Introduction To Swing In Java

Introduction

In this article we discuss Java Swing as used for "Graphics programming in Java". We discuss the basic classes of Swing, why we use it, its advantages and a comparison with AWT.

Swing in Java

It is a Java Graphical User Interface (GUI) toolkit.  It is an Application Programming Interface (API) for providing a Graphical User Interface (GUI) for Java programs.

It is a part of the JFC (Java Foundation Classes), that is an API for providing a graphical user interface for Java programs.

It is used to create a GUI with Java.

Need of Swing

Siince we already have a class AWT for a GUI, why do we need Swing for GUI? Here are some points that describe the need of Swing:

• lightweight
• configurable
• platform independent
• customizable
• extensible

Swing Hierarchy

Packages

The main packages in swing are:

1. javax.swing.text
2. javax.swing.plaf.multi
3. javax.swing.text.html
4. javax.swing.text.html.parser
5. javax.swing.text.rtf
6. javax.swing.tree
7. javax.swing.undo
8. javax.accessibility
9. javax.swing
10. javax.swing.border
11. javax.swing.colorchooser
12. javax.swing.event
13. javax.swing.filechooser
14. javax.swing.plaf
15. javax.swing.plaf.basic
16. javax.swing.plaf.metal
17. javax.swing.plaf.synth
18. javax.swing.table

It is an update GUI toolkit. It adds various components to our window frame like lables, buttons, scrollbars, tables and trees.

Example

In this program we make a simple window without any extra features or functionality.

importjavax.swing.JFrame;
importjavax.swing.SwingUtilities;
publicclass Example123extends JFrame
  {
    publicExample123()
      {
        setTitle("Just a simple program of Java Swing");
        setSize(425, 350 );
        setLocationRelativeTo(null);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
      }
publicstatic voidmain(String[]args)
  {
    SwingUtilities.invokeLater(newRunnable()
      {
        publicvoid run()
          {
            Example123esw =new Example123();
            esw.setVisible(true);
          }
          });
      }
  }

Output

When we run our program, a window will be generated that is like the following window:

javac Example123.java

java Example123

Advantages

Swing has the following advantages over AWT:

• Provides both additional functionality and added components to AWT-replacement components

• Swing components are plateform independent.

• Swing components can use a different look and feel.

• Swing components use the Model-View-Controller paradigm (MVC), and thus can provide a much more flexible UI.

• Swing components are lightweight (are less resource intensive than AWT).

• Swing provides built-in double buffering.

• Swing provides paint debugging support for when you build your own components.

Disadvantages

Swing has a few disadvantages; they are:

• it can be slower than AWT (all components are drawn) as if we're not careful in programming.

• It requires Java 1.2 or a separate JAR file.

• Swing components that look like native components might not act exactly like native components.