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The Criteria interface allows to create
and execute object-oriented queries. It is powerful alternative to the
HQL but has own limitations. Criteria Query is used mostly in case of multi
criteria search screens, where HQL is not very effective.
The interface org.hibernate.Criteria is
used to create the criterion for the search. The org.hibernate.Criteria
interface represents a query against a persistent class. The Session is a
factory for Criteria instances. Here is a simple example of Hibernate Criterial
Query:
import org.hibernate.Session;
import org.hibernate.*;
import org.hibernate.cfg.*;
import java.util.*;
public class HibernateCriteriaQueryExample {
public static void main(String[] args) {
Session session = null;
try {
// This step will read
hibernate.cfg.xml and prepare hibernate for
// use
SessionFactory
sessionFactory = new Configuration().configure()
.buildSessionFactory();
session =
sessionFactory.openSession();
//Criteria Query Example
Criteria crit =
session.createCriteria(Insurance.class);
List insurances =
crit.list();
for(Iterator it =
insurances.iterator();it.hasNext();){
Insurance insurance =
(Insurance) it.next();
System.out.println("
ID: " + insurance.getLngInsuranceId());
System.out.println("
Name: " + insurance.getInsuranceName());
}
session.close();
} catch (Exception e) {
System.out.println(e.getMessage());
} finally {
}
}
}
The above Criteria Query example selects
all the records from the table and displays on the console. In the above code
the following code creates a new Criteria instance, for the class Insurance:
Criteria crit =
session.createCriteria(Insurance.class);
The code:
List insurances = crit.list();
creates the sql query and execute against
database to retrieve the data.
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