Storing and Retrieving ArrayList values from hashmap

Question

I have a hashmap of the following type

HashMap> map=new HashMap>();    
<         


        

Answer 1

Fetch all at once =

List list = null;

if(map!= null) 
{ 
  list = new ArrayList(map.values()); 
}

For Storing =

if(map!= null) 
{ 
  list = map.get(keyString); 
   if(list == null)
    {
         list = new ArrayList();
    }
  list.add(value);
  map.put(keyString,list);
}