CompareAlbumsByName.java :  » Music » harmonium » org » dazeend » harmonium » music » Java Open Source

package org.dazeend.harmonium.music;

import java.util.Comparator;

/**
 * @throws NullPointerException
 */
public class CompareAlbumsByName implements Comparator<Album> {

  /* (non-Javadoc)
   * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
   */
  public int compare(Album album1, Album album2) {
    
    // If one of the albums is null, then throw an exception
    if(album1 == null || album2 == null) {
      throw new NullPointerException();
    }
    
    // Sort by album name. If only one album has a name set, it should come before.
    if( ! album1.getAlbumNameTitleSortForm().equals( album2.getAlbumNameTitleSortForm() ) ) {
      if( album2.getAlbumNameTitleSortForm().equals("") ) {
        return -1;
      }
      else if( album1.getAlbumNameTitleSortForm().equals("") ) {
        return 1;
      }
      else  {
        return album1.getAlbumNameTitleSortForm().compareTo(album2.getAlbumNameTitleSortForm());
      }
    }
    
    // Sort finally by album release year
    Integer year1 = album1.getReleaseYear();
    Integer year2 = album2.getReleaseYear();
    
    // If one of the albums doesn't have a release year set (releaseYear == 0), then it should come after
    if(year1 == 0 && year2 == 0) {
      // Neither has a year set, so they are the same.
      return 0;
    }
    else if(year1 == 0) {
      // Album1 doesn't have a year set. It should come after.
      return 1;
    }
    else if(year2 == 0) {
      // Album2 doesn't have a year set. It should come after.
      return -1;
    }
    
    // Both albums have years set, so compare them.
    return year1.compareTo(year2);
  }
}