Introduction to Java Swing

Features Of Swing Class  

The features of the Swing class are as follows:

• Independent of the platform.
• Looks and feels pluggable.
• The architecture is MVC.
• Components are light in weight.
• JTable, JTabbedPane, JScollPane, and other advanced features are available.
• Because Java is a platform-independent language that runs on any client machine, the look and feel of a platform-specific operating system have no bearing on an application's GUI built with Swing components.
• Lightweight Components: Its AWT supported lightweight component development starting with JDK 1.1. A component must not rely on non-Java system classes to be considered lightweight. The look and feel classes in Java help Swing components have their view.
• Pluggable Feel and Look: This feature allows users to change the appearance of Swing components without having to restart the application. The Swing library allows components to have the same look and feel across all platforms, regardless of where the programme is running. The Swing library provides an API that allows for complete control over the look and feel of an application's GUI.

Java Swing Packages

• javax.swing: Contains the core Swing components and containers such as JFrame, JPanel, JButton, and JLabel.
• javax.swing.event: Provides classes and interfaces for handling events generated by Swing components.
• javax.swing.border: Contains classes for creating and managing borders around Swing components.
• javax.swing.table:Provides classes for creating and managing tables, including JTable and TableModel.
• javax.swing.tree: Includes classes for creating and managing hierarchical data structures, such as JTree.

Components of Swing Class

• JFrame: Represents a top-level window with standard decorations, such as title bar and border.
• JPanel: A container used for grouping and organizing other components.
• JButton: A push button that can trigger actions when clicked.
• JLabel: Displays a short string or an image icon.
• JTextField: Allows user input of a single line of text.
• JTextArea: Allows user input of multiple lines of text.
• JCheckBox: A check box that can be selected or deselected.
• JRadioButton: A radio button that is part of a button group where only one button can be selected at a time.
• JComboBox: A drop-down list that allows users to select one item from a list.
• JMenuBar: A menu bar that holds menus such as JMenu for organizing menu items.

Also, read about Swing components in java, Why is Java Platform Independent

Differences Between AWT and Swing

There are many differences between Swing and Java Awt that are as follows:

Commonly used Methods of the Component class

The methods of a Component class are widely used in java swing as given below:

Hierarchy of Java Swing Classes

The Java Swing API hierarchy is shown below:

Java Swing Examples

The frame can be made in two ways:

• By creating a Frame class object (association).
• By adding to the Frame class (inheritance).

Example of Swing by Association Inside Constructor

All of the code for creating JFrame, JButton, and method calls can also be written in the java constructor.

import javax.swing.*;  
public class Simple {  
JFrame f;  
Simple(){  
f=new JFrame(); 
         
JButton p = new JButton("click");
p.setBounds(120,100,100, 40);  
         
f.add(p);  
         
f.setSize(300,400);  
f.setLayout(null);
f.setVisible(true); 
}  
 
public static void main(String[] args) {  
new Simple();  
}  
} 

In the example above, setBounds is used to set the button's position.

Simple Example of Swing by Inheritance

We can also inherit the JFrame class, so we don't have to create a JFrame instance explicitly.

import javax.swing.*;  
public class Simple2 extends JFrame{  
JFrame f;  
Simple2(){  
JButton b=new JButton("click");
b.setBounds(100,80,80, 40);  
         
add(b);  
setSize(300,400);  
setLayout(null);  
setVisible(true);  
}  
public static void main(String[] args) {  
new Simple2();  
}} 

Advantages of Java Swing

• Platform Independence: Provides a consistent look and feel across different platforms since it is written in Java.
• Rich Set of Components: Offers a wide range of sophisticated and customizable UI components like tables, trees, and tabbed panes.
• Pluggable Look-and-Feel: Allows developers to change the appearance of applications easily using different look-and-feel themes.
• Extensibility: Supports customization and extension of existing components to create complex and highly specialized user interfaces.
• Event Handling: Provides a robust event handling model through the javax.swing.event package, enabling fine-grained control over user interactions.
• Double Buffering: Reduces flicker and improves rendering performance with built-in double buffering support.

Disadvantages of Java Swing

• Performance Overhead: Swing components can be slower compared to native components due to their abstraction layer and lightweight nature.
• Complexity: Can be complex to use and configure, especially for developers unfamiliar with its extensive API and event handling.
• Memory Usage: Swing applications may consume more memory compared to AWT or native applications due to the overhead of Swing's component hierarchy.
• Look-and-Feel Consistency: Although Swing provides a consistent look-and-feel, it might not always perfectly mimic the native appearance of components on different platforms.
• Threading Issues: Requires careful management of the Event Dispatch Thread (EDT) to avoid concurrency issues and ensure thread safety in GUI updates.

Frequently Asked Questions

What are the benefits of using Swing in Java?

Swing extends the functionality of AWT-replacement components by adding new components.

Swing components can change their appearance depending on which "look and feel" library is currently in use.

Swing components adhere to the Model-View-Controller (MVC) paradigm, allowing for a much more flexible user interface.

What is MVC in Java Swing?

Swing's model-view-controller architecture (MVC) is the foundation for all of its components. MVC divides user interface components into three parts. Each of these elements has a significant impact on how the component functions. Each component's state data is included in the model.

What are the characteristics of Java Swing?

• The architecture is MVC.
• Components are light in weight.
• Independent of the platform.
• JTable, JTabbedPane, JScollPane, and other advanced features are available.

Is the Java Swing platform-dependent?

Java Swing is platform-independent.

Conclusion

Java Swing is a powerful toolkit for building platform-independent, feature-rich desktop applications in Java. With its lightweight components, pluggable look-and-feel, and advanced UI elements, Java Swing offers developers great flexibility and control over GUI design. Despite some performance trade-offs, it remains a reliable choice for creating interactive and cross-platform user interfaces.

Recommended Readings:

Timer In Java Swing

Swing Components in java

Graphics in java swing

Displaying Image in Java Swing

Using ToolTip in Java Swing