Populating dropdownlist based on other dropdwonlist in struts 2

I have two drop-down lists that are populated from the DB. I want to populate the second drop-down dynamically based on the selected item in the first drop-down.

Can you he开发者_如何学Pythonlp me? Thanks in advance.

Struts 2 has a double select tag that can do this:

http://struts.apache.org/2.1.6/docs/doubleselect.html