Hi, I also use hibernate in dispatcher and some strange errors occurs, after debugging whole day without any result, I commented out c3p0, and it works, from there I proceeded, looks like disabling c3p0 is a good debugging method when hibernate is giving out strange errors.
Chris Lewis-5 wrote: > > Yep, that solved it. > > <property name="hibernate.c3p0.max_statements">0</property> > > After that prepared statements work as normal. Doesn't the > hibernate.c3p0.max_statements directive help improve performance though? > I mean, wouldn't it if it didn't fall over ... ;-) > > Thanks Martijn, I'm glad I'm not crazy and will know to be wary of it in > the future. > > chris > > Martijn Brinkers wrote: >> This posting also report similar problems and it was 'solved' by >> disabling the statement cache. >> >> https://jira.jboss.org/jira/browse/JBPORTAL-1287 >> >> >> Martijn >> >> On Thu, 2008-07-24 at 22:57 -0700, Martijn Brinkers (List) wrote: >> >>> Sounds to me something related to the PreparedStatement cache. Do you >>> use c3po? If so did you specify hibernate.c3p0.max_statements? >>> >>> Martijn >>> >>> >>> On Thu, 2008-07-24 at 23:26 -0400, Chris Lewis wrote: >>> >>>> Ok, I've figured out what exactly is causing it and how to work around >>>> it. I can't say why, but perhaps a resident hibernate guru will know >>>> (it >>>> may even be a know issue or gotcha). First off, the quick fix. This >>>> query (and variations like load(), get(), and using the criteria api) >>>> cause the problem: >>>> >>>> Listing listing = (Listing)session.createQuery("from Listing >>>> lst >>>> where lst.id=:id") >>>> .setLong("id", Long.valueOf(sListingId)).uniqueResult(); >>>> >>>> This works as expected: >>>> >>>> Listing listing = (Listing)session.createQuery("from Listing >>>> lst >>>> where lst.id=" + sListingId) >>>> .uniqueResult(); >>>> >>>> It seems to come down to how hibernate handles the query results when >>>> the query is formed with a "raw" HQL string vs something like get(), >>>> load(), the criteria api, or using query parameters as I was initially >>>> doing. It also has something to do with the field being queried and >>>> seems to happen only on fields that exist in each of the tables. In my >>>> case the abstract super class Listing has the PK field "id", and the 2 >>>> subclasses also have a PK field named "id." Querying by any method >>>> other >>>> than "constructed strings" leads to the issue, while querying on >>>> another >>>> field in the super class, whose name is unique to that class, works >>>> fine. >>>> >>>> So the BIG question is why in the world does it work the first time and >>>> continue to work until the value one queries by changes? >>>> >>>> I'd also like to know if anyone has seen this before, and/or if it's a >>>> known issue. I'm using a slightly outdated version of hibernate >>>> (3.2.2.ga) and for all I know this may be fixed in more recent >>>> versions. >>>> My wrists are shot so I'll try tomorrow. If anyone knows of this or >>>> gets >>>> interested/bored enough to try it, please let me know. >>>> >>>> Thanks tons for all of your input. >>>> >>>> Sincerely, >>>> Chris Lewis >>>> >>>> Chris Lewis wrote: >>>> >>>>> Hello, >>>>> >>>>> I have a dispatcher that uses a hibernate session. The dispatcher is >>>>> auto bound and receives the session in the constructor. I'm using >>>>> tapestry-hibernate so that session instance is a proxy that gets the >>>>> real session for the current thread (right?). Now in testing my >>>>> dispatcher, I give it a url like: >>>>> >>>>> /MyContext/?limg=2 >>>>> >>>>> The dispatcher looks for "limg" and if found, queries the session >>>>> assuming that its value is the PK of a mapped entity. When I trigger >>>>> the >>>>> dispatcher for the first time it works fine. If I refresh the page, >>>>> fine. If I change the value to something else, say 3, then it breaks >>>>> with a org.hibernate.InstantiationException: >>>>> >>>>> Cannot instantiate abstract class or interface: >>>>> com.mypackage.data.Listing >>>>> >>>>> If I change the value back to 2, the same thing happens! "Listing" is >>>>> an >>>>> abstract class mapped as a super class entity via: >>>>> >>>>> @Entity >>>>> @Inheritance(strategy = InheritanceType.JOINED) >>>>> >>>>> Any clue what's going on here? Two things are perplexing me: >>>>> >>>>> 1) Querying mapped super classes is legal, and I in fact the same >>>>> thing >>>>> on my Index page with no problem. >>>>> 2) The query works the first time, but as soon as the id changes it is >>>>> forever broken until I restart the container. >>>>> >>>>> Thanks in advance! >>>>> >>>>> chris >>>>> >>>>> >>>>> >> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: [EMAIL PROTECTED] >> For additional commands, e-mail: [EMAIL PROTECTED] >> >> >> > > -- > http://thegodcode.net > > > -- View this message in context: http://www.nabble.com/T5.0.14-SNAPSHOT%3A-strange-behavior-Dispatcher-when-using-a-Session-tp18624780p18652304.html Sent from the Tapestry - User mailing list archive at Nabble.com. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
