.applet — Java Applet
Oracle (originally Sun Microsystems) · 1995
A small Java program embedded in a web page to provide interactive content or functionality directly in the browser.
Key Features
- Runs within a web browser, extending web page capabilities.
- Written in the Java programming language, offering object-oriented features.
- Can perform complex tasks, animations, and interactive elements.
- Requires a Java Runtime Environment (JRE) installed on the user's system.
Best For
- Providing rich, platform-independent interactivity on older websites.
- Developing complex graphical applications that needed to run in a browser before modern web technologies matured.
- Creating educational tools and simulations with graphical interfaces.
Less Ideal For
- Modern web development due to security risks and declining browser support.
- Applications requiring direct access to the user's file system or advanced hardware features.
- Mobile applications, as applets are not designed for mobile browsers.
- Standalone desktop applications, which are better served by Java applications or other native executables.
Common Use Cases
- Interactive educational content and simulations.
- Browser-based games with rich graphics.
- Data visualization and interactive charts.
- Early forms of web-based multimedia applications.
How to Open It
- Modern web browsers typically do not support Java Applets due to security vulnerabilities and lack of updates.
- To run an applet, you would historically need a browser with Java plugin support and a correctly installed Java Runtime Environment (JRE).
- Specific legacy applications or development environments might still allow execution for testing or debugging purposes.
- Consider using alternative technologies like JavaScript, WebAssembly, or modern frameworks for current web interactivity.
What is a .applet file?
A Java Applet is a small Java program designed to run within a web browser. Unlike standalone Java applications, applets are embedded into web pages and execute directly in the user's browser environment. They can provide interactive content, games, and complex graphical interfaces that go beyond what traditional HTML and JavaScript could offer at the time of their peak popularity. However, security concerns and the rise of alternative technologies have led to their decline.
Programs That Open .applet Files
| Platform | Program | ||
|---|---|---|---|
| Windows | Internet Explorer (with Java plugin) | Free | |
| Eclipse IDE (for development) | Free | ||
| macOS | Safari (with Java plugin) | Free | |
| IntelliJ IDEA (for development) | Paid | ||
| Linux | Firefox (with Java plugin) | Free | |
| NetBeans IDE (for development) | Free |
Common Problems with .applet Files
Frequently Asked Questions
No, Java Applets are largely obsolete due to security concerns, lack of support in modern browsers, and the rise of more capable web technologies like JavaScript frameworks and WebAssembly.
A Java Applet is designed to run within a web browser and is embedded in a web page, whereas a Java Application is a standalone program that runs directly on the operating system.
Major security vulnerabilities, poor performance, and the inconvenience of requiring a separate Java plugin led to their deprecation by browser vendors and Oracle.
Technical Details
Java Applets are compiled Java bytecode, typically packaged as `.class` files or within `.jar` archives. They are executed by a Java Virtual Machine (JVM) that is integrated into the web browser. The applet's behavior is controlled by the `Applet` class in the Java API, and they often interact with the HTML document through specific JavaScript bridges.