Customizing Error Message in Jsp app.?

Question

Hi,
In my small application created by JDev10g wizard, I would like to customize errors received from database on dml operations before showing on jsp page. How/Where could I capture the error?
Please advise.
Thanks

Answer 1

I have the same functionality with the automatic commit in the Datahandler onEvent (update/delete and create). I ran into the same "OnEvent" problem. I think the problem is the result of having the "<jbo:Row>" tag inside of a try/catch block. From my experiments, I was able to determine that the errors almost always related to some sort of row handling. They always happened after the code within the try/catch block failed. I found that it would work fine with just the commit inside the try catch block. As soon as I tried to catch an error in the "<jbo:Row>" tag everything went screwy. This is no good considering that I have custom errors that are thrown when you try to create/update an attribute (before commiting!).
So far, I have been able to work around this somewhat. I don't get any errors if I create a Row object programitically without the Oracle convenience tags. I tested this with the OnEvent(Delete) function because it is the easiest to replicate. Here is the code that I have that works for me:
<jbo:OnEvent name="delete">
<% // get the row from the parameter jboRowKey which is created automatically when you have addRowKey=true on your URL/Form event tag (default behaviour)
Row rowDelete = ds.getRowFromKey(params.getParameter("jboRowKey")); %>
<% try { %>
// call the remove() method of the entity you can overide this method if you want (I have). To do this, check the relevant box from the entity's java tab.
rowDelete.remove();
// commit this action right away
ds.getApplicationModule().getTransaction().commit();
} catch (JboException ex) { %>
// Catching those JboExceptions we created in the EntityImpl.java file
<h3 class="error">Error</h3>
<%=ex%>
<% // since it failed, rollback the transaction. Since I am commiting everything this will only rollback the delete command. I call it just in case the framework doesn't do this somewhere else! :)
ds.getApplicationModule().getTransaction().rollback();
} %>
</jbo:OnEvent>
I haven't been able to repeat this for the update or create OnEvents because they are much more complicated. Let me know if something like this works for you! Also let me know if you find a way to do this for create/update without being far too complicated.
If you are interested to find out what the <jbo:Row> tag does (to replicate it's behaviour perhaps?) you can find the code. It should be located in this file:
C:\<jdevDir>\BC4J\src\bc4jhtmlsrc.zip
If you open it you will find RowTag.java (or something) and that is what JDeveloper runs when you use the Row tag.
Hope this helps a bit!
~Rob Lundeen