How to do the paging while reading from the file !!!

Question

I've able to display the contents of the file in my jsp as a tabular form. I want to apply the paging concept in my jsp page. As i did in my database project there i's sending the next value as a parameter and it works.
But when i retrieving the value from the file then i'm not able to get particular values anyhow i'm using the concepts of getLineNumber() but unable to get the previous one worked. I want to diplay only the first 20 contents of the file then, by clicking the next button he should be able to view the next 20 contents of the file. Please help me out for this problem. If possible send me the codes too it'll very helpful for me.
in advance thanks....

Answer 1

I hope the following code will help u.
If your bean is:
public class yourBean
private int startIndex ;
private int pageSize ;
private int endIndex ;
public void useBean()
startIndex = 0;
pageSize = 10;
endIndex = pageSize;
public setters and getters for each of the above.
In servlet :
doGet/doPost:
yourBean uBean =
(yourBean)sess.getAttribute("urBean");
int sIndex = uBean.getStartIndex();
int eIndex = uBean.getEndIndex();
int pSize = uBean.getPageSize();
if (sIndex = 0)
//means first time
dont do anything
if ((sIndex >0)&&(sIndex <
uBean.getRecords().size())))
eIndex = sIndex + pSize - 1;
sIndex = eIndex;
//update Indexes to the bean
uBean.setStartIndex(sIndex);
uBean.setEndIndex(eIndex);
sess.setAttribute("urBean",uBean);
res.sendRedirect("yourJSP.jsp",req,res);
In yourJSP.jsp:
<jsp:useBean id="urBean" type="...." scope="session"
/>
<%
int sIndex = urBean.getStartIndex();
int eIndex = urBean.getEndIndex();
for (int
i=sIndex;(i<=eIndex)&&(i<urBean.getRecords().size()))
out.println(....);
if (eIndex >= urBean.getRecords().size())
out.println("NExt");
else
out.println("<a href=yourServlet>Next</a>");
if (sIndex <= 0)
out.println("Previous");
else
out.println("<a href=yourServlet>Previous</a>");
%>