Simple implementation of a generic Bag : Collection « Collections Data Structure « Java

1. Java
2. Collections Data Structure
3. Collection

Simple implementation of a generic Bag

    

/*
 * FindBugs - Find Bugs in Java programs
 * Copyright (C) 2003-2007 University of Maryland
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

/**
 * Simple implementation of a Bag
 * 
 * @author pugh
 */
public class Bag<E> {
  final Map<E,Integer> map;
  
  public Bag() {
    map = new HashMap<E, Integer>();
  }
  public Bag(Map<E, Integer> map) {
   this.map = map;
  }
  public boolean add(E e) {
    Integer v = map.get(e);
    if (v == null) 
      map.put(e, 1);
    else map.put(e, v+1);
    return true;
  }
  public boolean add(E e, int count) {
    Integer v = map.get(e);
    if (v == null) 
      map.put(e, count);
    else map.put(e, v+count);
    return true;
  }
  public Set<E> keySet() {
    return map.keySet();
  }

  public Collection<Map.Entry<E, Integer>> entrySet() {
    return map.entrySet();
  }
  
  public int getCount(E e) {
      Integer v = map.get(e);
      if (v == null) 
        return 0;
      else return v;
  }

}

   
    
    
    
  

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