // add smart methods to have the code one time
          
          // TODO move to method and check few times
          String[] tokens = line.trim().split("((?<=\\s\\w{1,10})[^\\w\\s])?\\.?\\s|[^\\w\\s]$"); 

          for (String t : tokens) {            
            
            // TODO not sure about the loop here, but may be good idea b/c 
            // this is concurrent with zero side effects
            for (int i = 0; i < 3; i++) {
              if(t.endsWith(".") || t.endsWith("?") || t.endsWith("!") || t.endsWith(",") || t.endsWith("\"") ||
                  t.endsWith("'") || t.endsWith("`") || t.endsWith("*")
                  || t.endsWith("(") || t.endsWith(")")) {
                t = t.substring(0, t.length() -1);
              }
              if(t.startsWith(".") || t.startsWith("?") || t.startsWith("!") || t.startsWith(",") ||
                  t.startsWith("\"") || t.startsWith("'") || t.startsWith("`") || t.startsWith("`")
                  || t.startsWith("(") || t.startsWith(")")) {
                t = t.substring(1, t.length());
              }
            }
            
            wordList.add(t);
          }    
        }  
      } catch( IOException e ) {
        e.printStackTrace();
      } finally {
        try {
          br.close();
        } catch( IOException ex ) {
          ex.printStackTrace();
        }
      }
    }

    public HashMap<String, Integer> getMap() {
      return map;
    }
  }

  /** java limitation everything is class, can't make static b/c the object is per
   *  thread
   *
   * referential transparency
   */
  private static class Combiner {

    public HashMap<String, Integer> reduce(List<String> wordList){

      HashMap<String, Integer> map = new HashMap<String, Integer>();      
      for (String word : wordList) {
        if(map.containsKey(word))
        {
          int value = map.get(word).intValue();
          value++;
          map.put(word, value);
        }
        else
        {
          map.put(word, new Integer(1));
        }
      }    
      return map;
    }
  }
}

Java Source Code List

• Back to Development/map  ↑