Hibernate Java Configuration without XML Example in Eclipse using Maven

In this Hibernate example, we will learn how to create a simple Hibernate application using Java-based configuration without XML configuration in Eclipse IDE. We use Maven as a build tool and MySQL database to store the data.

Hibernate is an object-relational mapping framework for the Java language. It provides a framework for mapping an object-oriented domain model to a relational database. Object-relational mapping (ORM) is a programming technique for converting data between incompatible type systems in object-oriented programming languages.

Development Steps

1. Create a Simple Maven Project
2. Project Directory Structure
3. Add jar Dependencies to pom.xml
4. Creating the JPA Entity Class(Persistent class)
5. Create a Hibernate Java-based configuration file - HibernateUtil.java
6. Create StudentDao class
7. Create the Main class and Run an Application

1. Create a Simple Maven Project

Use How to Create a Simple Maven Project in Eclipse article to create a simple Maven project in Eclipse IDE.

2. Project Directory Structure

The project directory structure for your reference - 

3. Add jar Dependencies to 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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>net.javaguides</groupId>
    <artifactId>hibernate-java-config-example</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <dependencies>
        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.13</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-core -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.3.7.Final</version>
        </dependency>
    </dependencies>
</project>

4. Creating the JPA Entity Class(Persistent class)

Let's create a Student persistent class that is mapped to a student database table:

package net.javaguides.hibernate.entity;

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

@Entity
@Table(name = "student")
public class Student {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private int id;

    @Column(name = "first_name")
    private String firstName;

    @Column(name = "last_name")
    private String lastName;

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

    public Student() {

    }

    public Student(String firstName, String lastName, String email) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.email = email;
    }

    public int getId() {
        return id;
    }

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

    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 getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}

5. Create a Hibernate Java-based configuration file - HibernateUtil.java

Note that we are creating Hibernate Application using Java configuration without using hibernate.cfg.xml to connect the MySQL database.

package net.javaguides.hibernate.util;


import java.util.Properties;

import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.cfg.Environment;
import org.hibernate.service.ServiceRegistry;

import net.javaguides.hibernate.model.Student;

public class HibernateUtil {
    private static SessionFactory sessionFactory;
    public static SessionFactory getSessionFactory() {
        if (sessionFactory == null) {
            try {
                Configuration configuration = new Configuration();

                // Hibernate settings equivalent to hibernate.cfg.xml's properties
                Properties settings = new Properties();
                settings.put(Environment.DRIVER, "com.mysql.cj.jdbc.Driver");
                settings.put(Environment.URL, "jdbc:mysql://localhost:3306/java_dmeo?useSSL=false");
                settings.put(Environment.USER, "root");
                settings.put(Environment.PASS, "root");
                settings.put(Environment.DIALECT, "org.hibernate.dialect.MySQL5Dialect");

                settings.put(Environment.SHOW_SQL, "true");

                settings.put(Environment.CURRENT_SESSION_CONTEXT_CLASS, "thread");

                settings.put(Environment.HBM2DDL_AUTO, "create-drop");

                configuration.setProperties(settings);

                configuration.addAnnotatedClass(Student.class);

                ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
                    .applySettings(configuration.getProperties()).build();

                sessionFactory = configuration.buildSessionFactory(serviceRegistry);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return sessionFactory;
    }
}

6. Create StudentDao Class

Let's create a separate StudentDao class to separate out hibernate related stuff.

package net.javaguides.hibernate.dao;

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

import net.javaguides.hibernate.model.Student;
import net.javaguides.hibernate.util.HibernateUtil;

public class StudentDao {
    public void saveStudent(Student student) {

        Transaction transaction = null;

        // auto close session object
        try (Session session = HibernateUtil.getSessionFactory().openSession()) {

            // start the transaction
            transaction = session.beginTransaction();

            // save student object
            session.save(student);

            // commit transction
            transaction.commit();
        } catch (Exception e) {
            if (transaction != null) {
                transaction.rollback();
            }
        }
    }
}

7. Create the Main class and Run an Application

Let's test Hibernate application to connect MySQL database.

package net.javaguides.hibernate;

import net.javaguides.hibernate.dao.StudentDao;
import net.javaguides.hibernate.model.Student;

public class App {
    public static void main(String[] args) {

        StudentDao studentDao = new StudentDao();

        Student student = new Student("Ramesh", "Fadatare", "ramesh@gmail.com");
        studentDao.saveStudent(student);

        System.out.println(student.getId());
    }
}

Output

References

• https://www.javaguides.net/p/hibernate-tutorial.html

• https://www.javaguides.net/2018/11/hibernate-5-java-configuration-example.html