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Example of @FetchProfile in Hibernate Annotation

By Arvind Rai, February 06, 2013
@FetchProfile is the alternative of @Fetch annotation. @FetchProfile do the same thing as @Fetch do. EAGER fetching or LAZY fetching can be set by @FetchProfile in Hibernate Annotation. The advantage of @FetchProfile is that it can be set at package level too. To make an entity for EAGER fetching, we need to annotate entity with @FetchProfile. A fetch profile needs to be given. At the time of fetching this entity, we need to enable fetch profile by enableFetchProfile. After enabling fetch profile, EAGER fetching will be available till the session. If we want to stop EAGER fetching we need to call the method disableFetchProfile.
Country.java
package com.concretepage.persistence;
import java.io.Serializable;
import java.util.Set;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToMany;
import org.hibernate.annotations.FetchMode;
import org.hibernate.annotations.FetchProfile;
@Entity
@FetchProfile(name = "country_states", fetchOverrides = {
		   @FetchProfile.FetchOverride(entity = Country.class, association = "states", mode = FetchMode.JOIN)
})
public class Country implements Serializable {
	private static final long serialVersionUID = 1L;
	@Id
	@Column(name="id")
	private int id;
	
	@Column(name="name")
	private String name;
	
	@OneToMany(cascade=CascadeType.ALL)
	@JoinColumn(name="countryId")
	private Set<State> states;
	
	public Country(int id,String name,Set<State> states){
		this.id=id;
		this.name=name;
		this.states=states;
	}
	public Country(){
	}
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public Set<State> getStates() {
		return states;
	}
	public void setStates(Set<State> states) {
		this.states = states;
	}
}
 



State.java
package com.concretepage.persistence;

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

@Entity
@Table(name = "state")
public class State {
	@Id
	@Column(name = "id")
	private int id;

	@Column(name = "name")
	private String name;
	
	@Column(name="cid")
	private int countryId;
	public State(int id,int countryId,String name){
		this.id=id;
		this.name=name;
	}
	public State(){}
	public String getName() {
		return name;
	}

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

	public int getId() {
		return id;
	}

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

	public int getCountryId() {
		return countryId;
	}

	public void setCountryId(int countryId) {
		this.countryId = countryId;
	}
}
 
hibernate.cfg.xml
<!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.url">
    jdbc:mysql://localhost:3306/hibernate</property>
    <property name="hibernate.connection.username">root</property>
    <property name="hibernate.connection.password"></property>
    <property name="hibernate.connection.pool_size">10</property>
    <property name="show_sql">true</property>
    <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
    <property name="hibernate.hbm2ddl.auto">update</property>
    <property name="hibernate.cache.use_second_level_cache">true</property>
    <mapping class="com.concretepage.persistence.State"/>
    <mapping class="com.concretepage.persistence.Country"/>
   </session-factory>
</hibernate-configuration>
 
HibernateUtil.java
package com.concretepage.util;
import java.util.HashSet;
import java.util.Set;

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

import com.concretepage.persistence.Country;
import com.concretepage.persistence.State;

public class HibernateUtil {
	private static final SessionFactory concreteSessionFactory;
	    static {
	        try {
	            concreteSessionFactory = new AnnotationConfiguration()
	                    .configure().buildSessionFactory();
	        } catch (Throwable ex) {
	            throw new ExceptionInInitializerError(ex);
	        }
	    }
	    public static Session getSession()
	            throws HibernateException {
	        return concreteSessionFactory.openSession();
	    }
	    
	    public static void main(String... args){
	    	Session session=getSession();
	    	session.beginTransaction();
	    	State s1= new State(1,1,"UP");
	    	State s2= new State(2,1,"MP");
	    	Set<State> states= new HashSet<State>();
	    	states.add(s1);
	    	states.add(s2);
	    	Country country= new Country(1,"India",states);
	    	session.persist(country);
	    	session.getTransaction().commit();
	    	session.close();
	    	//start new session to check fetch type
	        session=getSession();
	    	session.beginTransaction();
	    	//enable fetch profile for EAGER fetching
	    	session.enableFetchProfile("country_states");
	    	Country con= (Country)session.get(Country.class,new Integer(1));
	    	System.out.println(con.getStates().size());
	    	//disable fetch profile
	    	session.disableFetchProfile("country_states");
	        session.clear();
	    }
	}
 
Output
Hibernate: insert into Country (name, id) values (?, ?)
Hibernate: insert into state (cid, name, id) values (?, ?, ?)
Hibernate: insert into state (cid, name, id) values (?, ?, ?)
Hibernate: update state set countryId=? where id=?
Hibernate: update state set countryId=? where id=?
Hibernate: select country0_.id as id1_0_, country0_.name as name1_0_ from Country country0_ where country0_.id=?
Hibernate: select states0_.countryId as countryId1_1_, states0_.id as id1_, states0_.id as id0_0_, states0_.cid as cid0_0_, states0_.name as name0_0_ from state states0_ where states0_.countryId=? 
2
 
In the select query we can see that both the table country and state is being fetched.
POSTED BY
ARVIND RAI
ARVIND RAI
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