Thread problems when creating subreports

[2001 JI Open Discussion]

By: sauron - helwig

Thread problems when creating subreports

2005-01-12 08:11

Why does jasper create a new thread when creating/filling a subreport? Can I avoid this behaviour? I have a workflow/EJB problem in which the report must be created.

 

 

By: Craig O'Shannessy - shanness

RE: Thread problems when creating subreports

2005-01-12 17:04

This has come up a few times (seach this forum for ejb or threads).

 

Basically, the answer is "No", threads can't be avoided with subreports in jasper. The subreport architecture is quite clever, and makes heavy use of java threads to do the work. Ironically it's because threads are so useful for stuff like this that your not allowed to use them in EJB containers (because EJB containers reserve them the same way jasper does).

 

I also use Jasper in an EJB environment with sub-reports. I copy the entities that are going to be used into data access objects (DAO's, basically POJO's), and then jasper is accessing these safe objects rather than the entities. I still use entities directly if it's not a subreport.

 

XDoclet is a great help with EJB's, and it generates my DAO's for me.

 

Hope this helps.

 

Craig