Configure hibernate with struts

A tutorial to show how to integrate Hibernate with in a web application developed with Apache Struts 1.x.

Steps of the integration :

1. Create a new Hibernate Struts plug-in file to set the Hibernate session factory in servlet context, and include this file in struts-config.xml file.
2. In Struts, get the Hibernate session factory from servlet context, and do whatever Hibernate task you want

1. Hibernate Struts Plug-in

Create a Hibernate Struts Plug-in, get the Hibernate session factory, store it into the servlet context for later user –servlet.getServletContext().setAttribute(KEY_NAME, factory);.

package com.mkyong.common.plugin;

import java.net.URL;
import javax.servlet.ServletException;

import org.apache.struts.action.ActionServlet;
import org.apache.struts.action.PlugIn;
import org.apache.struts.config.ModuleConfig;
import org.hibernate.HibernateException;
import org.hibernate.MappingException;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class HibernatePlugin implements PlugIn {
   private Configuration config;
   private SessionFactory factory;
   private String path = "/hibernate.cfg.xml";
   private static Class clazz = HibernatePlugin.class;

   public static final String KEY_NAME = clazz.getName();

   public void setPath(String path) {
      this.path = path;
   }

   public void init(ActionServlet servlet, ModuleConfig modConfig)
      throws ServletException {

      try {

      //save the Hibernate session factory into serlvet context
         URL url = HibernatePlugin.class.getResource(path);
         config = new Configuration().configure(url);
         factory = config.buildSessionFactory();
         servlet.getServletContext().setAttribute(KEY_NAME, factory);

      } catch (MappingException e) {
         throw new ServletException();
      } catch (HibernateException e) {
         throw new ServletException();
      }

   }

   public void destroy() {
      try {
         factory.close();
      } catch (HibernateException e) {
         e.printStackTrace();
      }
   }
}

2. struts-config.xml

Include the Hibernate Struts plug-in into the Struts configuration file (struts-config.xml).

<struts-config>
    ...
    <plug-in className="com.mkyong.common.plugin.HibernatePlugin">
       <set-property property="path" value="/hibernate.cfg.xml"/>
    </plug-in>
 ...
<struts-config>

3. Get the Hibernate session factory

In Struts action class, you can get the Hibernate session factory from servlet context.

servlet.getServletContext().getAttribute(HibernatePlugin.KEY_NAME);

and do whatever Hibernate task as normal.

package com.mkyong.customer.action;

import java.util.Date;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.beanutils.BeanUtils;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.hibernate.Session;
import org.hibernate.SessionFactory;

import com.mkyong.common.plugin.HibernatePlugin;
import com.mkyong.customer.form.CustomerForm;
import com.mkyong.customer.model.Customer;

public class AddCustomerAction extends Action{

  public ActionForward execute(ActionMapping mapping,ActionForm form,
 HttpServletRequest request,HttpServletResponse response)
  throws Exception {

        SessionFactory sessionFactory =
          (SessionFactory) servlet.getServletContext()
                            .getAttribute(HibernatePlugin.KEY_NAME);

 Session session = sessionFactory.openSession();

 CustomerForm customerForm = (CustomerForm)form;
 Customer customer = new Customer();

 //copy customerform to model
 BeanUtils.copyProperties(customer, customerForm);

 //save it
 customer.setCreatedDate(new Date());

 session.beginTransaction();
 session.save(customer);
 session.getTransaction().commit();

 return mapping.findForward("success");

  }
}