Hibernate is an object-relational mapping (ORM) library for the Java language, providing a framework for mapping an object-oriented domain model to a traditional relational database. This means you are not required to build and execute SQL queries for interaction with database. You just have to instruct hibernate for that by calling hibernate APIs and hibernate will create and execute those SQL queries on behalf of you.
In this hibernate tutorial, I am giving example of inserting data in a single table. We have an object in application i.e. Employee
. We want to store it in database. Employee
class has following attributes:
- employee id – Integer
- email – String
- first name – String
- last name – String
It can have more fields, but I am taking only four to make example concrete.
1. Hibernate entity class
Hibernate talks with Java POJO classes which are marked as hibernate entities. To convert a Java class into entity, we need to apply @Entity annotation on it. There are other hibernate annotations like @Table, @Column and @Id etc which help in mapping entity fields to database table and columns.
Employee
entity class looks like below after applying the annotations.
@Entity @Table(name = "EMPLOYEE", uniqueConstraints = { @UniqueConstraint(columnNames = "ID"), @UniqueConstraint(columnNames = "EMAIL") }) public class EmployeeEntity implements Serializable { private static final long serialVersionUID = -1798070786993154676L; @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name = "ID", unique = true, nullable = false) private Integer id; @Column(name = "EMAIL", unique = true, nullable = false, length = 100) private String email; @Column(name = "FIRST_NAME", unique = false, nullable = false, length = 100) private String firstName; @Column(name = "LAST_NAME", unique = false, nullable = false, length = 100) private String lastName; //Getters and setters }
2. Hibernate configuration
Next step is to configure hibernate in “hibernate.cgf.xml” file. This file contains all available entities in system and database connection meta-data.
<?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/hibernatedemo</property> <property name="hibernate.connection.password">password</property> <property name="hibernate.connection.username">root</property> <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property> <property name="show_sql">true</property> <property name="hbm2ddl.auto">create</property> <mapping class="hibernate.test.dto.EmployeeEntity"></mapping> </session-factory> </hibernate-configuration>
3. Hibernate SessionFactory
Now hibernate configuration is on place, we have to build the hibernate session factory. Session factory is used to obtain the connection of database and various activities like commit and rollback.
public class HibernateUtil { private static final SessionFactory sessionFactory = buildSessionFactory(); private static SessionFactory buildSessionFactory() { try { // Create the SessionFactory from hibernate.cfg.xml return new AnnotationConfiguration().configure(new File("hibernate.cgf.xml")).buildSessionFactory(); } catch (Throwable ex) { // Make sure you log the exception, as it might be swallowed System.err.println("Initial SessionFactory creation failed." + ex); throw new ExceptionInInitializerError(ex); } } public static SessionFactory getSessionFactory() { return sessionFactory; } public static void shutdown() { // Close caches and connection pools getSessionFactory().close(); } }
4. Hibernate insert query example
Finally we will use this hibernate session factory to execute insert query to save employee in database.
public class TestHibernateInsert { public static void main(String[] args) { Session session = HibernateUtil.getSessionFactory().openSession(); session.beginTransaction(); //Add new Employee object EmployeeEntity emp = new EmployeeEntity(); emp.setEmail("lokesh@mail.com"); emp.setFirstName("lokesh"); emp.setLastName("gupta"); //Save the employee in database session.save(emp); //Commit the transaction session.getTransaction().commit(); HibernateUtil.shutdown(); } }
Program logs.
Hibernate: insert into EMPLOYEE (EMAIL, FIRST_NAME, LAST_NAME) values (?, ?, ?)
Lets verify the data in database.

5. Troubleshooting
- Please ensure to add hibernate and mysql driver dependencies in project. In maven these are as below:
<dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-commons-annotations</artifactId> <version>3.0.0.ga</version> </dependency> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-annotations</artifactId> <version>3.3.0.ga</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.6</version> </dependency>
- Verify that
hibernate.cgf.xml
file is present and has valid database meta-data.
Happy Learning !!
Hi Lokesh,
is it possible using entityManager?
Initial SessionFactory creation failed.java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory
Exception in thread “main” java.lang.ExceptionInInitializerError
at hibernateutil.HibernateUtil.buildSessionFactory(HibernateUtil.java:22)
at hibernateutil.HibernateUtil.(HibernateUtil.java:10)
at hibernatetesinsert.TestHibernateInsert.main(TestHibernateInsert.java:12)
Caused by: java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory
at org.hibernate.cfg.Configuration.(Configuration.java:120)
at hibernateutil.HibernateUtil.buildSessionFactory(HibernateUtil.java:17)
… 2 more
Caused by: java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
… 4 more
i am getting above error
Add apache commons logging (link) to classpath.
how to connect front end to hibernate
Hi ,
Can you tell how to write inner join in criteria.
Sir this is not Hibernate insert query example here u are just inserting data using setter method of modal class .
hibernate insert query is different.