questions from an xml file

1)Servlet.java

import java.io.*;
import java.util.*;
import form.Student;
import org.w3c.dom.*;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.servlet.*;
import javax.servlet.http.*;

public class Servlet extends HttpServlet {
    int offset;
    int length;
    List list;

    protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {

        int maxEntriesPerPage = 1;
        int page = 1;
        String pageNumberValue = request.getParameter("pageNumber");

        if (pageNumberValue != null) {
            try {
                page = Integer.parseInt(pageNumberValue);
                System.out.println("Page Number:" + page);
            } catch (NumberFormatException e) {
                e.printStackTrace();
            }
        }
        int offset = maxEntriesPerPage * (page - 1);
        TestList(offset, maxEntriesPerPage);

        HttpSession httpSession = request.getSession();
        httpSession.setAttribute("pages", getPages());
        httpSession.setAttribute("studentDetails", getListByLength());

        RequestDispatcher dispatcher = request.getRequestDispatcher("/jsp/paging.jsp");
        dispatcher.forward(request, response);
    }
    public void fillList() {
        list = new ArrayList();
       try{
  File file = new File("c:\\file.xml");
  DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
  DocumentBuilder db = dbf.newDocumentBuilder();
  Document document = db.parse(file);
  document.getDocumentElement().normalize();
  System.out.println("Root element "+ document.getDocumentElement().getNodeName());
  NodeList node = document.getElementsByTagName("student");
  System.out.println("Information of the students");

  for(int i = 0; i < node.getLength(); i++){
  Node firstNode = node.item(i);
  if(firstNode.getNodeType()== Node.ELEMENT_NODE){
  Element element = (Element) firstNode;
  NodeList firstNameElemntList = element.getElementsByTagName("name");
  Element firstNameElement = (Element) firstNameElemntList.item(0);
  NodeList firstName = firstNameElement.getChildNodes();
  Node n1=firstName.item(0);
  String name=n1.getNodeValue();

  NodeList lastNameElementList = element.getElementsByTagName("address");
  Element lastNameElement = (Element)lastNameElementList.item(0);
  NodeList lastName = lastNameElement.getChildNodes();
  Node n2=lastName.item(0);
  String address=n2.getNodeValue();
  list.add(new Student(name,address));
   }
  }
  for(Student st:list){
  System.out.println(st.getName()+"\t"+st.getAddress());
  }
  }
  catch (Exception e) {
  e.printStackTrace();
  }
    }
    public void TestList(int offset, int length) {
        this.offset = offset;
        this.length = length;
        fillList();
    }
    public ArrayList getListByLength() {
        ArrayList arrayList = new ArrayList();
        int to = this.offset + this.length;
        if (this.offset > list.size())
            this.offset = list.size();
        if (to > list.size())
            to = list.size();
        for (int i = this.offset; i < to; i++) {
            arrayList.add(list.get(i));
        }
        return arrayList;
    }
    public List getPages() {
        List pageNumbers = new ArrayList();
        int pages = list.size() / this.length;
        if (list.size() % this.length != 0) {
            pages = pages + 1;
        }
        for (int i = 1; i <= pages; i++) {
            pageNumbers.add(new Integer(i));
        }
        return pageNumbers;
    }

continue..

2)Student.java:

package form;
import java.io.*;

public class Student implements Serializable {

    private String name;
    private String address;


    public Student(String name, String address) {
        this.name = name;
        this.address = address;

    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }
}

The above java class is a bean and should be located inside /classes/form/Student.

3)paging.jsp:

<%@page import="java.util.List"%>
<%@page import="form.Student"%>
<html>
<h1>Pagination</h1>
<%
    List list = (List) session.getAttribute("studentDetails");
    List pageNumbers = (List) session.getAttribute("pages");
%>
<table border="1">
    <tr><th>Name</th><th>Address</th><th>Age</th><th>Degree</th></tr>
    <%
        for (int i = 0; i < list.size(); i++) {
        Student st = (Student) list.get(i);
        %>
                <tr>
                <td><%=st.getName()%></td>
                <td><%=st.getAddress()%></td>

        <%
        }
        %>
        <td border=1 align="right">
        <form method="get" action="../PaginationServlet">
        <table>
            <tr>
                <%
                    for (int i = 0; i < pageNumbers.size(); i++) {
                %>
                <td><a href="/examples/PaginationServlet?pageNumber=<%=pageNumbers.get(i)%>"><%=pageNumbers.get(i)%></a></td>
                <%
                    }
                %>
            </tr>
        </table>
        </form>
        </td>
    </tr>
</table>
</html>