在编写Selenium测试时如何将UI对象标识符与测试脚本分离

I'm planning on writing some test scripts for a J2EE app using Selenium. The PageObject pattern sounds pretty good as it allows a clean seperation between test logic and implementation. How can I maintain the identifiers for each UI element in the app, coding them within the PageObject doesn't sound too good. Creating a repository of all the UI elements and their identifiers - whether it be id,xpath or other - within the app sounds nice, what would be best way to do it?I'm planning on writing some test scripts for a