LibimsetiWithAnonymousRecommender.java

/*
 * Source code for listing 5.6
 * 
 */
package mia.recommender.ch05;

import java.io.IOException;
import java.util.List;

import org.apache.mahout.cf.taste.common.TasteException;
import org.apache.mahout.cf.taste.impl.model.GenericUserPreferenceArray;
import org.apache.mahout.cf.taste.impl.model.PlusAnonymousUserDataModel;
import org.apache.mahout.cf.taste.impl.model.file.FileDataModel;
import org.apache.mahout.cf.taste.model.DataModel;
import org.apache.mahout.cf.taste.model.PreferenceArray;
import org.apache.mahout.cf.taste.recommender.RecommendedItem;

public class LibimsetiWithAnonymousRecommender
    extends LibimsetiRecommender {

  private final PlusAnonymousUserDataModel plusAnonymousModel;

  public LibimsetiWithAnonymousRecommender()
      throws TasteException, IOException {
    this(new FileDataModel(readResourceToTempFile("ratings.dat")));
  }

  public LibimsetiWithAnonymousRecommender(DataModel model)
      throws TasteException, IOException {
    super(new PlusAnonymousUserDataModel(model));
    plusAnonymousModel =
        (PlusAnonymousUserDataModel) getDataModel();
  }

  public synchronized List<RecommendedItem> recommend(
      PreferenceArray anonymousUserPrefs, int howMany)
      throws TasteException {
    plusAnonymousModel.setTempPrefs(anonymousUserPrefs);
    List<RecommendedItem> recommendations =
        recommend(PlusAnonymousUserDataModel.TEMP_USER_ID, howMany, null);
    plusAnonymousModel.clearTempPrefs();
    return recommendations;
  }

  public static void main(String[] args) throws Exception {
    PreferenceArray anonymousPrefs =
        new GenericUserPreferenceArray(3);
    anonymousPrefs.setUserID(0,
        PlusAnonymousUserDataModel.TEMP_USER_ID);
    anonymousPrefs.setItemID(0, 123L);
    anonymousPrefs.setValue(0, 1.0f);
    anonymousPrefs.setItemID(1, 123L);
    anonymousPrefs.setValue(1, 3.0f);
    anonymousPrefs.setItemID(2, 123L);
    anonymousPrefs.setValue(2, 2.0f);
    LibimsetiWithAnonymousRecommender recommender =
        new LibimsetiWithAnonymousRecommender();
    List<RecommendedItem> recommendations =
        recommender.recommend(anonymousPrefs, 10);
    System.out.println(recommendations);
  }

}