Use UUID Generator in Hibernate 5

Java Libraries

Copy JAR files which are listed below:

antlr-2.7.7.jar
classmate-1.3.4.jar
commons-lang3-3.6.jar
commons-logging-1.1.3.jar
dom4j-1.6.1.jar
ehcache-core-2.6.11.jar
geolatte-geom-1.1.0.jar
hibernate-commons-annotations-5.0.1.Final.jar
hibernate-core-5.2.11.Final.jar
hibernate-ehcache-5.2.12.Final.jar
hibernate-ejb3-persistence.jar
hibernate-enhance-maven-plugin-4.3.7.Final.jar
hibernate-entitymanager.jar
hibernate-java8-5.2.11.Final.jar
hibernate-jpa-2.1-api-1.0.0.Final.jar
hibernate-spatial-5.2.11.Final.jar
hibernate-validator-6.0.2.Final.jar
javassist-3.16.1-GA.jar
jboss-logging-3.3.1.Final.jar
jboss-transaction-api_1.1_spec-1.0.1.Final.jar
jts-1.11.jar
mysql-connector-java-5.1.36.jar
slf4j-api-1.7.21.jar

Create Database

Create a database with the name is hibernate5. This database have a table: Student table.

--
-- Table structure for table `student`
--

CREATE TABLE `student` (
  `id` binary(16) NOT NULL,
  `name` varchar(250) NOT NULL,
  `email` varchar(250) NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1;

--
-- Dumping data for table `student`
--

INSERT INTO `student` (`id`, `name`, `email`) VALUES
(0xa77df760507d40b5a6d341b2d1eb3ead, 'Student 2', 'student1@gmail.com');

INSERT INTO `student` (`id`, `name`, `email`) VALUES(0x72f792c710bf430e9e07be4f8b29b71e, 'Student 1', 'student1@gmail.com');

INSERT INTO `student` (`id`, `name`, `email`) VALUES(0x04c8a9da59e54228a3383c0108037551, 'Student 3', 'student1@gmail.com');

Structures of Student Table

Student Table

Entities Class

Create a entity class – Student.java to represent the above table

Student.java

package entities;

import java.util.UUID;
import javax.persistence.*;
import org.hibernate.annotations.GenericGenerator;

@Entity
@Table(name = "student")
public class Student implements java.io.Serializable {

	@Id
	@GenericGenerator(name = "uuid2", strategy = "uuid2")
	@GeneratedValue(generator = "uuid2")
	private UUID id;

	@Column
	private String name;

	@Column
	private String email;

	public UUID getId() {
		return id;
	}

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

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getEmail() {
		return email;
	}

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

}

Hibernate Configuration File

Puts Student.java in your Hibernate configuration file, and also MySQL connection details.

<?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.enable_lazy_load_no_trans">true</property>
		<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
		<property name="hibernate.connection.password">123456</property>
		<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernate5</property>
		<property name="hibernate.connection.username">root</property>
		<property name="hibernate.dialect">org.hibernate.spatial.dialect.mysql.MySQLSpatialDialect</property>
		<property name="hibernate.current_session_context_class">thread</property>
		<mapping class="entities.Student" />
	</session-factory>
</hibernate-configuration>

Create HibernateUtil class

The HibernateUtil class helps in creating the SessionFactory from the Hibernate configuration file. The SessionFactory is threadsafe, so it is not necessary to obtain one for each thread.

package id_generation;

import org.hibernate.*;
import org.hibernate.boot.*;
import org.hibernate.boot.registry.*;

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 StudentModel class

The StudentModel class contains methods to interact with the database.

package id_generation;

import java.util.List;
import java.util.UUID;
import org.hibernate.*;
import entities.*;

public class StudentModel {

	private SessionFactory sessionFactory = HibernateUtil.getSessionFactory();

	public Boolean create(Student student) {
		Boolean result = true;
		Session session = null;
		Transaction transaction = null;
		try {
			session = sessionFactory.openSession();
			transaction = session.beginTransaction();
			session.save(student);
			transaction.commit();
		} catch (Exception e) {
			result = false;
			if (transaction != null) {
				transaction.rollback();
			}
		} finally {
			session.close();
		}
		return result;
	}

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

	public Student findById(UUID id) {
		Student student = null;
		Session session = null;
		Transaction transaction = null;
		try {
			session = sessionFactory.openSession();
			transaction = session.beginTransaction();
			org.hibernate.query.Query query = session.createQuery("from Student where id = :id");
			query.setParameter("id", id);
			student = (Student) query.uniqueResult();
			transaction.commit();
		} catch (Exception e) {
			student = null;
			if (transaction != null) {
				transaction.rollback();
			}
		} finally {
			session.close();
		}
		return student;
	}

}

Run It

package id_generation;

import java.util.UUID;
import entities.Student;

public class Main {

	public static void main(String[] args) {

		StudentModel studentModel = new StudentModel();

		System.out.println("Add New Student");
		Student newStudent = new Student();
		newStudent.setId(UUID.randomUUID());
		newStudent.setName("Student 4");
		newStudent.setEmail("student1@gmail.com");
		System.out.println(studentModel.create(newStudent));

		System.out.println("List All Student");
		for(Student student : studentModel.findAll()) {
			System.out.println("Id: " + student.getId());
			System.out.println("Name: " + student.getName());
			System.out.println("Email: " + student.getEmail());
			System.out.println("==================");
		}

		System.out.println("Find Student By Id");
		Student studentInfo = studentModel.findById(UUID.fromString("a77df760-507d-40b5-a6d3-41b2d1eb3ead"));
		System.out.println("Id: " + studentInfo.getId());
		System.out.println("Name: " + studentInfo.getName());
		System.out.println("Email: " + studentInfo.getEmail());


	}

}

Output

Add New Student
true

List All Student
Id: a77df760-507d-40b5-a6d3-41b2d1eb3ead
Name: Student 2
Email: student1@gmail.com
==================
Id: 72f792c7-10bf-430e-9e07-be4f8b29b71e
Name: Student 1
Email: student1@gmail.com
==================
Id: 04c8a9da-59e5-4228-a338-3c0108037551
Name: Student 3
Email: student1@gmail.com
==================
Id: 4295ed9e-4f3f-4109-9905-8666d5b65019
Name: Student 4
Email: student1@gmail.com
==================

Find Student By Id
Id: a77df760-507d-40b5-a6d3-41b2d1eb3ead
Name: Student 2
Email: student1@gmail.com