Delete Data from Database with Hibernate in JSP-Servlet

Create Database

Create a database with the name is learnjspservlet. This database have a table: Product

--
-- Table structure for table `product`
--

CREATE TABLE `product` (
  `id` int(11) NOT NULL PRIMARY KEY AUTO_INCREMENT,
  `name` varchar(250) NOT NULL,
  `price` double NOT NULL,
  `quantity` int(11) NOT NULL,
  `status` tinyint(1) NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1;

--
-- Dumping data for table `product`
--

INSERT INTO `product` (`name`, `price`, `quantity`, `status`) VALUES
('Name 1', 4.5, 10, 1),
('Name 2', 7, 2, 0),
('Name 3', 8, 4, 1);

Product Structure Table

Product Data Table

Create Maven Project

On the Eclipse, create a Maven project

Click Next button to select Workspace Location for project

Click Next button to select Archetype for project

Click Next button and enter Project Information:

• Group Id: LearnJSPServletWithRealApps
• Artifact Id: LearnJSPServletWithRealApps
• Package: com.demo

Click Finish button to finish create Maven project

Configure pom.xml

<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/maven-v4_0_0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>LearnJSPServletWithRealApps</groupId>
	<artifactId>LearnJSPServletWithRealApps</artifactId>
	<packaging>war</packaging>
	<version>0.0.1-SNAPSHOT</version>
	<name>Learn JSP-Servlet with Real Apps</name>
	<url>http://maven.apache.org</url>
	<dependencies>

		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>3.8.1</version>
			<scope>test</scope>
		</dependency>

		<dependency>
			<groupId>javax.servlet.jsp.jstl</groupId>
			<artifactId>javax.servlet.jsp.jstl-api</artifactId>
			<version>1.2.1</version>
		</dependency>

		<dependency>
			<groupId>taglibs</groupId>
			<artifactId>standard</artifactId>
			<version>1.1.2</version>
		</dependency>

		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>javax.servlet-api</artifactId>
			<version>3.1.0</version>
			<scope>provided</scope>
		</dependency>

		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>8.0.13</version>
		</dependency>

		<dependency>
			<groupId>org.hibernate</groupId>
			<artifactId>hibernate-core</artifactId>
			<version>5.4.0.CR1</version>
		</dependency>

		<dependency>
			<groupId>org.hibernate.common</groupId>
			<artifactId>hibernate-commons-annotations</artifactId>
			<version>5.1.0.Final</version>
		</dependency>

		<dependency>
			<groupId>org.hibernate.javax.persistence</groupId>
			<artifactId>hibernate-jpa-2.1-api</artifactId>
			<version>1.0.2.Final</version>
		</dependency>

		<dependency>
			<groupId>org.hibernate</groupId>
			<artifactId>hibernate-entitymanager</artifactId>
			<version>5.4.0.CR1</version>
		</dependency>

		<dependency>
			<groupId>org.hibernate</groupId>
			<artifactId>hibernate-validator</artifactId>
			<version>6.0.13.Final</version>
		</dependency>

		<dependency>
			<groupId>org.slf4j</groupId>
			<artifactId>slf4j-api</artifactId>
			<version>1.7.25</version>
		</dependency>

		<dependency>
			<groupId>com.sun.xml.bind</groupId>
			<artifactId>jaxb-impl</artifactId>
			<version>2.0.1</version>
		</dependency>

	</dependencies>
	<build>
		<finalName>LearnJSPServletWithRealApps</finalName>
	</build>
</project>

Configure web.xml

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
 	<welcome-file-list>
 		<welcome-file>index.jsp</welcome-file>
 	</welcome-file-list>
</web-app>

Redirect Page

Create new JSP file named index.jsp in src\main\webapp folder.

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
	pageEncoding="ISO-8859-1" isELIgnored="false"%>
<jsp:forward page="product"></jsp:forward>

Create Entities

Create new package named com.demo.entities. In this package, create new java class named Product.java as below:

package com.demo.entities;

import java.io.Serializable;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "product")
public class Product implements Serializable {

	private static final long serialVersionUID = 1L;

	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	private int id;
	private String name;
	private double price;
	private int quantity;
	private boolean status;

	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 double getPrice() {
		return price;
	}

	public void setPrice(double price) {
		this.price = price;
	}

	public int getQuantity() {
		return quantity;
	}

	public void setQuantity(int quantity) {
		this.quantity = quantity;
	}

	public boolean isStatus() {
		return status;
	}

	public void setStatus(boolean status) {
		this.status = status;
	}

}

Hibernate Configuration File

Create new xml file named hibernate.cfg.xml in src\main\java folder as below:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
                                         "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
	<session-factory>
		<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
		<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/learnjspservlet</property>
		<property name="hibernate.connection.username">root</property>
		<property name="hibernate.connection.password">123456</property>
		<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
		<property name="hibernate.current_session_context_class">thread</property>
		<mapping class="com.demo.entities.Product" />
	</session-factory>
</hibernate-configuration>

Create HibernateUtil Class

Create new package named com.demo.models. In this package, create new java class named HibernateUtil.java as below:

package com.demo.models;

import org.hibernate.SessionFactory;
import org.hibernate.boot.Metadata;
import org.hibernate.boot.MetadataSources;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;

public class HibernateUtil {

	private static final SessionFactory sessionFactory;

	static {
		try {
			StandardServiceRegistry standardRegistry = new StandardServiceRegistryBuilder()
					.configure("hibernate.cfg.xml").build();
			Metadata metaData = new MetadataSources(standardRegistry).getMetadataBuilder().build();
			sessionFactory = metaData.getSessionFactoryBuilder().build();
		} catch (Throwable th) {
			throw new ExceptionInInitializerError(th);
		}
	}

	public static SessionFactory getSessionFactory() {
		return sessionFactory;
	}
}

Create Models

Create new package named com.demo.models. In this package, create new java class named ProductModel.java as below:

package com.demo.models;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;

import com.demo.entities.Product;

public class ProductModel {

	protected SessionFactory sessionFactory = HibernateUtil.getSessionFactory();

	public List<Product> findAll() {
		List<Product> products = null;
		Session session = null;
		Transaction transaction = null;
		try {
			session = sessionFactory.openSession();
			transaction = session.beginTransaction();
			org.hibernate.query.Query<Product> query = session.createQuery("from Product", Product.class);
			products = query.getResultList();
			transaction.commit();
		} catch (Exception e) {
			if (transaction != null) {
				transaction.rollback();
			}
		} finally {
			session.close();
		}
		return products;
	}

	public Product find(int id) {
		Product product = null;
		Session session = null;
		Transaction transaction = null;
		try {
			session = sessionFactory.openSession();
			transaction = session.beginTransaction();
			org.hibernate.query.Query<Product> query = session.createQuery("from Product where id = :id", Product.class);
			query.setParameter("id", id);
			product = query.getSingleResult();
			transaction.commit();
		} catch (Exception e) {
			if (transaction != null) {
				transaction.rollback();
			}
		} finally {
			session.close();
		}
		return product;
	}

	public boolean delete(int id) {
		boolean result = true;
		Session session = null;
		Transaction transaction = null;
		try {
			session = sessionFactory.openSession();
			transaction = session.beginTransaction();
			session.delete(this.find(id));
			transaction.commit();
		} catch (Exception e) {
			if (transaction != null) {
				transaction.rollback();
			}
			result = false;
		} finally {
			session.close();
		}
		return result;
	}

}

Create Servlets

Create new package named com.demo.servlets. In this package, create new Servlets as below:

Product Servlet

In com.demo.servlets package, create new Servlet named ProductServlet as below:

package com.demo.servlets;

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 com.demo.models.ProductModel;

@WebServlet("/product")
public class ProductServlet extends HttpServlet {

	private static final long serialVersionUID = 1L;

	public ProductServlet() {
		super();
	}

	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		ProductModel productModel = new ProductModel();
		String action = request.getParameter("action");
		if (action == null) {
			request.setAttribute("products", productModel.findAll());
			request.getRequestDispatcher("product/index.jsp").forward(request, response);
		} else {
			if (action.equalsIgnoreCase("delete")) {
				int id = Integer.parseInt(request.getParameter("id"));
				productModel.delete(id);
				response.sendRedirect("product");
			}
		}
	}

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

}

Create JSP Pages

Create new folder named product in src\main\webapp folder. In this folder, create new JSP files as below:

Index Page

In src\main\webapp\product folder, create new JSP file named index.jsp as below:

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
	pageEncoding="ISO-8859-1" isELIgnored="false"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html>
<head>
<title>CRUD Operators with Hibernate</title>
</head>
<body>

	<h3>Product List</h3>
	<table border="1" cellpadding="2" cellspacing="2">
		<tr>
			<th>Id</th>
			<th>Name</th>
			<th>Status</th>
			<th>Price</th>
			<th>Quantity</th>
			<th>Action</th>
		</tr>
		<c:forEach var="product" items="${products }">
			<tr>
				<td>${product.id }</td>
				<td>${product.name }</td>
				<td>${product.status }</td>
				<td>${product.price }</td>
				<td>${product.quantity }</td>
				<td>
					<a href="${pageContext.request.contextPath }/product?action=delete&id=${product.id }">Delete</a>
				</td>
			</tr>
		</c:forEach>
	</table>

</body>
</html>

Structure of Maven Project

Run Application

Select project, right click and select Run As/Run on Server menu

Access DemoServlet with following urls as below:

• http://localhost:8081/LearnJSPServletWithRealApps
• http://localhost:8081/LearnJSPServletWithRealApps/product

Output

Click Delete link:

Output