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 for Swing

Since 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

Swing Packages

The main packages in swing are:

javax.swing.text
javax.swing.plaf.multi
javax.swing.text.html
javax.swing.text.html.parser
javax.swing.text.rtf
javax.swing.tree
javax.swing.undo
javax.accessibility
javax.swing
javax.swing.border
javax.swing.colorchooser
javax.swing.event
javax.swing.filechooser
javax.swing.plaf
javax.swing.plaf.basic
javax.swing.plaf.metal
javax.swing.plaf.synth
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 of Swing

Swing has the following advantages over AWT:

Provides both additional functionalities and added components to AWT-replacement components
Swing components are platform-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 of Swing

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.