how to browse folder and directory in jsp

how to browse folder and directory in my jsp page.i have done my coding part for browsing directory but dont know how to get files after that.and also i want to show limited directories based on last modified date for eg:if the directory contains 10 folders i need to show 5 folders based on last modified date and it should be updated automatically.

 <%
response.setIntHeader("Refresh", 30);
String root="/home/adapco/Desktop/Startest/";
java.io.File file;
java.io.File dir = new java.io.File(root);
String[] list = dir.list();
for (int i = 0; i < list.length; i++) 
{
file = new java.io.File(root + list[i]);
 if (file.isDirectory()) {
%>
<li><a href="Startest/<%=list[i]%>" target="sss"><%=list[i]%></a><br>
<%
 }
 }
%>