title: Set default focus on JButton
body: <p>I have a JButton and a JTextField on a JFrameFrom. I want to enter some data in text field and then when I press enter key, an event occurs without set focus on the button. some thing like Yahoo log-in page. You can enter username and password and without traversing the focus to the  sign-in button, when press enter, sign-in will occur. How could I do this?</p>