Unable to understand Struts

I am studying in GNIIT from NIIT.
Here in 4th sem we have stuts also but I am not able to understand it.
I've made an application.That application is of book entry.
I have made the application but in that application when I enter the details of book, data base becomes updated but I did'nt get successfull msg.
it doesnat forwads on the success page.



package com.struts.controller;


import java.io.PrintWriter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import servlet.model.Book;
import servlet.model.BookService;

/**
*
* @author niit
*/
public class AddBookStruts extends org.apache.struts.action.Action {

/* forward name="success" path="" */
private static final String SUCCESS = "success";

/**
* This is the action called from the Struts framework.
* @param mapping The ActionMapping used to select this instance.
* @param form The optional ActionForm bean for this request.
* @param request The HTTP Request we are processing.
* @param response The HTTP Response we are processing.
* @throws java.lang.Exception
* @return
*/
@Override
public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception

{
PrintWriter out = response.getWriter();
try{

out.println("<a href='index.jsp'>Home Page</a>");
BookService bs=new BookService("C:\\data\\");

String strAuthor=request.getParameter("author");
String strPages=request.getParameter("pages");
String strDescription=request.getParameter("description");

int isbn=bs.AutoIncrement();
int pages=Integer.parseInt(strPages);

Book book=new Book(isbn,strAuthor,pages,strDescription);

bs.storeBook(book);

request.setAttribute("book",book);

return mapping.findForward(SUCCESS);
}

catch(Exception ex)
{
out.println(ex.toString());
}
finally
{

out.close();
}
return mapping.findForward("error");
}
}
---------------------------------------------------------------------------
package servlet.view;

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import servlet.model.Book;
import servlet.model.BookService;

/**
*
* @author niit
*/
public class AddBookServlet extends HttpServlet {

/**
* Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try
{
out.println("<a href='index.jsp'>Home Page</a>");

BookService bs=new BookService("C:\\data\\");

String strAuthor=request.getParameter("author");
String strPages=request.getParameter("pages");
String strDescription=request.getParameter("description");

int isbn=bs.AutoIncrement();
int pages=Integer.parseInt(strPages);

Book book=new Book(isbn,strAuthor,pages,strDescription);

bs.storeBook(book);

request.setAttribute("book",book);

return;

}
catch(Exception ex)
{
out.println(ex.toString());
}
finally {
out.close();
}
}

// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
* Handles the HTTP <code>GET</code> method.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}

/**
* Handles the HTTP <code>POST</code> method.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}

/**
* Returns a short description of the servlet.
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>

}
---------------------------------------------------------------------------
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/

package servlet.view;

import servlet.model.Book;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
*
* @author NIIT
*/
public class SuccessServlet extends HttpServlet {

/**
* Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
Book book=(Book) request.getAttribute("book");
try {
// out.println("<a href='index.jsp'>Home Page</a>");
// out.println("<h1>Success</h1>");
// out.println("<p>");
// out.println("Your request to add the Book title");
// out.println("<font color=green>");
// out.println("<u>");
// out.print("<i>" + book.getDescription()+ "</i>");
// out.println("</u>");
// out.println("</font>");
// out.println("By");
// out.println("<font color=green>");
// out.println("<u>");
// out.print("<i>" + book.getAuthor()+ "</i>");
// out.println("</u>");
// out.println("</font>");
// out.println(" was successful.");
// out.println("</p>");
} finally {
out.close();
}
}

// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
* Handles the HTTP <code>GET</code> method.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}

/**
* Handles the HTTP <code>POST</code> method.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}

/**
* Returns a short description of the servlet.
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>

}
---------------------------------------------------------------------------
<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE struts-config PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 1.3//EN"
"http://jakarta.apache.org/struts/dtds/struts-config_1_3.dtd">


<struts-config>
<form-beans>

</form-beans>

<global-exceptions>

</global-exceptions>

<global-forwards>
<forward name="welcome" path="/Welcome.do"/>
</global-forwards>

<action-mappings>
<action path="/Welcome" forward="/welcomeStruts.jsp"/>
<action path="/com.struts.controller" type="com.struts.controller.DeleteBookStruts">
<forward name="SuccessDelete" path="servlet.view"/>
<forward name="ErrorServlet" path="servlet.view"/>
</action>
<action path="/com.struts.controller" type="com.struts.controller.AddBookStruts">
<forward name="Success" path="/success.jsp"/>
<forward name="Error" path="/Error.jsp"/>
</action>

</action-mappings>


<controller processorClass="org.apache.struts.tiles.TilesRequestProcessor"/>

<message-resources parameter="com/myapp/struts/ApplicationResource"/>

<!-- ========================= Tiles plugin ===============================-->
<!--
This plugin initialize Tiles definition factory. This later can takes some
parameters explained here after. The plugin first read parameters from
web.xml, thenoverload them with parameters defined here. All parameters
are optional.
The plugin should be declared in each struts-config file.
- definitions-config: (optional)
Specify configuration file names. There can be several comma
separated file names (default: ?? )
- moduleAware: (optional - struts1.1)
Specify if the Tiles definition factory is module aware. If true
(default), there will be one factory for each Struts module.
If false, there will be one common factory for all module. In this
later case, it is still needed to declare one plugin per module.
The factory will be initialized with parameters found in the first
initialized plugin (generally the one associated with the default
module).
true : One factory per module. (default)
false : one single shared factory for all modules
- definitions-parser-validate: (optional)
Specify if xml parser should validate the Tiles configuration file.
true : validate. DTD should be specified in file header (default)
false : no validation

Paths found in Tiles definitions are relative to the main context.
-->
<plug-in className="org.apache.struts.tiles.TilesPlugin" >
<set-property property="definitions-config" value="/WEB-INF/tiles-defs.xml" />
<set-property property="moduleAware" value="true" />
</plug-in>

<!-- ========================= Validator plugin ================================= -->
<plug-in className="org.apache.struts.validator.ValidatorPlugIn">
<set-property
property="pathnames"
value="/WEB-INF/validator-rules.xml,/WEB-INF/validation.xml"/>
</plug-in>

</struts-config>
---------------------------------------------------------------------------
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<servlet>
<servlet-name>action</servlet-name>
<servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
<init-param>
<param-name>config</param-name>
<param-value>/WEB-INF/struts-config.xml</param-value>
</init-param>
<init-param>
<param-name>debug</param-name>
<param-value>2</param-value>
</init-param>
<init-param>
<param-name>detail</param-name>
<param-value>2</param-value>
</init-param>
<load-on-startup>2</load-on-startup>
</servlet>
<servlet>
<servlet-name>AddBookServlet</servlet-name>
<servlet-class>servlet.view.AddBookServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>action</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>AddBookServlet</servlet-name>
<url-pattern>/add.view</url-pattern>
</servlet-mapping>
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
---------------------------------------------------------------------------
<%--
Document : success
Created on : May 25, 2010, 11:56:30 AM
Author : NIIT
--%>

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Success Page</title>
</head>
<body>
<h1>Success!</h1>
<p>
Your request to add the Book title was successful.
</p>
</body>
</html>
---------------------------------------------------------------------------
<%@page contentType="text/html"%>
<%@page pageEncoding="UTF-8"%>

<%@ taglib uri="http://struts.apache.org/tags-bean" prefix="bean" %>
<%@ taglib uri="http://struts.apache.org/tags-html" prefix="html" %>
<%@ taglib uri="http://struts.apache.org/tags-logic" prefix="logic" %>

<html:html lang="true">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title><bean:message key="welcome.title"/></title>
<html:base/>
</head>
<body style="background-color: white">

<logic:notPresent name="org.apache.struts.action.MESSAGE" scope="application">
<div style="color: red">

</div>
</logic:notPresent>

<h3><bean:message key="welcome.heading"/></h3>
<p><bean:message key="welcome.message"/></p>
<a href="addbooks.jsp">Add Book</a>

</body>
</html:html>
---------------------------------------------------------------------------
<%@page contentType="text/html"%>
<%@page pageEncoding="UTF-8"%>

<jsp:forward page="Welcome.do"/>