Or, use Tapernate! Other folks are using it and they seem to like it a lot. It does roughly the same thing as the Spring OpenSessionInViewFilter, but it also does a whole lot more. Check out the documentation at:
www.carmanconsulting.com/tapernate James -----Original Message----- From: albartell [mailto:[EMAIL PROTECTED] Sent: Thursday, June 08, 2006 12:37 PM To: 'Tapestry users' Subject: Tapestry+Spring+Hibernate was ->RE: @For within a @contrib:Table Ok, I have looked into the Tapestry+Spring+Hibernate approach prescribed by Eric and have some questions. I am going to go into some code depth for the archives. Note that I have visited http://wiki.apache.org/tapestry/FrequentlyAskedQuestions/SpringHibernate and some other threads in this list but think that I still need some final clarification from someone who has lived it and can state that my following scenario will be addressed by the introduction of Spring into the mix. Currently I use myeclipseide.com to generate my DAO POJO's from MySQL tables. In the relationship of a Lead (parent) to Leadtag (child) it creates the following class (note the absence of any Hibernate related code)... public abstract class AbstractLead implements java.io.Serializable { private Set leadtags = new HashSet(0); ...code ommitted for brevity sake... public Set getLeadtags() { return this.leadtags; } public void setLeadtags(Set leadtags) { this.leadtags = leadtags; } } The above is "fronted" by the Lead.hbm.xml file which is as follows: <hibernate-mapping> <class name="com.rxs.dao.Lead" table="lead" catalog="rxsweb"> <id name="leaduid" type="java.lang.Integer"> <column name="leaduid" /> <generator class="native" /> </id> ...code ommitted for brevity sake... <set name="leadtags" inverse="true"> <key> <column name="leaduid" not-null="true" /> </key> <one-to-many class="com.rxs.dao.Leadtag" /> </set> </class> </hibernate-mapping> My hibernate.cfg.xml file is configured as follows: <hibernate-configuration> <session-factory> <property name="connection.datasource">java:comp/env/jdbc/rxscp</property> <property name="dialect">org.hibernate.dialect.MySQLDialect</property> <property name="hibernate.show_sql">true</property> <mapping resource="com/rxs/dao/Lead.hbm.xml" /> <mapping resource="com/rxs/dao/Leadtag.hbm.xml"></mapping> </session-factory> </hibernate-configuration> I configure the DBCP (specified above) in the /META-INF/context.xml file as follows: <Context path="/rxs" docBase="/rxs" debug="0" reloadable="false"> <Resource name="jdbc/rxscp" auth="Container" type="javax.sql.DataSource" factory="org.apache.tomcat.dbcp.dbcp.BasicDataSourceFactory" maxActive="100" maxIdle="30" minIdle="10" maxWait="15000" username="myuser" password="mypassword" driverClassName="com.mysql.jdbc.Driver" url="jdbc:mysql://localhost:3306/mydb" removeAbandoned="true" removeAbandonedTimeout="300" validationQuery="select 1" logAbandoned="true" testOnBorrow="true" testOnReturn="true" testWhileIdle="true" /> </Context> Here is where my problem comes. I traditionally have used a Servlet filter to initiate a single session per request as per the below DBConn.java code. When I need to make a call to the database I simply do a DBConn.sess().createQuery(...etc. The DBConn.sess() approach works great for when I want to manually do a specific query that isn't facilitated by the getters built by myeclipseide.com; but when I want to make use of getLeadtags() to produce a list it is not using DBConn.sess() but is instead invoking a new DB connection somehow someway (I have no idea how it does it, I just like the work I DON'T have to do:-) So I guess my question is this: Given the two methods of DB access I am doing (i.e. manual way using DBConn.sess(), and Hibernates zero code approach) will OpenSessionInViewFilter be able to appropriately intercept both and my lazy loading woes will be resolved? public class DBConn implements Filter { private static Logger logger = Logger.getLogger(DBConn.class.getName()) private static SessionFactory sessionFactory; private static ThreadLocal tl = new ThreadLocal(); static { try { sessionFactory = new Configuration().configure().buildSessionFactory(); } catch (HibernateException e) { System.err.println("Initial SessionFactory creation failed." + e); e.printStackTrace(); throw new ExceptionInInitializerError(e); } } public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { try { chain.doFilter(request, response); } finally { Session s = (Session) tl.get(); if (s != null) { try { s.flush(); s.close(); } catch (HibernateException e) { e.printStackTrace(); } tl.set(null); } } } public static Session sess() { Session s = (Session) tl.get(); if (s == null || !s.isOpen()) { try { s = sessionFactory.openSession(); } catch (HibernateException e) { e.printStackTrace(); } tl.set(s); } return s; } public void init(FilterConfig filterConfig) throws ServletException { } public void destroy() { } } Aaron Bartell http://mowyourlawn.com/blog -----Original Message----- From: Eric Fesler [mailto:[EMAIL PROTECTED] Sent: Thursday, June 08, 2006 8:26 AM To: Tapestry users Subject: Re: @For within a @contrib:Table Hi, I already had this issue in the past. It was due to the fact that the leadtagtype (or equivalent) method was called on the leadtag bean after the hibernate session was closed. There are two ways to solve the issue. 1°) Do not use lazy loading for the leadtagtype association 2°) Use the OpenSessionInViewFilter of the Spring framework. This filter opens the session only once per request and close it at the end of the request. --ERic --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
