This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
What do you mean by "add an "Enter Key Value" in a input field" - do you want to wait until the field has been populated, and then append a newline (or carriage return character) to it? if so, I think you can add an ActionListener to it; that will be called whenever the contents of the field change.