Map mymap = new HashMap();
mymap.put("1","one");
mymap.put("1","not one");
mymap.put("1","surely not one");
//the following line is case 2 for duplicate
//mymap.put("1","one");
System.out.println(mymap.get("1"));

public V put(K key,
             V value)

Map<String, ArrayList<String>> hashMap=new HashMap<String,

while(it.hasNext()){
         String key=it.next().toString();
         tempList=hashMap.get(key);
         if(tempList!=null){
             for(String value: tempList){
                 System.out.println("Key : "+key+ " ,

} } .....   private void addValues(String key, String value){
    ArrayList tempList=null;

    if(hashMap.containsKey(key)){

       tempList=hashMap.get(key);

       if(tempList==null)
           tempList=new ArrayList();

        tempList.add(value);

    }else{
        tempList=new ArrayList();
        tempList.add(value);
    }

    hashMap.put(key,tempList);
} .....