Hibernate Example using JPA and MySQL

Hibernate with JPA simplifies database interaction in Java by allowing developers to work with objects instead of writing complex SQL. It reduces boilerplate code and provides a standardized way to manage data persistence. Using MySQL with Hibernate ensures efficient and structured data storage.

• Maps Java classes directly to database tables
• Easily connects with MySQL using configuration
• Handles data operations reliably with JPA standards

Step-by-Step Implementation to use Jpa with Mysql database

Step 1: Create a Maven Project

Open your IDE (IntelliJ IDEA, Eclipse or STS). Create a New Maven Project.

• GroupId: org.example
• ArtifactId: hibernateapp
• Version: 1.0-SNAPSHOT

Step 2: Add Dependencies in pom.xml

We need Hibernate ORM and MySQL connector dependencies.

<dependency>

<groupId>org.hibernate.orm</groupId>

<artifactId>hibernate-core</artifactId>

<version>6.2.7.Final</version>

</dependency>

<dependency>

<groupId>mysql</groupId>

<artifactId>mysql-connector-java</artifactId>

<version>8.0.33</version>

</dependency>

Example: pom.xml File

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="https://maven.apache.org/POM/4.0.0"
         xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="https://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>hibernateapp</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>org.hibernate.orm</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>6.2.7.Final</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.33</version>
        </dependency>
    </dependencies>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
    </properties>

</project>

Step 3: Create Entity Class (Song.java)

Create a simple POJO class and name the class as Song. 

import jakarta.persistence.Column;
import jakarta.persistence.Entity;
import jakarta.persistence.Id;
import jakarta.persistence.Table;

@Entity
@Table(name = "song")

// POJO class
public class Song {

    @Id @Column(name = "songId") private int id;

    @Column(name = "songName") private String songName;

    @Column(name = "singer") private String artist;

    public int getId() { return id; }

    public void setId(int id) { this.id = id; }

    public String getSongName() { return songName; }

    public void setSongName(String songName)
    {
        this.songName = songName;
    }

    public String getArtist() { return artist; }

    public void setArtist(String artist)
    {
        this.artist = artist;
    }
}

Step 4: Configure Hibernate (hibernate.cfg.xml)

Create a hibernate configuration file (XML file) inside the src > main > resources folder. Here we have named the file hibernate.cfg.xml. In this file, we are going to configure all the properties for the MySQL Database.

hibernate.cfg.xml File 

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
    <session-factory>

        <!-- Database Connection -->
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernate_demo</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">your_password</property>
        <property name="hibernate.connection.driver_class">com.mysql.cj.jdbc.Driver</property>

        <!-- Hibernate Settings -->
        <property name="hibernate.show_sql">true</property>
        <property name="hibernate.format_sql">true</property>
        <property name="hibernate.hbm2ddl.auto">update</property> 

        <!-- Mapping Entity -->
        <mapping class="Song"/>
    </session-factory>
</hibernate-configuration>

Step 5: Create Main Class (App.java)

Create a class named App and inside the class write the main() method

Example:

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class App {

    public static void main(String[] args)
    {

        // Create Configuration
        Configuration configuration = new Configuration();
        configuration.configure("hibernate.cfg.xml");
        configuration.addAnnotatedClass(Song.class);

        // Create Session Factory and auto-close with try-with-resources.
        try (SessionFactory sessionFactory
                = configuration.buildSessionFactory()) {

            // Initialize Session Object
            Session session = sessionFactory.openSession();

            Song song1 = new Song();

            song1.setId(1);
            song1.setSongName("Broken Angel");
            song1.setArtist("Akon");

            session.beginTransaction();

            // Here we have used persist() method of JPA
            session.persist(song1);

            session.getTransaction().commit();
        }
    }
}

Step 6: Create Database Schema in MySQL

Create a schema named hibernate-demo (you can choose your own) inside your MySQL Database. And run your application.

Run the following command in MySQL Workbench or CLI:

CREATE DATABASE hibernate-demo;

Output:

After running the project, check MySQL Workbench

SELECT * FROM song;

We can see the data has been saved inside your MySQL workbench. And in the hibernate-demo schema, a table named song has been created and the corresponding values for each column that you have set in App.java class have been stored.