JSP Servlet MVC Example with Database

In this quick article, we’ll create a small web application that implements the Model View Controller (MVC) design pattern, using basic Servlets and JSPs.
Model-View-Controller (MVC) is a pattern used in software engineering to separate the application logic from the user interface. As the name implies, the MVC pattern has three layers.
The Model defines the business layer of the application, the Controller manages the flow of the application, and the View defines the presentation layer of the application.
Get the source code of this tutorial on my GitHub Repository.

Video

This tutorial is explained in the below Youtube Video. Subscribe to my youtube channel to learn more about Spring boot at Java Guides - YouTube Channel.

Benefits of MVC in JSP and Servlet Web Application

  1. Minimizes HTML code in Servlet no more: out.println(…) in Servlet code.
  2. Minimize Java business logic in JSPs no more large scriptlets in JSP code
  3. It separates the presentation layer from the business layer
  4. The Controller performs the action of invoking the Model and sending data to View
  5. The Model is not even aware that it is used by some web application or a desktop application

Model-View-Controller (MVC)


From the above diagram, here is MVC flow:
1. The web browser sends an HTTP request to a controller (Servlet).
2. The controller (servlet) gets a model object with data from the database or other sources.
3. The controller(servlet) redirects to a web page (JSP) with model data.
4. Finally, the web page(JSP) will be displayed with model data on the browser.

Model-View-Controller Layers Overview

  1. The Model Layer - This is the data layer which contains the business logic of the system, and also represents the state of the application. It’s independent of the presentation layer, the controller fetches the data from the Model layer and sends it to the View layer.
  2. The Controller Layer - The controller layer acts as an interface between View and Model. It receives requests from the View layer and processes them, including the necessary validations.
  3. The View Layer - This layer represents the output of the application, usually some form of UI. The presentation layer is used to display the Model data fetched by the Controller.

Java MVC Example using JSP, Servlet with Database Example

To implement a web application based on MVC design pattern, we’ll create an Employee Registration module using JSPServletJDBC and MySQL database.
EmployeeServlet class will act as a Controller, and for the presentation layer, we’ll create employees.jsp page.

Before getting started, let's first setup the database.

1. MySQL Database Setup

Let's create a database named "mysql_database" in MySQL. Let's create an employee table using below DDL script:
CREATE TABLE `employee` (
   `id` int(3) NOT NULL,
   `first_name` varchar(20) DEFAULT NULL,
   `last_name` varchar(20) DEFAULT NULL,
   `username` varchar(250) DEFAULT NULL,
   `password` varchar(20) DEFAULT NULL,
   `address` varchar(45) DEFAULT NULL,
   `contact` varchar(45) DEFAULT NULL,
   PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
SELECT * FROM mysql_database.employee; 

2. Model Layer

Let's create the Employee class which will act as our Model layer.

Employee

package net.javaguides.jsp.jdbc.bean;

import java.io.Serializable;

/**
 * JavaBean class used in jsp action tags.
 * @author Ramesh Fadatare
 */
public class Employee implements Serializable {
    /**
     * 
     */
    private static final long serialVersionUID = 1 L;
    private String firstName;
    private String lastName;
    private String username;
    private String password;
    private String address;
    private String contact;
    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 getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public String getContact() {
        return contact;
    }
    public void setContact(String contact) {
        this.contact = contact;
    }
}

3. DAO Layer

EmployeeDao.java

Let's create EmployeeDao class which contains JDBC code to connect with MySQL database. Add the following code to an EmployeeDao class:
package net.javaguides.jsp.jdbc.database;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

import net.javaguides.jsp.jdbc.bean.Employee;

public class EmployeeDao {

    public int registerEmployee(Employee employee) throws ClassNotFoundException {
        String INSERT_USERS_SQL = "INSERT INTO employee" +
            "  (id, first_name, last_name, username, password, address, contact) VALUES " +
            " (?, ?, ?, ?, ?,?,?);";

        int result = 0;

        Class.forName("com.mysql.jdbc.Driver");

        try (Connection connection = DriverManager
            .getConnection("jdbc:mysql://localhost:3306/mysql_database?useSSL=false", "root", "root");

            // Step 2:Create a statement using connection object
            PreparedStatement preparedStatement = connection.prepareStatement(INSERT_USERS_SQL)) {
            preparedStatement.setInt(1, 1);
            preparedStatement.setString(2, employee.getFirstName());
            preparedStatement.setString(3, employee.getLastName());
            preparedStatement.setString(4, employee.getUsername());
            preparedStatement.setString(5, employee.getPassword());
            preparedStatement.setString(6, employee.getAddress());
            preparedStatement.setString(7, employee.getContact());

            System.out.println(preparedStatement);
            // Step 3: Execute the query or update query
            result = preparedStatement.executeUpdate();

        } catch (SQLException e) {
            // process sql exception
            printSQLException(e);
        }
        return result;
    }

    private void printSQLException(SQLException ex) {
        for (Throwable e: ex) {
            if (e instanceof SQLException) {
                e.printStackTrace(System.err);
                System.err.println("SQLState: " + ((SQLException) e).getSQLState());
                System.err.println("Error Code: " + ((SQLException) e).getErrorCode());
                System.err.println("Message: " + e.getMessage());
                Throwable t = ex.getCause();
                while (t != null) {
                    System.out.println("Cause: " + t);
                    t = t.getCause();
                }
            }
        }
    }
}

4. Controller Layer

Let's create an EmployeeServlet class to process HTTP request parameters and redirect to the appropriate JSP page after request data stored in the database:
package net.javaguides.employeemanagement.web;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import net.javaguides.employeemanagement.dao.EmployeeDao;
import net.javaguides.employeemanagement.model.Employee;

/**
 * @email Ramesh Fadatare
 */

@WebServlet("/register")
public class EmployeeServlet extends HttpServlet {
    private static final long serialVersionUID = 1 L;
    private EmployeeDao employeeDao;

    public void init() {
        employeeDao = new EmployeeDao();
    }

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

        String firstName = request.getParameter("firstName");
        String lastName = request.getParameter("lastName");
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String address = request.getParameter("address");
        String contact = request.getParameter("contact");

        Employee employee = new Employee();
        employee.setFirstName(firstName);
        employee.setLastName(lastName);
        employee.setUsername(username);
        employee.setPassword(password);
        employee.setContact(contact);
        employee.setAddress(address);

        try {
            employeeDao.registerEmployee(employee);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        response.sendRedirect("employeedetails.jsp");
    }
}

5. View Layer

employeeregister.jsp

Let's design employee registration HTML form with the following fields:
  • firstName
  • lastName
  • username
  • password
  • address
  • contact
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
 pageEncoding="ISO-8859-1"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
 <div align="center">
  <h1>Employee Register Form</h1>
  <form action="<%= request.getContextPath() %>/register" method="post">
   <table style="with: 80%">
    <tr>
     <td>First Name</td>
     <td><input type="text" name="firstName" /></td>
    </tr>
    <tr>
     <td>Last Name</td>
     <td><input type="text" name="lastName" /></td>
    </tr>
    <tr>
     <td>UserName</td>
     <td><input type="text" name="username" /></td>
    </tr>
    <tr>
     <td>Password</td>
     <td><input type="password" name="password" /></td>
    </tr>
    <tr>
     <td>Address</td>
     <td><input type="text" name="address" /></td>
    </tr>
    <tr>
     <td>Contact No</td>
     <td><input type="text" name="contact" /></td>
    </tr>
   </table>
   <input type="submit" value="Submit" />
  </form>
 </div>
</body>
</html>

Create an employeedetails.jsp

After an employee successfully registered then this page show a successful message on screen:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
 pageEncoding="ISO-8859-1"%>
<%@page import="net.javaguides.employeemanagement.dao.*"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
 <h1>User successfully registered!</h1>
</body>
</html>

6. Conclusion

In this tutorial, we’ve learned about the MVC i.e. Model View Controller architecture, and we focused on how to implement a simple example using JSP and Servlet.

Servlet + JSP + JDBC + MySQL Examples

Get source code of this tutorial on my GitHub Repository.

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