Hibernate Criteria Query Simple Example

Hibernate Criteria API offers to create dynamic queries without using HQL. Here is one simple example to retrieve Student object using Hibernate Criteria.

Software Used

Java 1.7

Hibernate 3

MySql 5

Eclipse Juno

1. Create a Java project

Create a Java project and update Hibernate jars and Mysql driver jar in to build path. (Download Hibernate , MySql Driver)

2. Create a Student Entity

package com.pretech;
 
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
 
@Entity
@Table(name = "student", catalog = "hibernateschema")
public class Student  {
    @Id
    @Column(name = "name", unique = true, nullable = false, length = 100)
    private String name;
 
    @Column(name = "standard", unique = true, nullable = false, length = 200)
    private String standard;
   
 
    public String getStandard() {
        return standard;
    }
 
    public void setStandard(String standard) {
        this.standard = standard;
    }
 
    public String getName() {
        return name;
    }
 
    public void setName(String string) {
        name = string;
    }
 
    public String toString() {
        return name;
    }
}

3. Create Hibernate config file (hibernate.cfg.xml)

<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD//EN"
    "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory name="studentFactory">
            <property name="connection.driver_class">
                 com.mysql.jdbc.Driver
            </property>
        <property name="connection.url">
             jdbc:mysql://localhost:3306/hibernateschema
        </property>
        <property name="connection.username">
             root
        </property>
        <property name="connection.password">
            root
        </property>
            <property name="connection.pool_size">5</property>
            <!-- SQL dialect -->
            <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
            <!-- Echo all executed SQL to stdout -->
            <property name="show_sql">true</property>
             <property name="hbm2ddl.auto">update</property>
             <mapping class="com.pretech.Student"></mapping>
    </session-factory>
</hibernate-configuration>

4.Create a Main program

In this program first we are inserting a student record and retrieving using Hibernate Criteria

package com.pretech;
 
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
 
import org.hibernate.Criteria;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.Restrictions;
 
public class CriteriaQueryExample {
    private static SessionFactory sessionFactory;
    public static void main(String[] args) {
        try {
            sessionFactory = new Configuration().configure("hibernate.cfg.xml")
                    .buildSessionFactory();
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
        Session session = sessionFactory.openSession();
       
       
        //Inserting Student Records
        Transaction tx = session.beginTransaction();
        Student student = new Student();
        student.setName("Raj");
        student.setStandard("10th Standard");
        session.save(student);
        tx.commit();
        System.out.println("Record save successfully");
       
        //Fetching Student object
        Criteria crit = session.createCriteria(Student.class);
        Criterion cn = Restrictions.eq("name","Raj");
        crit.add(cn);
        List l=crit.list();
        Iterator it=l.iterator();
         while(it.hasNext())
        {
             Student stud=(Student)it.next();
            System.out.println(stud.getName());
            System.out.println(stud.getStandard());
            System.out.println("-----------------");
        }
        session.close();
        sessionFactory.close();
    }
 
}

5.Output

Run the main program and see below output

Hibernate: insert into hibernateschema.student (standard, name) values (?, ?)
Record save successfully
Hibernate: select this_.name as name0_0_, this_.standard as standard0_0_ from hibernateschema.student this_ where this_.name=?
Raj
10th Standard
-----------------