Applet

Last updated

In computing, an applet is any small application that performs one specific task that runs within the scope of a dedicated widget engine or a larger program, often as a plug-in. [1] The term is frequently used to refer to a Java applet, a program written in the Java programming language that is designed to be placed on a web page. Applets are typical examples of transient and auxiliary applications that do not monopolize the user's attention. Applets are not full-featured application programs, and are intended to be easily accessible.

Contents

History

The word applet was first used in 1990 in PC Magazine . [2] However, the concept of an applet, or more broadly a small interpreted program downloaded and executed by the user, dates at least to RFC 5 (1969) by Jeff Rulifson, which described the Decode-Encode Language, which was designed to allow remote use of the oN-Line System over ARPANET, by downloading small programs to enhance the interaction. [3] This has been specifically credited as a forerunner of Java's downloadable programs in RFC 2555. [4]

Applet as an extension of other software

In some cases, an applet does not run independently. These applets must run either in a container provided by a host program, through a plugin, or a variety of other applications including mobile devices that support the applet programming model.

Web-based applets

Applets were used to provide interactive features to web applications that historically could not be provided by HTML alone. They could capture mouse input and also had controls like buttons or check boxes. In response to the user action, an applet could change the provided graphic content. This made applets well suited for demonstration, visualization, and teaching. There were online applet collections for studying various subjects, from physics to heart physiology. Applets were also used to create online game collections that allowed players to compete against live opponents in real-time.

An applet could also be a text area only, providing, for instance, a cross-platform command-line interface to some remote system. If needed, an applet could leave the dedicated area and run as a separate window. However, applets had very little control over web page content outside the applet dedicated area, so they were less useful for improving the site appearance in general (while applets like news tickers or WYSIWYG editors are also known). Applets could also play media in formats that are not natively supported by the browser.

HTML pages could embed parameters that were passed to the applet. Hence, the same applet could appear differently depending on the parameters that were passed.

Examples of Web-based applets include:[ citation needed ]

Applet Vs. Subroutine

A larger application distinguishes its applets through several features:[ citation needed ]

Java applets

A Java applet is a Java program that is launched from HTML and run in a web browser. It takes code from server and run in a web browser. It can provide web applications with interactive features that cannot be provided by HTML. Since Java's bytecode is platform-independent, Java applets can be executed by browsers running under many platforms, including Windows, Unix, macOS, and Linux. When a Java technology-enabled web browser processes a page that contains an applet, the applet's code is transferred to the client's system and executed by the browser's Java virtual machine. [5] An HTML page references an applet either via the deprecated <applet> tag or via its replacement, the <object> tag. [6]

Security

Recent developments in the coding of applications, including mobile and embedded systems, have led to the awareness of the security of applets.

Open platform applets

Applets in an open platform environment should provide secure interactions between different applications. A compositional approach can be used to provide security for open platform applets. [7] Advanced compositional verification methods have been developed for secure applet interactions. [7]

Java applets

A Java applet contains different security models: unsigned Java applet security, signed Java applet security, and self-signed Java applet security.

Web-based applets

In an applet-enabled web browser, many methods can be used to provide applet security for malicious applets. A malicious applet can infect a computer system in many ways, including denial of service, invasion of privacy, and annoyance. [8] A typical solution for malicious applets is to make the web browser to monitor applets' activities. This will result in a web browser that will enable the manual or automatic stopping of malicious applets. [8]

See also

Related Research Articles

<span class="mw-page-title-main">Common Gateway Interface</span> Interface between Web servers and external programs

In computing, Common Gateway Interface (CGI) is an interface specification that enables web servers to execute an external program to process HTTP or HTTPS user requests.

<span class="mw-page-title-main">Java applet</span> Small application written in Java

Java applets are small applications written in the Java programming language, or another programming language that compiles to Java bytecode, and delivered to users in the form of Java bytecode.

<span class="mw-page-title-main">Java (programming language)</span> Object-oriented programming language

Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. It is a general-purpose programming language intended to let programmers write once, run anywhere (WORA), meaning that compiled Java code can run on all platforms that support Java without the need to recompile. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture. The syntax of Java is similar to C and C++, but has fewer low-level facilities than either of them. The Java runtime provides dynamic capabilities that are typically not available in traditional compiled languages.

<span class="mw-page-title-main">Java virtual machine</span> Virtual machine that runs Java programs

A Java virtual machine (JVM) is a virtual machine that enables a computer to run Java programs as well as programs written in other languages that are also compiled to Java bytecode. The JVM is detailed by a specification that formally describes what is required in a JVM implementation. Having a specification ensures interoperability of Java programs across different implementations so that program authors using the Java Development Kit (JDK) need not worry about idiosyncrasies of the underlying hardware platform.

<span class="mw-page-title-main">Curl (programming language)</span>

Curl is a reflective object-oriented programming language for interactive web applications, whose goal is to provide a smoother transition between content formatting and computer programming. It makes it possible to embed complex objects in simple documents without needing to switch between programming languages or development platforms. The Curl implementation initially consisted of an interpreter only; a compiler was added later.

Java Platform, Standard Edition is a computing platform for development and deployment of portable code for desktop and server environments. Java SE was formerly known as Java 2 Platform, Standard Edition (J2SE).

In computing, cross-platform software is computer software that is designed to work in several computing platforms. Some cross-platform software requires a separate build for each platform, but some can be directly run on any platform without special preparation, being written in an interpreted language or compiled to portable bytecode for which the interpreters or run-time packages are common or standard components of all supported platforms.

A computing platform, digital platform, or software platform is the infrastructure on which software is executed. While the individual components of a computing platform may be obfuscated under layers of abstraction, the summation of the required components comprise the computing platform.

<span class="mw-page-title-main">ActiveX</span> Software framework by Microsoft introduced in 1996

ActiveX is a deprecated software framework created by Microsoft that adapts its earlier Component Object Model (COM) and Object Linking and Embedding (OLE) technologies for content downloaded from a network, particularly from the World Wide Web. Microsoft introduced ActiveX in 1996. In principle, ActiveX is not dependent on Microsoft Windows operating systems, but in practice, most ActiveX controls only run on Windows. Most also require the client to be running on an x86-based computer because ActiveX controls contain compiled code.

A Rich Internet Application is a web application that has many of the characteristics of desktop application software. The concept is closely related to a single-page application, and may allow the user interactive features such as drag and drop, background menu, WYSIWYG editing, etc. The concept was first introduced in 2002 by Macromedia to describe Macromedia Flash MX product. Throughout the 2000s, the term was generalized to describe browser-based applications developed with other competing browser plugin technologies including Java applets, Microsoft Silverlight.

A user interface markup language is a markup language that renders and describes graphical user interfaces and controls. Many of these markup languages are dialects of XML and are dependent upon a pre-existing scripting language engine, usually a JavaScript engine, for rendering of controls and extra scriptability.

In computing, Java Web Start is a deprecated framework developed by Sun Microsystems that allows users to start application software for the Java Platform directly from the Internet using a web browser. The technology enables seamless version updating for globally distributed applications and greater control of memory allocation to the Java virtual machine.

A webform, web form or HTML form on a web page allows a user to enter data that is sent to a server for processing. Forms can resemble paper or database forms because web users fill out the forms using checkboxes, radio buttons, or text fields. For example, forms can be used to enter shipping or credit card data to order a product, or can be used to retrieve search results from a search engine.

Comet is a web application model in which a long-held HTTPS request allows a web server to push data to a browser, without the browser explicitly requesting it. Comet is an umbrella term, encompassing multiple techniques for achieving this interaction. All these methods rely on features included by default in browsers, such as JavaScript, rather than on non-default plugins. The Comet approach differs from the original model of the web, in which a browser requests a complete web page at a time.

<span class="mw-page-title-main">Java (software platform)</span> Set of computer software and specifications

Java is a set of computer software and specifications that provides a software platform for developing application software and deploying it in a cross-platform computing environment. Java is used in a wide variety of computing platforms from embedded devices and mobile phones to enterprise servers and supercomputers. Java applets, which are less common than standalone Java applications, were commonly run in secure, sandboxed environments to provide many features of native applications through being embedded in HTML pages.

<span class="mw-page-title-main">Google Web Toolkit</span> Free Java library

Google Web Toolkit, or GWT Web Toolkit, is an open-source set of tools that allows web developers to create and maintain JavaScript front-end applications in Java. It is licensed under Apache License 2.0.

A software widget is a relatively simple and easy-to-use software application or component made for one or more different software platforms.

<span class="mw-page-title-main">Abstract Window Toolkit</span> Java-based GUI toolkit

The Abstract Window Toolkit (AWT) is Java's original platform-dependent windowing, graphics, and user-interface widget toolkit, preceding Swing. The AWT is part of the Java Foundation Classes (JFC) — the standard API for providing a graphical user interface (GUI) for a Java program. AWT is also the GUI toolkit for a number of Java ME profiles. For example, Connected Device Configuration profiles require Java runtimes on mobile telephones to support the Abstract Window Toolkit.

An Internet operating system, or Internet OS, is any type of operating system designed to run all of its applications and services through an Internet client, generally a web browser. The advantages of such an OS would be that it would run on a thin client, allowing cheaper, more easily manageable computer systems; it would require all applications to be designed on cross-platform, open standards; and would not tie a user's applications, documents, and preferences to a single computer, but rather place them in the Internet cloud. The Internet OS has also been promoted as the perfect type of platform for software as a service.

Upload components are software products that are designed to be embedded into a web site to add upload functionality to it. Upload components are designed to replace the standard HTML4 upload mechanism. Compared with HTML4, Upload Components have a more user-friendly interface and support a wider range of features.

References

  1. ↑ "AskOxford: applet", Oxford Dictionaries. Accessed on July 21, 2009
  2. ↑ "Oxford English Dictionary". 2011. Retrieved 2011-08-23.
  3. ↑ Rulifson, Jeff (June 2, 1969), "DEL", RFC 5 , Network Working Group
  4. ↑ RFC editor, et al. (April 7, 1999), "30 Years of RFCs", RFC 2555 , Network Working Group
  5. ↑ "Applets". oracle.com. October 5, 2023. Retrieved October 5, 2023.
  6. ↑ "HTML applet tag", W3Schools. Access on July 21, 2009
  7. 1 2 Barthe, Gilles; Gurov, Dilian; Huisman, Marieke (2002). "Compositional Verification of Secure Applet Interactions". Fundamental Approaches to Software Engineering. Lecture Notes in Computer Science. Vol. 2306. pp. 15–32. CiteSeerX   10.1.1.16.1254 . doi:10.1007/3-540-45923-5_2. ISBN   978-3-540-43353-8.
  8. 1 2 Hassler, Vesna; Then, Oliver (1998). "Controlling Applets' Behavior in a Browser". Proceedings 14th Annual Computer Security Applications Conference (Cat. No.98EX217). pp. 120–125. doi:10.1109/CSAC.1998.738594. ISBN   978-0-8186-8789-1. S2CID   17633591.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.