Hello Steve! I have done some trial and error and come to the following (if not somewhat shaky) conclusion.
If I make the call to the datasource in the consturctor of my object it will fail, since the caller is the server itself and it has no context. If I make the call to the datasource as a method after have looked up my object and retrived as a "user" it will run in the context of the user (web-app) and therefore work. Perhaps Yoav can confirm this? So, I manage to get my object...but get a strange class cast error.... This code: System.out.println(o); se.alfamoving.file.db.FileIdGenerator fg = (se.alfamoving.file.db.FileIdGenerator) o; Gives this output: [EMAIL PROTECTED] java.lang.ClassCastException <snip/> But I'll guess that I spelled badly somewhere :-/ The happy moments never seems to last :-) Thank you very much for your time and effort! Regards Roland Carlsson Den 04-10-27 14.28, skrev "Steve Kirk" <[EMAIL PROTECTED]>: > OK now I see your problem. I have the same issue. I've worked around it > with a bit of a hack I'm afraid, and just used the MySQL non-jdbc solution. > As you say I will pay the price for this sin later, if I ever need to swap > database. However I've taken a view that for my specific situation, this is > unlikely in the medium term. So instead of investing time in making the > code completely portable to another database, I've invested time in > mitigating the impact by genericising my code so that there is only one > place I will need to make changes. (Essentially, I've beanified all my > database tables so that I have a single method that creates rows in any > table in the database and returns the ID). > > I think portability and re-use are worth investing time and effort in, but > there is a limit to that, and sometimes, you need to make compromises and > move on, otherwise you can spend days trying to work around a problem that > might never happen. > >> -----Original Message----- >> From: Roland Carlsson [mailto:[EMAIL PROTECTED] >> Sent: Wednesday 27 October 2004 13:03 >> To: TomcatUsers >> Subject: Sv: GlobalNamingResouces used by other GlobalNamingResources >> >> >> Hi Steve and thanks for you answer. >> >> Try the following scenario. >> >> The problem is to get back the primary key when doing an >> insert. Say that >> you have a master/slave relation between two tables. >> >> You insert a row into master. Then you are going to insert a few rows >> connected to the master into slave. How do you know the >> id-number of your >> master? >> >> I know that mysql has a non-jdbc soloution for this but since >> one of our >> general design goals are portable code...... So, we have >> desided to take the >> same apporach as Object-Relational Bridge. We created our own >> id-generator >> to handle the problem. But its has created a new set of >> problems now when we >> are going to use multiple web-apps and (in a not so distant >> future) mutiple >> servers. >> >> Regards >> Roland Carlsson >> >> >> >> >> Den 04-10-27 13.48, skrev "Steve Kirk" >> <[EMAIL PROTECTED]>: >> >>> sorry, can't answer specific Q on whether you can access >> datasource from >>> generator. but it sounds like you are trying to uniquely >> ID rows in a >>> database? >>> >>> if so then the simplest way seems to be to use >> auto_increment fields and let >>> the database handle it. or are you saying that that isn'y >> working - is this >>> what you mean by "not supporting the database-generated >> id-numbers"? if so >>> please say more about why its not working. what database? >> code sample? >> >> >> --------------------------------------------------------------------- >> 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] > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
