How to use model / Java / Pojo classes with JSP and Servlets ?.

Program to demonstrate how to use model / Java / Pojo classes with JSP and Servlets

Model Class in Java :

package com.hubberspot.model;

public class Customer {

 private String firstName; 
 private String lastName; 
 private String emailAddress;

 public Customer() {  
  firstName = "";
  lastName = "";
  emailAddress = "";
 }
 
 public Customer(String firstName , String lastName , String emailAddress) {
  this.firstName = firstName;
  this.lastName = lastName;
  this.emailAddress = emailAddress;
 }

 public String getFirstName() {
  return firstName;
 }
 public void setFirstName(String firstName) {
  this.firstName = firstName;
 }
 public String getLastName() {
  return lastName;
 }
 public void setLastName(String lastName) {
  this.lastName = lastName;
 }
 public String getEmailAddress() {
  return emailAddress;
 }
 public void setEmailAddress(String emailAddress) {
  this.emailAddress = emailAddress;
 }

}

Service Class in Java :

package com.hubberspot.utility;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;

import com.hubberspot.model.Customer;

public class CustomerService {

    public static void write(Customer customer, String filePath) {
 try {

  File file = new File(filePath);
  FileWriter writer = new FileWriter(file);
  PrintWriter out = new PrintWriter(writer);
   
  String firstName = customer.getFirstName();
  String lastName = customer.getLastName();
  String emailAddress = customer.getEmailAddress();
   
  out.println("First Name : "+ firstName+"" );
  out.println("Last Name : "+ lastName+"" );
  out.println("Email Address : "+ emailAddress+"" );

out.close();

 } catch (IOException e) {   
  e.printStackTrace();
 }
   }
}

subscribe.html

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<!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=ISO-8859-1">
<title>Email Subscription</title>
</head>
<body>
 <h1>Join Hubberspot's Email list</h1>
 <p>
  In order to join our email list, enter you name and email address
  below </br> and Click Submit button.
 </p>

 <form action="email_entry.jsp" method="get">
  <table cellspacing="5" border="0">
   <tr>
    <td align="right">First Name : </td>
    <td><input type="text" name="firstName"></td>
   </tr>
   <tr>
    <td align="right">Last Name : </td>
    <td><input type="text" name="lastName"></td>
   </tr>
   <tr>
    <td align="right">Email Address : </td>
    <td><input type="text" name="emailAddress"></td>
   </tr>
   
   <tr>
    <td></td>
    <td align="left"></br><input type="submit" value="Submit"></td>
   </tr>

  </table>
 </form>
</body>
</html>

email_entry.jsp

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<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
 pageEncoding="ISO-8859-1"%>
<!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=ISO-8859-1">
<title>Email Subscription</title>
</head>
<body>
<%@ page import="com.hubberspot.model.Customer" %> 
<%@ page import="com.hubberspot.utility.CustomerService" %> 

 <%
  // Get the form requests 
  String firstName = request.getParameter("firstName");
  String lastName = request.getParameter("lastName");
  String emailAddress = request.getParameter("emailAddress");
  
  // Get the complete real path for subscription.txt
  ServletContext context = request.getServletContext();
  String filePath = context.getRealPath("/subscription.txt");
    
  // Using DataModel in a JSP
  Customer customer = new Customer(firstName, lastName, emailAddress);
  
  // Using the CustomerService class to write info to file
  CustomerService.write(customer, filePath);
 %>

 <h1>Thanks for joining Hubberspot's Email list</h1>
 <p>Kindly have a look what you have entered :</p>

 <table cellspacing="0" cellpadding="5" border="1">
  <tr>
   <td align="right">First Name :</td>
   <td><%=customer.getFirstName()%></td>
  </tr>

  <tr>
   <td align="right">Last Name :</td>
   <td><%=customer.getLastName()%></td>
  </tr>

  <tr>
   <td align="right">Email Address :</td>
   <td><%=customer.getEmailAddress()%></td>
  </tr>
 </table>

 <p>
  To provide correct information, click 'back' on browser window </br>or
  click on Back button below :
 </p>
 
 <form action="subscribe.html" method="post">
 <input type="submit" value="Back">
 </form>

</body>
</html>

How to run the application :

Deploy the application on the server.
Run and request for subscribe.html.
After filling the necessary data , submit the data to email_entry.jsp.
email_entry.jsp displays the information in it .
A file subscrition.txt gets created and data is written to it by CustomerService class.