Saturday, August 27, 2011

Hibernate Annotations with Collections (List)

Following class illustrates how to model a java.util.List in hibernate with annotations. The subjects that a student takes are given in a list. So the 'Student' class is having an instance of List of String's. This can only be used to model collections of Java built-in types.
 
package com.shyarmal.hibernate;

import java.util.List;

import javax.persistence.Column;
import javax.persistence.ElementCollection;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;

@Entity
public class Student {

    private Long id;
    private String college;
    private List<String> subjects;

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    public Long getId() {
        return id;
    }
   
    public void setId(Long id) {
        this.id = id;
    }

    @Column(name = "college")
    public String getCollege() {
        return college;
    }

    public void setCollege(String college) {
        this.college = college;
    }
   
    @ElementCollection(fetch = FetchType.LAZY)
    @JoinTable(name = "student_subjects",
       joinColumns = {@JoinColumn(name = "student_id")})
    public List<String> getSubjects() {
        return subjects;
    }

    public void setSubjects(List<String> subjects) {
        this.subjects = subjects;
    }
}


Annotations used to handle the scenario;
  • @ElementCollection:- Informs that the instance annotated should be considered as a Java collection type. The optional attribute 'fetch' may be given to stress how the collection should be loaded [either lazy (the default) or eager]
  • @JoinTable:- Used to explicitly specify the properties of the table which joins the collection data with the entity in concern. Name of the joining column also can be given, which links to the primary key of the entity. Inverse joining column attribute should not be specified in this case.

thanks,
Shyarmal.

Hibernate Inheritance with Annotations

 There are a few approaches to deal with inheritance in hibernate. The technique discussed in this post accommodates all in one table.
  I'm having an abstract class, 'Person' and two of it's subclasses, 'Student' and 'Employee'. Both 'Student' and 'Employee' information is to be stored in a single table, named 'person'.

==================================================================
package com.shyarmal.hibernate;

import javax.persistence.Column;
import javax.persistence.DiscriminatorColumn;
import javax.persistence.DiscriminatorType;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Inheritance;
import javax.persistence.InheritanceType;
import javax.persistence.Table;

@Entity
@Table(name = "person")
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name = "person_type", discriminatorType = DiscriminatorType.STRING)
public abstract class Person {

    private Long id;
    protected String nic;
    protected int age;
    protected String name;
    protected char sex;

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    public Long getId() {
        return id;
    }
   
    public void setId(Long id) {
        this.id = id;
    }
   
    @Column(name = "nic", unique = true, nullable =false)
    public String getNic() {
        return nic;
    }

    public void setNic(String nic) {
        this.nic = nic;
    }

    @Column(name = "age")
    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Column(name = "name", nullable = false, length = 30)
    public String getName() {
        return name;
    }

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

    @Column(name = "gender", length = 2, nullable = false)
    public char getSex() {
        return sex;
    }

    public void setSex(char sex) {
        this.sex = sex;
    }
}

===================================================================

  First, we'll have a look at the 'Person' class. Here I'll only discuss what's done to accomplish inheritance [For other basic information, refer to Hinernate Annotations Example].  The annotation, @Inheritance denotes inheritance and there are subclasses of person to be mapped. Moreover all 'Person' instances will be available in a single database table, since the inheritance strategy used is  'InheritanceType.SINGLE_TABLE'.   
   @DiscriminatorColumn is mandatory in this approach. It forms a new column in the database with the name specified in the 'name' attribute. The discriminator column is used to Identify the type of the record (in our example where a record is of type 'Student' or 'Employee'). The attribute 'discriminatorType' states the type of the discriminator column.
   I have posted my 'Student' and 'Employee' classes below.

=================================================================== 
package com.shyarmal.hibernate;

import java.util.List;

import javax.persistence.Column;
import javax.persistence.DiscriminatorValue;
import javax.persistence.ElementCollection;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;

@Entity
@DiscriminatorValue("student")
public class Student extends Person {

    private String college;
    private List<String> subjects;

    @Column(name = "college", nullable = false, columnDefinition = "varchar(20) default 'unknown'")
    public String getCollege() {
        return college;
    }

    public void setCollege(String college) {
        this.college = college;
    }
   
    @ElementCollection(fetch = FetchType.LAZY)
    @JoinTable(name = "student_subjects", joinColumns = {@JoinColumn(name = "person_id")})
    public List<String> getSubjects() {
        return subjects;
    }

    public void setSubjects(List<String> subjects) {
        this.subjects = subjects;
    }

    @Override
    public String toString() {
        return String.format("student: nic [%s], college [%s], name [%s], age [%d]", nic, college, name, age);
    }
}

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

package com.shyarmal.hibernate;

import javax.persistence.Column;
import javax.persistence.DiscriminatorValue;
import javax.persistence.Entity;

@Entity
@DiscriminatorValue("employee")
public class Employee extends Person {

    private String company;
    private double salary;

    @Column(name = "company", nullable = false, columnDefinition = "varchar(20) default 'unknown'")
    public String getCompany() {
        return company;
    }

    public void setCompany(String company) {
        this.company = company;
    }

    @Column(name = "salary", nullable = false, columnDefinition = "double(8, 2) default '0.0'")
    public double getSalary() {
        return salary;
    }

    public void setSalary(double salary) {
        this.salary = salary;
    }

    @Override
    public String toString() {
        return String.format("employee: nic [%s], company [%s], name [%s], age [%d]", nic, company, name, age);
    }
}
===================================================================

@DiscriminatorValue annotation should be present in the subclasses. The discriminator value is what's saved in the discriminator column, which was discussed above [in our example if an employee is saved the discriminator column will have the value 'employee' and for a student the value will be 'student']. Notice 'columnDefinition' attribute in @Column in subclasses. If a column is declared not to be nullable, then a default value for the corresponding field should be given as done in the example. If not hibernate does not create the table. 'Student' class has a list of subjects. The methodology used is described here.

Below is the hibernate.cfg.xml used.
=================================================================== 

<?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="connection.url">jdbc:mysql://localhost/test</property>
        <property name="connection.username">root</property>
        <property name="connection.password">123</property>
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="show_sql">true</property>
        <property name="format_sql">true</property>
        <property name="hbm2ddl.auto">create</property>
        <property name="connection.pool_size">1</property>
        <property name="current_session_context_class">thread</property>
        <mapping class="com.shyarmal.hibernate.Person"/>
        <mapping class="com.shyarmal.hibernate.Student"/>
        <mapping class="com.shyarmal.hibernate.Employee"/> 
    </session-factory>
</hibernate-configuration>


thanks,
Shyarmal.

Hibernate annotations with enums

    How enums can be dealt using annotations is described here. In the example there are two enums, 'Status' and 'Priority', which are instances of the class, 'Batch'. 'Batch' is a domain class.

===================================================================

package com.shyarmal.hibernate;

public enum Status {

    STARTED, SUSPENDED, FINISHED, ABANDON
}


>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

package com.shyarmal.hibernate;

public enum Priority {

    HIGH, MEDIUM, LOW
}
===================================================================

   'Batch' is annotated as an entity and it's instances will be saved to a table called 'batch' in the database. @Enumerated annotation is used to mark a filed as an enum. Here the EnumType of 'Priority' is ORDINAL and hence an integer will be saved in the database which corresponds to it's actual value. Integers will be assigned to the enum values in the ascending order, starting with 0. As the EnumType of 'Status' is STRING, the values of it will be saved as varchar in the database.
===================================================================

package com.shyarmal.hibernate;

import javax.persistence.Entity;
import javax.persistence.EnumType;
import javax.persistence.Enumerated;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "batch")
public class Batch {

    private Long id;
    private Status status;
    private Priority priority;

    @Id
    @GeneratedValue
    public Long getId() {
        return id;
    }

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

    @Enumerated(value = EnumType.STRING)
    public Status getStatus() {
        return status;
    }

    public void setStatus(Status status) {
        this.status = status;
    }

    @Enumerated(value = EnumType.ORDINAL)
    public Priority getPriority() {
        return priority;
    }

    public void setPriority(Priority priority) {
        this.priority = priority;
    }

    @Override
    public String toString() {
        return String.format("batch: priority [%s], status [%s]", priority.name(), status.name());
    }

}

===================================================================

Following are some CRUD functions performed on 'Batch'.
===================================================================
// saving a batch
private static void save() {
        Transaction transaction = null;
        try {
            Session session = HibernateUtil.getSessionFactory().getCurrentSession();
            transaction = session.beginTransaction();
            Batch batch = new Batch();
            batch.setPriority(Priority.HIGH);
            batch.setStatus(Status.STARTED);
            session.save(batch);
            transaction.commit();
        } catch(Exception e) {
            transaction.rollback();
            e.printStackTrace();
        }
    }
   
// find one batch by the id.
private static void find() {
    Transaction transaction = null;
     try {
         Session session = HibernateUtil.getSessionFactory().getCurrentSession();
         transaction = session.beginTransaction();
         Batch batch = (Batch) session.get(Batch.class, new Long(1)); // batch with the id 1.
         transaction.commit();
     } catch(Exception e) {
         transaction.rollback();
         e.printStackTrace();
     }
}
   
// editing a batch 
private static void edit() {
     Transaction transaction = null;
      try {
         Session session = HibernateUtil.getSessionFactory().getCurrentSession();
         transaction = session.beginTransaction();
         Batch batch = (Batch) session.get(Batch.class, new Long(1));
         batch.setPriority(Priority.LOW);
         batch.setStatus(Status.SUSPENDED);
         transaction.commit();
      } catch(Exception e) {
         transaction.rollback();
         e.printStackTrace();
      }
}
   
// deleting a batch
private static void delete() {
   Transaction transaction = null;
    try {
        Session session = HibernateUtil.getSessionFactory().getCurrentSession();
        transaction = session.beginTransaction();
        session.delete(session.get(Batch.class, new Long(1)));
        transaction.commit();
    } catch(Exception e) {
        transaction.rollback();
        e.printStackTrace();
     }
}

===================================================================

Hibernate configuration file used is below. Notice the mapping, '<mapping class="com.shyarmal.hibernate.Batch"/>'.
===================================================================
<?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="connection.url">jdbc:mysql://localhost/test</property>
        <property name="connection.username">danuka</property>
        <property name="connection.password">123</property>
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="show_sql">true</property>
        <property name="format_sql">true</property>
        <property name="hbm2ddl.auto">create</property>
        <property name="connection.pool_size">1</property>
        <property name="current_session_context_class">thread</property>
        <mapping class="com.shyarmal.hibernate.Batch"/> 
    </session-factory>
</hibernate-configuration>

===================================================================
A sample record in the database.
mysql> select * from batch;
+----+----------+-------------+
| id | priority | status        |
+----+----------+-------------+
|  1 |        0 | FINISHED   |
+----+----------+-------------+
1 row in set (0.00 sec)


thanks,
Shyarmal.

Thursday, August 25, 2011

Hibernate annotations one-to-many and component

  This example is based on my previous post [Hibernate Annotations Example]. Previously an entity car was modeled to the database. Now in addition to that, an entity, car sale is to be mapped to the database, which has a one-to-many relationship with the entity, car. Moreover the address of the car sale is considered as a component of the same. Therefore we need to have two more modelling classes 'Sale' and 'Address'.
   The hibernate.cfg.xml file needs to be updated with 2 mapping elements (sub-elements of session-factory),
       <mapping class="com.shyarmal.hibernate.Sale"/>
   <mapping class="com.shyarmal.hibernate.Address"/>

   The only change done to the class, 'Car' from the previous example is changing the column name 'id' of the database table, 'cars' to 'car_id' .
===================================================================

package com.shyarmal.hibernate;

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

@Entity
@Table(name="cars")
public class Car {

    private Long id;
    private String make;
    private String brand;
    private String model;
    private double capacity;
    private double price;

    @Id
    @GeneratedValue
    @Column(name = "car_id")
    public Long getId() {
        return id;
    }

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

    public String getMake() {
        return make;
    }

    public void setMake(String make) {
        this.make = make;
    }

    public String getBrand() {
        return brand;
    }

    public void setBrand(String brand) {
        this.brand = brand;
    }

    public String getModel() {
        return model;
    }

    public void setModel(String model) {
        this.model = model;
    }

    public double getCapacity() {
        return capacity;
    }

    public void setCapacity(double capacity) {
        this.capacity = capacity;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

}

===================================================================

   An instance of the class, 'Address' is supposed to hold the address of a sale. So 'Sale' is in uni-directional association with 'Address'.  i.e. 'Address' is a component of Sale. Therefore it's annotated with  @Embeddable.
===================================================================

package com.shyarmal.hibernate;

import javax.persistence.Column;
import javax.persistence.Embeddable;
import javax.persistence.Table;

@Embeddable
public class Address {

    private String number;
    private String street;
    private String city;

    public Address() {
       
    }
   
    public Address(String number, String street, String city) {
        this.number = number;
        this.street = street;
        this.city = city;
    }
   
    @Column(name = "no", nullable = false, length = 10)
    public String getNumber() {
        return number;
    }

    public void setNumber(String number) {
        this.number = number;
    }

    @Column(name = "street", nullable = false, length = 50)
    public String getStreet() {
        return street;
    }

    public void setStreet(String street) {
        this.street = street;
    }

    @Column(name = "city", nullable = false, length = 50)
    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

}

===================================================================

   Records of the car sale will be saved in a table named, 'car_sale' in the mysql database. The address filed of Sale is annotated with  @Embedded, so that all the fields of the 'Address' instance set to 'Sale' will be saved in the table 'car_sale'. This is known as component mapping.
   'Sale' is having a one-to-many relationship with 'Car' and hence it has a set of 'Car' instances whose getter is annotated with @OneToMany(cascade = CascadeType.ALL). Further any change made to a 'sale' record will be cascaded to it's 'car' records. A joining table, 'sales_car_join' is used to link the cars with the sales (name attribute of @JoinTable) in this example. The 'joinColumns' attribute of @JoinTable specifies which field of 'Sale' should be used in the relationship and 'inverseJoinColumns' the field of 'Car'.
===================================================================

package com.shyarmal.hibernate;

import java.util.Set;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Embedded;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.OneToMany;
import javax.persistence.Table;

@Entity
@Table(name = "car_sale")
public class Sale {

    private Long id;
    private Set<Car> cars;
    private Address address;
    private String name;

    @Id
    @GeneratedValue
    @Column(name = "sale_id")
    public Long getId() {
        return id;
    }

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

    @OneToMany(cascade = CascadeType.ALL)
    @JoinTable(name = "sales_car_join",
            joinColumns = {@JoinColumn(name = "sale_id")},
            inverseJoinColumns = {@JoinColumn(name = "car_id")})
    public Set<Car> getCars() {
        return cars;
    }

    public void setCars(Set<Car> cars) {
        this.cars = cars;
    }

    @Embedded
    public Address getAddress() {
        return address;
    }

    public void setAddress(Address address) {
        this.address = address;
    }

    @Column(name = "name", nullable = false)
    public String getName() {
        return name;
    }

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

}

===================================================================

The following code saves a 'Sale' instance to the mysql database. Eventually a car_sale record, two cars records and two sales_car_join records will be saved in the database.
===================================================================

package com.shyarmal;

import java.util.HashSet;
import java.util.Set;

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

import com.shyarmal.hibernate.Address;
import com.shyarmal.hibernate.Car;
import com.shyarmal.hibernate.HibernateUtil;
import com.shyarmal.hibernate.Sale;

public class Main {

    public static void main(String[] args) {
        Session session = HibernateUtil.getSessionFactory().getCurrentSession();
        Transaction transaction = session.beginTransaction();
        session.save(getSale());
        transaction.commit();
    }
   
    private static Sale getSale() {
        Sale sale = new Sale();
        sale.setAddress(new Address("7832", "Woxhall", "Union Place"));
        sale.setName("xyz");
        sale.setCars(getCarSet());
        return sale;
    }
   
    private static Set<Car> getCarSet() {
        Set<Car> carSet = new HashSet<Car>();
       
        Car car1 = new Car();
        car1.setBrand("Vitz");
        car1.setMake("Toyota ");
        car1.setModel("2009");
        car1.setCapacity(20.4);
        car1.setPrice(30000000);
        carSet.add(car1);
       
        Car car2 = new Car();
        car2.setBrand("Camry");
        car2.setMake("Toyota ");
        car2.setModel("2011");
        car2.setCapacity(20.4);
        car2.setPrice(45000000);
        carSet.add(car2);
       
        return carSet;
    }
}


thanks,
Shyarmal.

Hibernate Annotations Example

This is a simple demonstration of how hibernate annotations (actually JPA) can be used. I have used mysql database in this example. First let's create a maven project with the following command.

mvn archetype:generate --batch-mode -DarchetypeArtifactId=maven-archetype-quickstart -DgroupId=com.shyarmal.hibernate -DartifactId=hibernate-eg

Create a folder named 'resources' in ....../hibernate-eg/src/main. Then create a file with the name hibernate.cfg.xml in it and paste the following xml codes. The file, hibernate.cfg.xml needs to be in the class path for the application to run successfully.

===================================================================

<?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="connection.url">jdbc:mysql://localhost/test</property>
        <property name="connection.username">root</property>
        <property name="connection.password">123</property>
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
    
        <property name="show_sql">true</property>
    
        <property name="format_sql">true</property>
        <property name="hbm2ddl.auto">create</property>
    
        <property name="connection.pool_size">1</property>
        <property name="current_session_context_class">thread</property>

        <mapping class="com.shyarmal.hibernate.Car"/>
    </session-factory>
</hibernate-configuration>

===================================================================
     A hibernate session factory is configured in hibernate.cfg.xml. connection.url, connection.username and connection.password are your database url, username and password respectively. Since mysql is used the driver class should be 'com.mysql.jdbc.Driver' and the dialect should be 'org.hibernate.dialect.MySQLDialect'.
     The property show_sql is set to true, which means the sql queries executed by hibernate will be shown in the log. Each time the session factory is created, the database schema will be created as the property, hbm2ddl.auto is set as 'create'.
     Further the database connection pool size is 1 and hibernate's automatic session context management is used. However hibernate's default connection pool is not encouraged to be used for production.
     Mapping classes have to be given in the configuration file. In this example only one class is used which is 'com.shyarmal.hibernate.Car'. 

     The class below instantiates a session factory with the above configurations. HibernateUtil is singleton.
===================================================================

package com.shyarmal.hibernate;

import org.hibernate.SessionFactory;
import org.hibernate.cfg.AnnotationConfiguration;

public class HibernateUtil {

    private static SessionFactory sessionFactory = buildSessionFactory();
   
    private static SessionFactory buildSessionFactory() {
        return new AnnotationConfiguration().configure().buildSessionFactory();
    }
   
    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }
}

===================================================================

The class 'Car' is the class which will be modelled to the database. An instance of this class is mapped to one record of database table which models the class.
===================================================================

package com.shyarmal.hibernate;

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

@Entity
@Table(name="cars")
public class Car {

    private Long id;
    private String make;
    private String brand;
    private String model;
    private double capacity;
    private double price;

    @Id
    @GeneratedValue
    public Long getId() {
        return id;
    }

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

    public String getMake() {
        return make;
    }

    public void setMake(String make) {
        this.make = make;
    }

    public String getBrand() {
        return brand;
    }

    public void setBrand(String brand) {
        this.brand = brand;
    }

    public String getModel() {
        return model;
    }

    public void setModel(String model) {
        this.model = model;
    }

    public double getCapacity() {
        return capacity;
    }

    public void setCapacity(double capacity) {
        this.capacity = capacity;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

}

===================================================================

Annotations used;
  • @Entity: The class denoted by this will be considered as an entity (which is mapped to a database table)
  • @Table: The properties of the table to be created such as the name can be given here.
  • @Id: The attribute denoted by this will be taken to be the primary key of the record saved in the table.
  • @GeneratedValue: This makes hibernate generate a value for the annotated attribute.
n.b. If the @Table annotation was not present, The name of the table created will be the same as the name of the class. Column names can be explicitly mentioned with @Column attribute. Since it is not done here, the field names of the table will be the same as the field names of the class.

===================================================================
package com.shyarmal;

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

import com.shyarmal.hibernate.Car;
import com.shyarmal.hibernate.HibernateUtil;

public class Main {

    public static void main(String[] args) {
        Session session = HibernateUtil.getSessionFactory().getCurrentSession();
        Transaction transaction = session.beginTransaction();
        Car car = new Car();
        car.setBrand("Vitz");
        car.setMake("Toyota ");
        car.setModel("2009");
        car.setCapacity(20.4);
        car.setPrice(30000000);
        session.save(car);
        transaction.commit();
    }
}

===================================================================
The main method above creates a hibernate session from the session factory. A transaction is started for the operation. An instance of 'Car' is saved to the session and subsequently committed to the database.

The 'Main' class can be run with the following maven command.
mvn clean compile exec:java -Dexec.mainClass=com.shyarmal.Main

The pom.xml file used is below.
===================================================================

<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/maven-v4_0_0.xsd">
 
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.shyarmal.hibernate</groupId>
  <artifactId>hibernate-eg</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>hibernate-eg</name>
  <url>http://maven.apache.org</url>
 
  <dependencies>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-annotations</artifactId>
        <version>3.5.6-Final</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate</artifactId>
        <version>3.6.0.Beta2</version>
        <type>pom</type>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.17</version>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-api</artifactId>
        <version>1.6.2</version>
    </dependency>
    <dependency>
        <groupId>org.javassist</groupId>
        <artifactId>javassist</artifactId>
        <version>3.15.0-GA</version>
    </dependency>
  </dependencies>
 
</project>

thanks,
Shyarmal.