Before we get down to understanding the difference between the Frames and JFrames in Java, we need to understand why and where they are used. While browsing a website, several times you might have come across a pop-up or a window with borders, buttons, text fields, etc. While in the general sense you refer to them as windows, in Java we call them Frames. A frame is a container of GUI components on it.
Then what is a JFrame? A JFrame is again a container that accommodates components like menu bars, panels, labels, text fields, buttons, and more to make the web application interactive. A Swing application has one or more JFrames.
When both are a part of GUI, then what is the difference between a Frame and JFrame in Java?
Technically speaking, Frame is an AWT component and the JFrame is a Java Swing component. But does it have any difference in rendering or functionalities? Seemingly, there is no difference between the Frame and JFrame. While Frame is platform-independent, JFrame as it is written in Java, offers platform-independent functionalities.
All GUI applications in Java need Frames or JFrames. The base windows are devoid of menu bars or borders. Using the frames or JFrames in windows, they can be resized, closed, contain various components like buttons, fields, title bars, etc. What we can say is, Java Swing JFrame offers ease of implementation and better functionalities than Frames.
Now, let’s begin with understanding what is AWT and Swing in Java before we start differentiating between Frame and JFrame.
The AWT is the Abstract Window Toolkit, an API in Java that helps the developers build the graphical user interface (GUI). It essentially helps in building the platform-dependent interfaces with the look and feel of the operating system in use. For example, the rendering is different for Windows applications, macOS, and Unix.
An AWT is a heavy-weight toolkit that has several containers such as Windows, Frame, Dialog, and Panel that extend the Container class. While Windows is more of a borderless container without any menu bars, the frame is a container more like Windows but equipped with borders and menu bars apart from buttons, text fields, etc.
Coming to Java Swing, it is also an API and a part of the Java Foundation Class (JFC) built on top of Java AWT. However, the key difference is that the containers of Java Swing are lightweight and platform-independent. Java Swing is heavily used to build windows-based applications in Java.
JFrame is one of the containers in Swing that extends the Frame class.
While Java AWT is an older toolkit for developing GUIs, Swing does not replace the AWT as one has to remember that Swing is built on top of AWT and continues to use certain base classes such as Component.
As already mentioned, a Java Frame is a top-level container in the Java AWT with borders, a close button, title bar, menu bar, alongside other components and sits on top of a Window.
The default layout of the Frame places the components in the center of the frame, however, using the methods like setLayout() of the FlowLayout class will help the developer place the buttons as per the positioning of the class.
JFrames are also similar to Frames, nevertheless the lightweight counterpart. They are a part of javax.swing package. The JFrames in Java can host more features and powerful ones than Frames, like tables, lists, scroll panes, color chooser, etc.
Java Frames and JFrames are extensively used for building GUIs in Java. While Frames offer the native, platform-dependent look and feel, the JFrames extend the platform-dependent look and feel as they are pure Java components.