PageAction.java

//setter and getter of pagination and currentPage is ignored
private List<Integer> pagination = new ArrayList<Integer>();
int up = (currentPage / 20 + 1) * 20 + currentPage % 20 + 1 -10;
int down = (currentPage / 20) * 20 + currentPage % 20 - 10;
for( int i = down; i  < up; i ++){
                        if(i >= 1)
			   pagination.add(i);
}