在这个界面，有一个主要的控制机制，在数字键盘上的按钮。按“0”完成当前单词的录入和创建一个空间，准备下一个单词的输入。

-In this GUI, there is one main control mechanism, the buttons in the numeric keypad. The message appears in the text window at the top. By pressing the button “2”, you will get one of “a”, “b”, or “c”. To cycle through the words (or prefixes of words) that match, the user clicks the button labelled “*”. Pressing “0” completes the entry of the current word and creates a space, ready for the entry of the next word.

You can add other features if you wish, such as a “C” button for clearing the last typed character, a drop-down menu for the list of words that match, up/down buttons to scroll through the menu etc. Feel free to practice working with the Swing API.