Swing is a GUI widget toolkit for Java. It is part of Oracle’s Java Foundation Classes (JFC) – an API for providing a graphical user interface (GUI) for Java programs. Swing was developed to provide a more sophisticated set of GUI components than the earlier Abstract Window Toolkit (AWT). JAVA provides a rich set of libraries to create Graphical User Interface in platform independent way.
Swing API is set of extensible GUI Components to ease developer’s life to create JAVA based Front End/ GUI Applications. It is build upon top of
AWT API and acts as replacement of AWT API as it has almost every control corresponding to AWT controls. Swing component follows a Model-View-Controller architecture to fulfill the following criteria.
- A single API is to be sufficient to support multiple look and feel.
- API is to model driven so that highest level API is not required to have the data.
- API is to use the Java Bean model so that Builder Tools and IDE can provide better services to the developers to use it.
2. JAVA Swing
Unlike AWT, Java Swing provides platform-independent and lightweight components. The
javax.swing package provides classes for java swing API such as
2.1 MVC Architecture
Swing API architecture follows loosely based MVC architecture in the following manner.
- A Model represents component’s data.
- View represents visual representation of the component’s data.
- Controller takes the input from the user on the view and reflects the changes in Component’s data.
- Swing component have Model as a separate element and View and Controller part are clubbed in User Interface elements. Using this way, Swing has pluggable look-and-feel architecture.
Every user interface considers the following three main aspects:
- UI elements : These are the core visual elements the user eventually sees and interacts with. GWT provides a huge list of widely used and common elements varying from basic to complex.
- Layouts: They define how UI elements should be organized on the screen and provide a final look and feel to the GUI (Graphical User Interface).
- Behavior: These are events which occur when the user interacts with UI elements.
2.2 Swing Features
- Light Weight – Swing component are independent of native Operating System’s API as Swing API controls are rendered mostly using pure JAVA code instead of underlying operating system calls.
- Rich controls – Swing provides a rich set of advanced controls like Tree, TabbedPane, slider, colorpicker, table controls.
- Highly Customizable – Swing controls can be customized in very easy way as visual apperance is independent of internal representation.
- Pluggable look-and-feel– SWING based GUI Application look and feel can be changed at run time based on available values.
Popular Java Editors:
To write your java programs you will need a text editor. There are even more sophisticated IDE available in the market. But for now, you can consider one of the following:
- Notepad: On Windows machine you can use any simple text editor like Notepad TextPad.
- NetBeans: is a Java IDE that is open source and free which can be downloaded from http://www.netbeans.org/index.html.
- Eclipse: is also a java IDE developed by the eclipse open source community and can be downloaded from http://www.eclipse.org
This example is developed on Eclipse therefore a compatible Eclipse IDE is required to be installed on the system.
We also need WindowBuilder tool to be installed on Eclipse IDE for the easiness of the work. To learn how to install WindowBuilder tool please visit the Setup section 2.1 of the following link click here.
2.4 Creating Menus
The following code creates the menus shown near the beginning of this menu section. Because this code has no event handling, the menus do nothing useful except to look as they should. If you run the example, you’ll notice that despite the lack of custom event handling, menus and submenus appear when they should, and the check boxes and radio buttons respond appropriately when the user chooses them.
2.5 Class and description
- Component: A Component is the abstract base class for the non menu user-interface controls of SWING. Component represents an object with graphical representation.
- Container: A Container is a component that can contain other SWING components.
- JComponent: A JComponent is a base class for all swing UI components. In order to use a swing component that inherits from JComponent, component must be in a containment hierarchy whose root is a top-level Swing container.
3. Swing Java Calculator Example
This tutorial is about how to make a calculator in Java. Below I have shared the simple calculator program in java using swing. It is a simple calculator in Java which can perform basic arithmetic operations like addition, subtraction, multiplication and division of two numbers.
Output of code will be like the one below.
4. Download the Source Code
This was an example of java calculator example.
You can download the full source code of this example here: Java Calculator using Swing Example