How do I submit multiple models in Struts 2?

Question

I have a JSP that allows users to dynamically create additional form fields to create multiple objects. Perhaps I want to allow users to be able to submit as many line items as they want when submitting an invoice form.

How do I create a Struts 2 Action that will be able to take in an ArrayList populated with objects created from those dynamically generated fields.

Answer 1

You should read the Tabular input guide.

Answer 2

According to the (ever-poor) documentation, which forces you to try to extrapolate the information you want, rather than just telling you authoritatively (and assuming you're really asking about Struts' built-in type conversion), your form fields would need to be named something like...

someList.makeNew(0).someField1
someList.makeNew(0).someField2
...
someList.makeNew(1).someField1
someList.makeNew(1).someField1
...

...and you would then need to set up an ActionClassName-conversion.properties file to let the type converter know how to handle type conversion for fields which begin with "someList".

The only time I actually tried this myself, I had trouble getting it working with Lists and ended up having to use Maps.

Here's a useful blog entry about modifying a Map of objects using type conversion - I haven't had much luck finding useful information about the "makeNew" field name format the documentation mentions, but this might help you get started.