Section 64

1
Chapter 3

• Section 64
• Manipulating Data Using Methods Java
  Swing

2
Chapter Objectives

• Use Swing components to build the GUI for a Swing
  program
• Use the exit() method to close a Swing program
• Implement an ActionListener to handle events

3
Using Swing Components

• Make a copy of your BodyMass.java program.
• Right click on BodyMass.java and select copy
• Paste a copy Right click on bodymasscalculator

4
Using Swing Components

• Import the javax.swing.JOptionPane class
• Contains methods to create dialog boxes for
  input, confirmation, and messages
• Delete the IOException and BufferedReader code
• The swing dialog boxes buffer data from the user
  and handle IO errors

5
Swing Dialog Boxes

• Dialog boxes are created with the JOptionPane
  show methods
• The showInputDialog() and showConfirmDialog
  return a String containing the user input

6
Swing Dialog Boxes

7
Closing Programs that use Swing

• System.exit() terminates an application that
  displays a GUI
• The command prompt window closes when this method
  is called
• System.exit accepts an integer argument that
  serves as a status code
• 0 indicates successful termination
• 1 indicates abnormal termination

8
Saving, Compiling, and Running the Swing Version

• Compile the source code
• Test with the same sample data for all versions
  to compare output results
• If incorrect or unrealistic data is entered by
  the user, errors will occur
• Errors and exception handling will be discussed
  in a later chapter

9
Summary

• Java Swing code allows the programmer to easily
  display pop up windows to get input and to
  display output.

10
Rest of Today

• Complete the swing version of the Bass Mass
  Calculator
• Test your results
• Show me the program when it is complete