Generic Dao: Find : DAO Generic DAO « Hibernate « Java





Generic Dao: Find

/////////////////////////////////////////////////////////////////////////
import java.util.*;

import java.sql.*;
import org.hibernate.*;
import org.hibernate.criterion.*;

public class Main {
  
  public static void main(String[] args) {
    HibernateUtil.setup("create table EVENTS ( uid int, name VARCHAR, start_Date date, duration int);");
    
    // hibernate code start

        EventDao eventDao = new EventDao();
        Event event = new Event();
        event.setName("Create");

        eventDao.create(event);

        Event event2 = (Event) eventDao.find(event.getId());
        System.out.println("Loaded Name:"+event2.getName());

        
        HibernateUtil.checkData("select uid, name from events");        

        
    // hibernate code end
  }
  
}



/////////////////////////////////////////////////////////////////////////
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.Transaction;

import java.util.List;


public class EventDao extends AbstractDao {
    public EventDao() {
        super();
    }

    /**
     * Insert a new Event into the database.
     * @param event
     */
    public void create(Event event) throws DataAccessLayerException {
        super.saveOrUpdate(event);
    }


    /**
     * Delete a detached Event from the database.
     * @param event
     */
    public void delete(Event event) throws DataAccessLayerException {
        super.delete(event);
    }

    /**
     * Find an Event by its primary key.
     * @param id
     * @return
     */
    public Event find(Long id) throws DataAccessLayerException {
        return (Event) super.find(Event.class, id);
    }

    /**
     * Updates the state of a detached Event.
     *
     * @param event
     */
    public void update(Event event) throws DataAccessLayerException {
        super.saveOrUpdate(event);
    }

    /**
     * Finds all Events in the database.
     * @return
     */
    public List findAll() throws DataAccessLayerException{
        return super.findAll(Event.class);
    }

}




/////////////////////////////////////////////////////////////////////////

import java.io.Serializable;
import java.util.Date;
import java.util.Set;
import java.util.LinkedHashSet;

public class Event implements Serializable {
    private Long id;
    private int duration;
    private String name;
    private Date startDate;

    public Event() {

    }

    public Event(String name) {
        this.name = name;
    }

    /**
     * @hibernate.id generator-class="native" column="uid"
     * @return
     */
    public Long getId() { return id; }
    public void setId(Long id) { this.id = id; }

    /**
     * @hibernate.property column="name"
     * @return
     */
    public String getName() { return name; }
    public void setName(String name) { this.name = name;   }

    /**
     * @hibernate.property column="start_date"
     * @return
     */
    public Date getStartDate() { return startDate; }
    public void setStartDate(Date startDate) { this.startDate = startDate; }

    /**
     * @hibernate.property column="duration"
     * @return
     */
    public int getDuration() { return duration; }
    public void setDuration(int duration) { this.duration = duration; }

}



/////////////////////////////////////////////////////////////////////////

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping >
    <class name="Event" table="events">
        <id name="id" column="uid" type="long">
            <generator class="increment"/>
        </id>
        <property name="name" type="string"/>
        <property name="startDate" column="start_date" type="date"/>
        <property name="duration" type="integer"/>
    </class>
</hibernate-mapping>




/////////////////////////////////////////////////////////////////////////

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.Query;

import java.util.List;

public abstract class AbstractDao {
    private Session session;
    private Transaction tx;

    public AbstractDao() {
        HibernateFactory.buildIfNeeded();
    }

    protected void saveOrUpdate(Object obj) {
        try {
            startOperation();
            session.saveOrUpdate(obj);
            tx.commit();
        } catch (HibernateException e) {
            handleException(e);
        } finally {
            HibernateFactory.close(session);
        }
    }

    protected void delete(Object obj) {
        try {
            startOperation();
            session.delete(obj);
            tx.commit();
        } catch (HibernateException e) {
            handleException(e);
        } finally {
            HibernateFactory.close(session);
        }
    }

    protected Object find(Class clazz, Long id) {
        Object obj = null;
        try {
            startOperation();
            obj = session.load(clazz, id);
            tx.commit();
        } catch (HibernateException e) {
            handleException(e);
        } finally {
//            HibernateFactory.close(session);
        }
        return obj;
    }

    protected List findAll(Class clazz) {
        List objects = null;
        try {
            startOperation();
            Query query = session.createQuery("from " + clazz.getName());
            objects = query.list();
            tx.commit();
        } catch (HibernateException e) {
            handleException(e);
        } finally {
            HibernateFactory.close(session);
        }
        return objects;
    }

    protected void handleException(HibernateException e) throws DataAccessLayerException {
        HibernateFactory.rollback(tx);
        throw new DataAccessLayerException(e);
    }

    protected void startOperation() throws HibernateException {
        session = HibernateFactory.openSession();
        tx = session.beginTransaction();
    }
}



/////////////////////////////////////////////////////////////////////////

<?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>

        <!-- Database connection settings -->
        <property name="connection.driver_class">org.hsqldb.jdbcDriver</property>
        <property name="connection.url">jdbc:hsqldb:data/tutorial</property>
        <property name="connection.username">sa</property>
        <property name="connection.password"></property>

        <!-- JDBC connection pool (use the built-in) -->
        <property name="connection.pool_size">1</property>

        <!-- SQL dialect -->
        <property name="dialect">org.hibernate.dialect.HSQLDialect</property>

        <!-- Echo all executed SQL to stdout -->
        <property name="show_sql">true</property>

        <mapping resource="Event.hbm.xml"/>
    </session-factory>

</hibernate-configuration>
           
       










HibernateGenericDaoFind.zip( 4,583 k)

Related examples in the same category

1.Generic Dao: Create
2.Generic: Dao Delete
3.Generic Dao Find All
4.Generic Dao Save Or Update
5.Generic Dao: Update