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.
You can use Java reflection (java.lang.reflect.*) to obtain the names of all the variables, and refer to them by name. I'm not sure why you would want to, but that's the java feature that enables that kind of manipulation.
I would be more interested in Eclipse's feature to change all the uses of one name of a variable to something else, throughout a project.