This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
Your Payment class should have a proper overriden toString() (and hashCode() too if you use this class in collection classes which use hash code)method which returns a String representing the object in a meaningful text. This is not related to Struts or Tomcat, so might better sit in the JIG forum.