http://struts.apache.org/2.x/docs/textfield.html has the list of parameters for a textfield tag. requiredposition might be what you are looking for. The documentation says it will "Define required position of required form element (left|right)" but I have no idea if that means where the text elemnt is on the page or where the text is inside the text box.
I’ve looked at a lot of different solutions, and in my humble opinion Aspose is the way to go. Here’s the link: http://aspose.com