An Applet is a small Java program that runs within a web browser. It is designed to be embedded within an HTML page and is executed on the client-side.
Table of Contents
The Applet Life Cycle
The life cycle of an Applet consists of several stages, including initialization, starting, running, stopping, and destroying.
Initialization
The init() method
The init() method is called when the applet is first loaded and is used to initialize the applet’s state.
Starting the Applet
The start() method
The start() method is called after the applet has been initialized and is used to start the applet’s execution.
Running the Applet
The paint() method
The paint() method is called whenever the applet needs to be redrawn and is responsible for rendering the applet’s user interface.
Stopping the Applet
The stop() method
The stop() method is called when the applet is stopped and is used to release any resources used by the applet.
Destroying the Applet
The destroy() method
The destroy() method is called when the applet is about to be destroyed and is used to perform any final cleanup.
Applet Security
Applet Security Model
The applet security model is designed to restrict the actions that an applet can perform on the client machine. This is done to prevent malicious applets from causing harm.
Permissions and Signing Applets
To access certain resources on the client machine, applets need to be granted permissions. Applets can also be signed to increase their trust level.
Security Restrictions on Applets
Java Applets run in a sandboxed environment, which means that they are restricted in what they can access and do on the user’s computer. This makes them more secure than traditional web applications, which run directly on the user’s computer.
How Applets differ from applications
Applets differ from traditional desktop applications in that they are executed within a web browser and have access to a restricted set of resources on the client machine. They also run within a sandboxed environment, which means that they cannot perform actions that are not explicitly allowed by the applet security model.
Conclusion
The life cycle of an Applet is a series of steps that occur from initialization to destruction. Understanding this life cycle is crucial for creating functional and secure applets.