java to do simple paging operation using the subList

java in subList snapshot object list is selected, and does not change the value of the original object List, and thus the need for assignment.

 

Method parameters:

List <E> the subList ( int fromIndex, int toIndex);   // a parameter: set of index elements, two parameters: the first few elements. . . 

/ * E.g. list.subList (0,2) is the index starts from 0, take the second element, the result is an element index of 0,1 * /

Paging algorithm:

the try { 
         list.subList (the pageSize * (-pageNum. 1), the pageSize * pageNum); // start with an index 0, i.e. find the 10 0-9 
    } the catch (an IndexOutOfBoundsException E) { 
         list.subList (the pageSize * (pageNum -1 ), list.size ());   // the array bounds exception, take the last element 
    }

Lazy Loading in:

  try {
          list=list.subList(0,pageSize*pageNum);
      } catch (IndexOutOfBoundsException e) {
          list=list.subList(0,list.size());
      }