Hibernate Example using Annotation in Eclipse

The hibernate application can be created with annotation. There are many annotations that can be used to create hibernate application such as @Entity, @Id, @Table etc.

Hibernate Annotations are based on the JPA 2 specification and supports all the features.

All the JPA annotations are defined in the javax.persistence package. Hibernate EntityManager implements the interfaces and life cycle defined by the JPA specification.

The core advantage of using hibernate annotation is that you don't need to create mapping (hbm) file. Here, hibernate annotations are used to provide the meta data.

Example to create the hibernate application with Annotation

Here, we are going to create a maven based hibernate application using annotation in eclipse IDE. For creating the hibernate application in Eclipse IDE, we need to follow the below steps:

1) Create the Maven Project

To create the maven project left click on File Menu - New- Maven Project.

The new maven project opens in your eclipse. Click Next.

Now, select catalog type: internal and maven archetype - quickstart of 1.1 version. Then, click next.

Now, specify the name of Group Id and Artifact Id. The Group Id contains package name (e.g. com.javatpoint) and Artifact Id contains project name (e.g. HibernateAnnotation). Then click Finish.

2) Add project information and configuration in pom.xml file.

Open pom.xml file and click source. Now, add the below dependencies between <dependencies>....</dependencies> tag. These dependencies are used to add the jar files in Maven project.

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-core</artifactId>
    <version>5.3.1.Final</version>
</dependency>
	
<dependency>
    <groupId>com.oracle</groupId>
    <artifactId>ojdbc14</artifactId>
    <version>10.2.0.4.0</version>
</dependency>

Due to certain license issues, Oracle drivers are not present in public Maven repository. We can install it manually. To install Oracle driver into your local Maven repository, follow the following steps:

Install Maven
Run the command : install-file -Dfile=Path/to/your/ojdbc14.jar -DgroupId=com.oracle -DartifactId=ojdbc14 -Dversion=12.1.0 -Dpackaging=jar

3) Create the Persistence class.

Here, we are creating the same persistent class which we have created in the previous topic. But here, we are using annotation.

@Entity annotation marks this class as an entity.

@Table annotation specifies the table name where data of this entity is to be persisted. If you don't use @Table annotation, hibernate will use the class name as the table name by default.

@Id annotation marks the identifier for this entity.

@Column annotation specifies the details of the column for this property or field. If @Column annotation is not specified, property name will be used as the column name by default.

To create the Persistence class, right click on src/main/java - New - Class - specify the class name with package - finish.

Employee.java

package com.javatpoint.mypackage;

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

@Entity
@Table(name= "emp500") 
public class Employee {  

@Id	
private int id;  
private String firstName,lastName;  
  
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;  
}  
} 

4) Create the Configuration file

To create the configuration file, right click on src/main/java - new - file - specify the file name (e.g. hibernate.cfg.xml) - Finish.

hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
		"-//Hibernate/Hibernate Configuration DTD 5.3//EN"
		"http://www.hibernate.org/dtd/hibernate-configuration-5.3.dtd">
<hibernate-configuration>
    <session-factory>
          
    <property name="hbm2ddl.auto">update</property>  
        <property name="dialect">org.hibernate.dialect.Oracle9Dialect</property>  
        <property name="connection.url">jdbc:oracle:thin:@localhost:1521:xe</property>  
        <property name="connection.username">system</property>  
        <property name="connection.password">jtp</property>  
        <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property> 
     
        <mapping class="com.javatpoint.mypackage.Employee"/>
    </session-factory>
</hibernate-configuration>

5) Create the class that retrieves or stores the persistent object.

StoreData.java

package com.javatpoint.mypackage;  
  
import org.hibernate.Session;  
import org.hibernate.SessionFactory;  
import org.hibernate.Transaction;
import org.hibernate.boot.Metadata;
import org.hibernate.boot.MetadataSources;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;

  
public class StoreData {  
public static void main(String[] args) {  
      
	StandardServiceRegistry ssr = new StandardServiceRegistryBuilder().configure("hibernate.cfg.xml").build();
    Metadata meta = new MetadataSources(ssr).getMetadataBuilder().build();

SessionFactory factory = meta.getSessionFactoryBuilder().build();
Session session = factory.openSession();
Transaction t = session.beginTransaction(); 
          
    Employee e1=new Employee();  
    e1.setId(101);  
    e1.setFirstName("Gaurav");  
    e1.setLastName("Chawla");  
      
    session.save(e1);
	t.commit();
    System.out.println("successfully saved");  
	factory.close();
    session.close();  
      
}  
} 