Structure dictionnaire java

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

/**
 * Created on 17-avr.-07
 * 
 * @author: HackTrack
 */

public class DictionaryTest extends HashMap<String, List<String>>{

	public DictionaryTest(){
		super();
	}	
	
	public List putValue(String key,String value){
		List<String> list = get(key);
		if(list==null){
			list = new ArrayList<String>();
			super.put(key, list);
		}
		if(!list.contains(value)){
			list.add(value);
		}
	return list;
	}
}