Java in 21 Days (8th Edition) Day 9: Creating a Graphical User Interface

Home Feedback Other Books Previous Day Next Day

Notes and Corrections

• View the Certification Practice quiz solution

• Certification answer: Answer (b) is correct. Without a default close operation such as JFrame.EXIT_ON_CLOSE, the Display application will never stop running after the frame is closed -- you must hit CTRL-C to terminate the program.

  Answer (a) is incorrect. The frame displays properly even if its size is not explicitly set. The call to the pack() statement in its constructor sets the size based on the size of the JLabel component inside the frame.

  Answer (c) is incorrect. Calling the frame's constructor inside the constructor method causes a stack overflow error when the program runs.

  Answer (d) is incorrect because (b) is correct.

Source Files

• Authenticator.java
• ButtonFrame.java
• DVR.java
• FormatFrame.java
• FormatFrame2.java
• IconFrame.java
• PasswordFrame.java
• SimpleFrame.java
• Subscriptions.java
• load.gif
• save.gif
• subscribe.gif
• unsubscribe.gif

Activities

• Solution 1: DVR.java.
• Solution 2: PasswordFrame.java.