Java Servlet and JSP CRUD Application Tutorial | Step-by-Step Guide to Build a Product Management System

Step-by-Step Guide to Building a Product Management System

In this comprehensive tutorial, we will walk through the process of building a simple Product Management System using Java Servlets and JSP (JavaServer Pages). This project will demonstrate the essential CRUD (Create, Read, Update, Delete) operations, enabling users to manage products in a MySQL database.

By the end of this tutorial, you’ll have a fully functional CRUD application that follows industry best practices, with clear explanations of each step involved.

Table of Contents

1. Introduction
2. Project Structure
3. Database Setup
4. Configuring Maven Dependencies
5. Creating the Database Utility Class
6. Defining the Product Model
7. Creating the Data Access Object (DAO)
8. Building the Product Servlet
9. Developing JSP Pages for CRUD Operations
10. Configuring web.xml
11. Running the Application
12. Summary

Introduction

What is a CRUD Application?

A CRUD (Create, Read, Update, Delete) application is a fundamental project in web development. It allows users to:

• Create new records in a database.
• Read and display existing records.
• Update and modify records.
• Delete records when no longer needed.

This tutorial uses Java Servlets and JSP, two of the most popular technologies in the Java ecosystem for building dynamic web applications. Our application will manage a list of products, each with the following attributes:

• ID (auto-incremented primary key)
• Name (product name)
• Description (details about the product)
• Price (product price)
• Color (product color)

Prerequisites

To follow this tutorial, you need the following:

• Java 17+
• Apache Tomcat Server (version 9 or later)
• MySQL Database
• Maven for dependency management
• Basic knowledge of Java, SQL, and HTML

1. Project Structure

Here’s the directory structure for the project:

servletcrud/
├── src/
│   ├── main/
│   │   ├── java/
│   │   │   └── acesoftech/
│   │   │       ├── DBUtil.java            <!-- Database utility -->
│   │   │       ├── Product.java           <!-- Product model -->
│   │   │       ├── ProductDAO.java        <!-- Data Access Object (DAO) -->
│   │   │       └── ProductServlet.java    <!-- Servlet for handling requests -->
│   │   └── webapp/
│   │       ├── WEB-INF/
│   │       │   └── web.xml                <!-- Web configuration -->
│   │       └── views/
│   │           ├── add-product.jsp        <!-- Add product form -->
│   │           ├── edit-product.jsp       <!-- Edit product form -->
│   │           └── product-list.jsp       <!-- Display product list -->
└── pom.xml                                 <!-- Maven configuration file -->

2. Database Setup

First, create a MySQL database to store product information:

CREATE DATABASE servletcrud;
USE servletcrud;

CREATE TABLE product (
id INT AUTO_INCREMENT PRIMARY KEY,
name VARCHAR(100) NOT NULL,
description VARCHAR(255),
price DECIMAL(10, 2) NOT NULL,
color VARCHAR(50)
);

This table will store the details of each product.

3. Configuring Maven Dependencies

Create a pom.xml file to manage the project dependencies:

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 
                             http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.acesoftech</groupId>
    <artifactId>servletcrud</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <!-- MySQL Connector -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.28</version>
        </dependency>

        <!-- Servlet API -->
        <dependency>
            <groupId>jakarta.servlet</groupId>
            <artifactId>jakarta.servlet-api</artifactId>
            <version>5.0.0</version>
            <scope>provided</scope>
        </dependency>

        <!-- JSP and JSTL -->
        <dependency>
            <groupId>jakarta.servlet.jsp.jstl</groupId>
            <artifactId>jakarta.servlet.jsp.jstl-api</artifactId>
            <version>2.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.web</groupId>
            <artifactId>jakarta.servlet.jsp.jstl</artifactId>
            <version>2.0.0</version>
        </dependency>
    </dependencies>
</project>

4. Creating the Database Utility Class

DBUtil.java manages the connection to the MySQL database:

package acesoftech;

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

public class DBUtil {
    private static final String URL = "jdbc:mysql://localhost:3306/servletcrud";
    private static final String USER = "root"; 
    private static final String PASSWORD = "password";

    public static Connection getConnection() throws SQLException {
        return DriverManager.getConnection(URL, USER, PASSWORD);
    }
}

5. Defining the Product Model

Product.java defines the properties of a product:

package acesoftech;

public class Product {
    private int id;
    private String name;
    private String description;
    private double price;
    private String color;

    // Getters and Setters
    public int getId() { return id; }
    public void setId(int id) { this.id = id; }
    public String getName() { return name; }
    public void setName(String name) { this.name = name; }
    public String getDescription() { return description; }
    public void setDescription(String description) { this.description = description; }
    public double getPrice() { return price; }
    public void setPrice(double price) { this.price = price; }
    public String getColor() { return color; }
    public void setColor(String color) { this.color = color; }
}

6. Creating the Data Access Object (DAO)

ProductDAO.java handles all database operations:

package acesoftech;

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

/**
 * Data Access Object (DAO) class for managing Product data.
 * This class provides methods to perform CRUD operations
 * on the 'product' table in the database.
 */
public class ProductDAO {

    /**
     * Adds a new product to the database.
     *
     * @param product the product to be added
     * @throws SQLException if a database error occurs
     */
    public void addProduct(Product product) throws SQLException {
        String sql = "INSERT INTO product (name, description, price, color) VALUES (?, ?, ?, ?)";
        try (Connection connection = DBUtil.getConnection();
             PreparedStatement statement = connection.prepareStatement(sql)) {
            statement.setString(1, product.getName());
            statement.setString(2, product.getDescription());
            statement.setDouble(3, product.getPrice());
            statement.setString(4, product.getColor());
            statement.executeUpdate();
        }
    }

    /**
     * Retrieves all products from the database.
     *
     * @return a list of all products
     * @throws SQLException if a database error occurs
     */
    public List<Product> getAllProducts() throws SQLException {
        List<Product> products = new ArrayList<>();
        String sql = "SELECT * FROM product";
        try (Connection connection = DBUtil.getConnection();
             Statement statement = connection.createStatement();
             ResultSet rs = statement.executeQuery(sql)) {
            while (rs.next()) {
                Product product = new Product();
                product.setId(rs.getInt("id"));
                product.setName(rs.getString("name"));
                product.setDescription(rs.getString("description"));
                product.setPrice(rs.getDouble("price"));
                product.setColor(rs.getString("color"));
                products.add(product);
            }
        }
        return products;
    }

    /**
     * Retrieves a product by its ID from the database.
     *
     * @param id the ID of the product
     * @return the product with the specified ID, or null if not found
     * @throws SQLException if a database error occurs
     */
    public Product getProductById(int id) throws SQLException {
        Product product = null;
        String sql = "SELECT * FROM product WHERE id = ?";
        try (Connection connection = DBUtil.getConnection();
             PreparedStatement statement = connection.prepareStatement(sql)) {
            statement.setInt(1, id);
            try (ResultSet rs = statement.executeQuery()) {
                if (rs.next()) {
                    product = new Product();
                    product.setId(rs.getInt("id"));
                    product.setName(rs.getString("name"));
                    product.setDescription(rs.getString("description"));
                    product.setPrice(rs.getDouble("price"));
                    product.setColor(rs.getString("color"));
                }
            }
        }
        return product;
    }

    /**
     * Updates an existing product in the database.
     *
     * @param product the product with updated data
     * @throws SQLException if a database error occurs
     */
    public void updateProduct(Product product) throws SQLException {
        String sql = "UPDATE product SET name = ?, description = ?, price = ?, color = ? WHERE id = ?";
        try (Connection connection = DBUtil.getConnection();
             PreparedStatement statement = connection.prepareStatement(sql)) {
            statement.setString(1, product.getName());
            statement.setString(2, product.getDescription());
            statement.setDouble(3, product.getPrice());
            statement.setString(4, product.getColor());
            statement.setInt(5, product.getId());
            statement.executeUpdate();
        }
    }

    /**
     * Deletes a product from the database.
     *
     * @param id the ID of the product to be deleted
     * @throws SQLException if a database error occurs
     */
    public void deleteProduct(int id) throws SQLException {
        String sql = "DELETE FROM product WHERE id = ?";
        try (Connection connection = DBUtil.getConnection();
             PreparedStatement statement = connection.prepareStatement(sql)) {
            statement.setInt(1, id);
            statement.executeUpdate();
        }
    }
}