Rich, Ya the binding thing with JNDI and tomcat is messed up.. for some reason I've read its Read Only.. but the strange thing is I WAS able to get it working when I bound to that resource from a static class, but as soon as I used a filter or a struts plugin it no longer worked.. really lame.
Regarding what happens after you load something from Hibernate. I'm still learning this myself, but I assume if you don't load ANYTHING lazily then you should be able to do anything with that variable and have no worries. However if you have an object that contains say a set of other objects, ie a team with a set of players, and set it to lazy loading, meaning when you load team 1, the players arent loaded until you call, getPlayers(), then at that point hibernate is still bound to your variable and will load that from the db assuming the session you initially loaded the team with is still open. Make sense? The way it works is hibernate has its own classes inherited from set/list/map etc that handle that.. and it uses those when you load sets. -David ----- Original Message ----- From: "Rich Garabedian" <[EMAIL PROTECTED]> To: "'David Erickson'" <[EMAIL PROTECTED]> Sent: Friday, December 19, 2003 11:12 AM Subject: RE: struts, hibernate, datasources .... so lost > David, > > David, thanks so much for your note. > > I guess I'll try having Hibernate setup the datasource if I can't get it > to work they way I'm trying now. Doing that really bothers me though. I > thought datasources were supposed to allow us to configure a single > point of entry and then just use the logical name everywhere ... and not > to have to worry about anything else. Need to change your database? Just > look in one location and change - easy as pie. Yeah, right. Configuring > a JDBC realm for authentication, and then a datasource in an entirely > different file just seems plain backwards to me. Grrrh. > > Sorry, I'm really frustrated right now. I spent hours trying to > determine why my web app was crashing on load. Come to find out, > ehcache.jar is required (at least it seems to be for me). Even though > the hibernate lib/readme says it's optional. (I can't find anywhere > where I specify cache useage). > > > The explanation below helps clear things up, but there still is one > thing I really don't understand. If, in my action, I use hibernate to > grab something from the data layer and store it in a local variable ... > don't I know hold that data in my hands. If the session closes now, then > who cares? I've already copied it into a local variable and can do what > I please with it. Right? > > Dunno, I'm sure that last question readily shows my ignorance of how the > entire processes works :-) > > > -----Original Message----- > > From: David Erickson [mailto:[EMAIL PROTECTED] > > Sent: Friday, December 19, 2003 1:00 PM > > To: Struts Users Mailing List; [EMAIL PROTECTED] > > Subject: Re: struts, hibernate, datasources .... so lost > > > > Rich I know how you feel. I just dealt with nearly the same problems > the > > other day. I for the life of me could not get Hibernate to bind to my > > JNDI > > datasource.. so I bailed on that and in my hibernate.cfg.xml I just > had it > > setup the datasource and manage it from there: > > > > <hibernate-configuration> > > > > <session-factory name="salesweb:/hibernate/SessionFactory"> > > > > <property > name="dialect">net.sf.hibernate.dialect.MySQLDialect</property> > > > > <property name="show_sql">true</property> > > > > <property name="connection.username">user</property> > > > > <property name="connection.password">pass</property> > > > > <property > > > name="connection.url">jdbc:mysql://192.168.0.104:3306/salesweb</property > > > > > > <property > name="connection.driver_class">com.mysql.jdbc.Driver</property> > > > > <property name="use_outer_join">true</property> > > > > <property > > > name="transaction.factory_class">net.sf.hibernate.transaction.JDBCTransa > ct > > io > > nFactory</property> > > > > <property name="dbcp.minIdle">1</property> > > > > </session-factory> > > > > </hibernate-configuration> > > > > etc. So what hibernate does when you build its config is load up a > JNDI > > name and bind its session to that at > salesweb:/hibernate/SessionFactory. > > Then I am using the hibernateFilter which the first run through will > build > > that config and also store a static instance of the factory within > that > > class. The reason its important to use the filter (to my > understanding) > > is > > this: > > > > User requests a webpage, goes to struts action, action calls > getSession() > > from the hibernatefilter, it binds that session to the current > executing > > thread and ships it to the action. Action loads the requested items, > > perhaps the item has a collection that is loaded lazily, so it doesnt > > actually get loaded in the action. Action finishes and forwards to > view > > (Note this is in the same thread!!), the view is a jsp that wants to > > render > > that lazily loaded collection. Well if you closed the session in your > > action this would fail. but because the session is still maintained > until > > the request is fully finished it succeeds. Make sense? Anyway thats > my > > understanding, I could be flawed =) > > > > Good luck! > > -David > > > > ----- Original Message ----- > > From: "Rich Garabedian" <[EMAIL PROTECTED]> > > To: <[EMAIL PROTECTED]> > > Sent: Friday, December 19, 2003 7:35 AM > > Subject: struts, hibernate, datasources .... so lost > > > > > > > After spending days on the net and the mailing lists I find > something is > > > just not getting through to me. I feel that what I'm doing is > > > conceptually simple; yet I can't seem to actually implement any of > it. I > > > think I have a rudimentary understanding of how to integrate > Hibernate > > > into Struts, but I'm unsure on a few points. > > > > > > First the datasource. I'm trying to set up a default data source > that > > > all web applications can use. I use container based authentication > and I > > > want my realm to use it as well. Trolling these lists showed me a > > > solution that does work with my realm (XML fragments follow below). > But > > > when I try to use that same datasource with Hibernate, my web > > > application fails to load and I get the following error: > > > > > > SEVERE: Could not find datasource: java:comp/env/jdbc/prospectingDB > > > javax.naming.NameNotFoundException: Name jdbc is not bound in this > > > Context > > > > > > Here are the XML fragments from server.xml. > > > > > > First, I set up a global resource: > > > > > > <GlobalNamingResources> > > > > > > <Resource name = "jdbc/prospectingDB" > > > auth = "Container" > > > scope = "Shareable" > > > type = "javax.sql.DataSource"/> > > > > > > <ResourceParams name="jdbc/prospectingDB"> > > > > > > ... Usual parameters go here > > > > > > Right under the engine tag I define my realm. This works for my > > > container based auth > > > > > > <Engine name="Catalina" defaultHost="localhost" debug="10"> > > > > > > <Realm className = "org.apache.catalina.realm.DataSourceRealm" > > > debug = "99" > > > dataSourceName = "jdbc/prospectingDB" > > > userTable = "auth_roles_view" > > > userNameCol = "email" > > > userCredCol = "pwd" > > > userRoleTable = "auth_roles_view" > > > roleNameCol = "role"/> > > > > > > > > > Then I set up a resource link in the default context: > > > > > > <DefaultContext> > > > <ResourceLink name = "jdbc/prospectingDB" > > > global = "jdbc/prospectingDB" > > > type = "javax.sql.DataSource" /> > > > </DefaultContext> > > > > > > As I said, that all seems to work. But Hibernate bails: > > > > > > <hibernate-configuration> > > > <session-factory name="prospecting/hibernate/SessionFactory"> > > > <property > > > > name="connection.datasource">java:comp/env/jdbc/prospectingDB</property> > > > <property name="show_sql">false</property> > > > <property > > > name="dialect">net.sf.hibernate.dialect.PostgreSQLDialect</property> > > > <mapping resource="Employee.hbm.xml"/> > > > </session-factory> > > > </hibernate-configuration> > > > > > > I can't seem to figure out why. If I change the server.xml to define > the > > > datasource in my web-app context, then I get problems with container > > > based authentication not finding the datasource?? > > > > > > ... and speaking of Hibernate, I think I figured out how to use the > > > HibernatePlugIn. I use that to set-up a Hibernate session factory on > web > > > app instantiation. But what I'm not 100% sure on is why I need to > set-up > > > a filter to implement the open session in view pattern. One of the > > > examples I found on the hibernate site doesn't seem to use that > filter. > > > Instead, it looks up the session factory via JNDI right in the > action > > > class. Do I have this right? Could I use either method to grab a > > > Hibernate session? If I extend the action class to do the JNDI > look-up > > > (so I only need to write the lookup code once), would either method > > > provide a benefit over the other? > > > > > > I'm at a point where I feel like I have enough knowledge to build an > > > app, but at the same time I don't really understand the technology. > > > That's kind of precarious - I'm afraid I'm going to leave sessions > open > > > ... or something else that will cause errors and be hard to track > down. > > > > > > Thank in advance for any advice! > > > > > > > > > > > > > --------------------------------------------------------------------- > > > 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]
