HibernatePlugIn for Struts

To configure Hibernate in a Jakarta-Struts application:

1. Create your struts-config.xml file.

2. Add the following configuration for the plugin:

<plug-in className="edu.arbor.util.plugin.HibernatePlugIn">

? <!-- 'path-to-config-file' is relative to the root of the class

?????? path.? It MUST start with a '/'. The default is

?????? "/hibernate.cfg.xml" -->

? <set-property property="configFilePath" value="path-to-config-file" />

? <set-property property="storeInServletContext" value="true-or-false" />

</plug-in>

?

3. Copy the code into a source file and compile.

package edu.arbor.util.plugin;

?

import java.net.URL;

import javax.servlet.ServletContext;

import javax.servlet.ServletException;

import net.sf.hibernate.SessionFactory;

import net.sf.hibernate.cfg.Configuration;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import org.apache.struts.action.ActionServlet;

import org.apache.struts.action.PlugIn;

import org.apache.struts.config.ModuleConfig;

?

/**

?* Implements the <code>PlugIn</code> interface to configure the Hibernate

?* data persistence library.? A configured

?* <code>net.sf.hibernate.SessionFactory</code> is stored in the

?* <code>ServletContext</code> of the web application unless the property

?* <code>storedInServletContext</code> is set to <code>false</code>.

?*

?* <plugin class="net.sf.hibernate.plugins.struts.HibernatePlugIn">

?*?? <set-property name="configFilePath"

?*?????????????? ??value="path-to-config-file"/>

?*?? <set-property name="storedInServletContext&quot"

?*??????????????? value="true-or-false"/>

?* </plugin>

?*

?* @author? <a href="mailto:bhandy@users.sf.net">Bradley M. Handy</a>

?* @version 1.0

?*/

public class HibernatePlugIn implements PlugIn {

???

??? /**

???? * the key under which the <code>SessionFactory</code> instance is stored

???? * in the <code>ServletContext</code>.

???? */

??? public static final String SESSION_FACTORY_KEY

??????????? = SessionFactory.class.getName();

?

??? private static Log _log = LogFactory.getLog(HibernatePlugIn.class);

???

??? /**

???? * indicates whether the <code>SessionFactory</code> instance will be stored

???? * in the <code>ServletContext</code>, or not.

???? */

??? private boolean _storedInServletContext = true;

???

??? /**

???? * the path to the xml configuration file.? the path should start with a

???? * '/' character and be relative to the root of the class path.

???? * (DEFAULT:? "/hibernate.cfg.xml")

???? */

??? private String _configFilePath = "/hibernate.cfg.xml";

?

??? private ActionServlet _servlet = null;

??? private ModuleConfig _config = null;

??? private SessionFactory _factory = null;

?

??? /**

???? * Destroys the <code>SessionFactory</code> instance.

???? */

??? public void destroy() {

??????? _servlet = null;

??????? _config = null;

???????

??????? try {

??????????? _log.debug("Destroying SessionFactory...");

???????????

??????????? _factory.close();

???????????

??????????? _log.debug("SessionFactory destroyed...");

??????? } catch (Exception e) {

??????????? _log.error("Unable to destroy SessionFactory...(exception ignored)",

??????????????????? e);

??????? }

??? }

???

??? /**

???? * Initializes the <code>SessionFactory</code>.

???? * @param servlet the <code>ActionServlet</code> instance under which the

???? *??????? plugin will run.

???? * @param config the <code>ModuleConfig</code> for the module under which

???? *??????? the plugin will run.

???? */

??? public void init(ActionServlet servlet, ModuleConfig config)

??? throws ServletException {

??????? _servlet = servlet;

??????? _config = config;

???????

??????? initHibernate();

??? }

???

??? /**

???? * Initializes Hibernate with the config file found at

???? * <code>configFilePath</code>.

???? */

??? private void initHibernate() throws ServletException {

??????? Configuration configuration = null;

??????? URL configFileURL = null;

??????? ServletContext context = null;

???????

??????? try {

??????????? configFileURL = HibernatePlugIn.class.getResource(_configFilePath);

?

??????????? context = _servlet.getServletContext();

?

??????????? if (_log.isDebugEnabled()) {

??????????????? _log.debug("Initializing Hibernate from "

??????????????????????? + _configFilePath + "...");

??????????? }

???????????

??????????? configuration = (new Configuration()).configure(configFileURL);

??????????? _factory = configuration.buildSessionFactory();

???????????

??????????? if (_storedInServletContext) {

??????????????? _log.debug("Storing SessionFactory in ServletContext...");

??? ????????????

??????????????? context.setAttribute(SESSION_FACTORY_KEY, _factory);

??????????? }

??????????

??????? } catch (Throwable t) {

??????????? _log.error("Exception while initializing Hibernate.");

??????????? _log.error("Rethrowing exception...", t);

???????????

??????????? throw (new ServletException(t));

??????? }

??? }

???

??? /**

???? * Setter for property configFilePath.

???? * @param configFilePath New value of property configFilePath.

???? */

??? public void setConfigFilePath(String configFilePath) {

??????? if ((configFilePath == null) || (configFilePath.trim().length() == 0)) {

??????????? throw new IllegalArgumentException(

??????????????????? "configFilePath cannot be blank or null.");

??????? }

???????

??????? if (_log.isDebugEnabled()) {

??????????? _log.debug("Setting 'configFilePath' to '"

??????????????????? + configFilePath + "'...");

??????? }

???????

??????? _configFilePath = configFilePath;

??? }

???

??? /**

???? * Setter for property storedInServletContext.

???? * @param storedInServletContext New value of property storedInServletContext.

???? */

??? public void setStoredInServletContext(String storedInServletContext) {

??????? if ((storedInServletContext == null)

??????????????? || (storedInServletContext.trim().length() == 0)) {

??????????? storedInServletContext = "false";

??????? }

???????

??????? if (_log.isDebugEnabled()) {

??????????? _log.debug("Setting 'storedInServletContext' to '"

??????????????????? + storedInServletContext + "'...");

??????? }

???????

??????? _storedInServletContext

??????????????? = new Boolean(storedInServletContext).booleanValue();

??? }

???

}

?

?

A Usage example would be excellent!	08 Sep 2003, 16:07	themax
A usage example would be excellent!
?
Some more meat in the bones. Configruing hibernate with struts	26 Nov 2003, 14:12	mark.lowe
<?xml version='1.0' encoding='utf-8'?> <!DOCTYPE hibernate-configuration PUBLIC ??????? "-//Hibernate/Hibernate Configuration DTD 2.0//EN" ????????????? "http://hibernate.sourceforge.net/hibernate-configuration -2.0.dtd"> ? <hibernate-configuration> ? ??? <!-- a SessionFactory instance listed as /jndi/name --> ?? <session-factory name="foo:/hibernate/SessionFactory"> ??????? <!-- properties --> ??????? <property name="dialect">net.sf.hibernate.dialect.MySQLDialect</property> ??????? <property name="connection.username">brian</property> ??????? <property name="connection.password">arses</property> ??????? <property name="connection.url">jdbc:mysql://localhost:3306/ mydata</property> ??????? <property name="connection.driver_class">com.mysql.jdbc.Driver</property> ??????? <property name="show_sql">true</property> ??????? <property name="use_outer_join">true</property> ??????? <property name="transaction.factory_class">net.sf.hibernate.transaction.JDBCTra nsactionFactory</property> ??????? <property name="dbcp.minIdle">1</property> ??????? <property name="cache.use_query_cache">true</property> ????????????? ??????? <!-- mapping files --> ??????? <mapping resource="com/sparrow/om/Arse.hbm.xml"/> ? ??? </session-factory> ? </hibernate-configuration> ? ? and in struts config.. ? ?????? <plug-in className="edu.arbor.util.plugin.HibernatePlugIn"> ????????????? <set-property property="storedInServletContext" value="true"/> ?????? </plug-in> ? .. in struts action .. Context ctx = new InitialContext(); SessionFactory sf = (SessionFactory) ctx.lookup("foo:/hibernate/ SessionFactory"); hibSession = sf.openSession(); ? Query query = hibSession.createQuery("from com.sparrow.om.Arse"); Iterator it = query.iterate(); ???????????????????? while(it.hasNext()) { ????????????? Arse arse = (Arse) it.next(); ????????????? arseList.add(arse); } ???????????????????? request.setAttribute("arses", arseList.toArray()); ? ..
?
Tomcat notes	23 Aug 2004, 18:03	chrismaeda
The previous example (where the SessionFactory is bound in the JNDI tree) doesn't work for Tomcat since Tomcat's JNDI is read-only. ? If you store the SessionFactory in the servlet context, you get it back with the following code: ? ?? (SessionFactory) servletContext.getAttribute (HibernatePlugIn.SESSION_FACTORY_KEY); ? If you are using JSP 1.2 or 2.0, you could also use this EL expression: ? ?? "${applicationScope['net.sf.hibernate.SessionFactory']}" ? This works for generic servlets as well.? Just execute the plugin code in the servlet's init() method.

?

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