autoboxing is that the conversion of primitive data types 
into wrapper class objects automatically.By using generic 
types of java 1.5,we an acheive it easily.By declaring, the 
collection classes as shown below we can do it.
HashSet<Integer> hs=new HashSet<Integer>();
hs.add(1);
hs.add(2);
Iterator it=hs.iterator(0;
while(it.hasNext())
System.out.println(it.next());