| ## Java 1.1 Unleashed # Glossary accessor method A public method defined in a bean that reads or writes the value of a property. ActiveX A family of technologies developed by Microsoft to combine computing ability with Internet connectivity. ActiveX control A software module with OLE capabilities that can easily be embedded in Web pages or programs. anchor A part of a hypertext document that is either the source or destination of a hypertext link. A link can extend from an anchor to another document, or from another document to an anchor. When anchors are the starting points of these links, they are typically highlighted or otherwise identified in the hypertext browser as hotspots. API (Application Programming Interface) The set of Java packages and classes--included in the Java Development Kit (JDK)--that programmers use to create applets. applet A Java program that can be included in an HTML page with the `APPLET` element and observed in a Java-enabled browser. application (Java) A computer program, written in Java, that executes independently of a Java-enabled browser through the Java interpreter included in the Java Development Kit. ASCII (American Standard Code for Information Interchange) A 7-bit character code that can represent 128 characters, some of which are control characters used for communications control and cannot be printed. attribute A property of an HTML element, specified in the start tag of the element. The attribute list of the `APPLET` element is used to identify the location of applet source code (with the `Codebase` attribute) and the name of the Java class (with the `Code` attribute). bean A compact, portable, reusable, serializable, Java software component that includes support for automatic integration with visual application builder tools. block (Java) The code between matching curly braces `{` and `}`. boolean A data type that has a value of `true` or `false`. bound property A JavaBeans property that provides notifications to an interested party based on changes in its value. browser A software program used to observe the Web. Also a synonym for a Web client. bytecode The machine-readable code created as the result of compiling a Java language source file. This is the code distributed across the network to run an applet. Bytecodes are architecture neutral; the Java-capable browser ported to a particular platform interprets them. cast (verb) To change an expression from one data type to another. CERN (Centre European pour la Recherche Nucleaire) The European laboratory for particle physics, where the World Wide Web originated in 1989. (See `http://www.cern.ch/`.) CGI (Common Gateway Interface) A standard for programs to interface with Web servers. child class A subclass of a class (its parent class). It inherits `public` and `protected` data and methods from the parent class. class A template for creating objects. A class defines data and methods and is a unit of organization in a Java program. It can pass its `public` data and methods to its subclasses. client A software program that requests information or services from another software application (server) and displays this information in a form required by its hardware platform. COM (Component Object Model) A binary standard developed by Microsoft for representing software components in a distributed environment. compiler A software program that translates human-readable source code into machine- readable code. constrained property A JavaBeans property that allows an interested party to perform a validation on a new property value before accepting the modification. constructor A method named after its class. A constructor method is invoked when an object of that class is made. container A context in which components can be grouped together and interacted with. content handler A program loaded into the user's HotJava browser that interprets files of a type defined by the Java programmer. The Java programmer provides the necessary code for the user's HotJava browser to display and interpret this special format. CORBA (Common Object Request Broker Architecture) The industry standard for representing distributed objects. CPU Central Processing Unit. cross-platform A term used to indicate that a piece of software can run on any operating system platform. customizer A user interface that provides a specialized way of visually editing bean properties. design patterns Rules used to determine information about a bean from its reflected method names and signatures. digital signature A security technique that involves the attachment of a code to a software component that identifies the vendor of the component. domain name The alphanumeric name for a computer host; this name is mapped to the computer's numeric Internet Protocol (IP) address. DTD (Document Type Definition) A specification for a markup language such as HTML. element A unit of structure in an HTML document. Many elements have start and stop tags; some have just a single tag, and some can contain other elements. event Something that happens within a component that an application or other component may want to know about and possibly react to. event adapter An intermediary placed between an event source and a listener that provides additional event delivery behavior. event listener An applet, application, or JavaBeans component capable of responding to events. event source A component capable of generating events. event state object An object used to store information associated with a particular event. externalization mechanism A way to store and retrieve an object through some type of customized, externally defined format. FTP (File Transfer Protocol) A way to exchange files across a network. garbage collection The process by which memory allocated for objects in a program is reclaimed. Java automatically performs this process. getter method An accessor method that reads, or gets, the value of a property. Gopher A protocol for disseminating information on the Internet using a system of menus. home page An entry page for access to a local web. Also, a page that a person or company defines as a principal page, often containing links to other pages containing personal or professional information. HotJava A Web browser designed to execute applets written in the Java programming language. hotspot An area on a hypertext document that a user can click to retrieve another resource or document. HTML (HyperText Markup Language) The mechanism used to create Web pages. Web browsers display these pages according to a browser-defined rendering scheme. HTTP (HyperText Transfer Protocol) The native protocol of the Web, used to transfer hypertext documents. hypermedia Hypertext that includes multimedia: text, graphics, images, sound, and video. hypertext Text that is not constrained to a single sequence for observation; Web-based hypertext is not constrained to a single server for creating meaning. imagemap A graphic inline image on an HTML page that potentially connects each pixel or region of an image to a Web resource. The user retrieves the resources by clicking the image. indexed properties A property that represents an array of values. inner class A Java class defined as a member of another class, locally within a block of statements or anonymously within an expression. instance An object. interface A set of methods that Java classes can implement. Internet The cooperatively run, globally distributed collection of computer networks that exchange information using the TCP/IP protocol suite. introspection The mechanism that exposes the functionality of a component to the outside world. Java An object-oriented programming language for creating secure, distributed, platform-independent applications. Java-enabled browser A World Wide Web browser that can display Java applets. language-independent A term used to indicate that a piece of software can be developed in any programming language. link A connection between one hypertext document and another. LiveConnect A technology included with Netscape Navigator that provides a way of interconnecting different types of executable content. low-level events Events that correspond to a low-level input or visual interface interaction. Matrix The set of all networks that can exchange electronic mail either directly or through gateways--including the Internet, BITNET, FidoNet, UUCP, and commercial services such as America Online, CompuServe, Delphi, and Prodigy. This term was coined by John S. Quarterman in his book The Matrix (Digital Press, 1990). method A function that can perform operations on data. MIME (Multipurpose Internet Mail Extensions) A specification for multimedia document formats. Mosaic A graphical Web browser originally developed by the National Center for Supercomputing Applications (NCSA). It now includes a number of commercially licensed products. multicast event source An event source capable of generating events for retrieval by any number of listeners. native methods Class methods declared in a Java class but implemented in C. navigating The act of observing the content of the Web for some purpose. NCSA (National Center for Supercomputing Applications) Developers and distributors of NCSA Mosaic at the University of Illinois at Champaign-Urbana. Net An informal term for the Internet or a subset (or a superset) of the Matrix in context. For example, a computerized conference using e-mail may take place on a BITNET host that has an Internet gateway, thus making the conference available to anyone on either of these networks. In this case, the developer might say, "Our conference will be available on the Net." Although you may even consider discussion forums on commercial online services to be "on the Net," these forums are not accessible from the Internet. newsgroup Internet message bases that provide forums for exchanging ideas, information, and opinions. object A variable defined as being a particular class type. An object has the data and methods as specified in the class definition. object-oriented A term specifying that a piece of software is composed of objects, which are self-contained modules that contain both data and procedures that act on the data. OLE (Object Linking and Embedding) A COM-based technology developed by Microsoft that provides a wide range of services, including application automation, reusable controls, version management, standardized drag-and-drop, documents, object linking and embedding, and visual editing. OpenDoc An open, multiplatform, component software architecture heavily backed by Apple and IBM. overload (verb) To use the same name for several items in the same scope; Java methods can be overloaded. package (Java) A set of classes with a common high-level function declared with the `package` keyword. packet A set of data handled as a unit in data transmission. page A single file of HyperText Markup Language. parameter (HTML) A name and value pair identified by the `Name` and `Value` attributes of the `PARAM` element used inside an `APPLET` element. parameter list (Java) The set of values passed to a method. The definition of the method describes how these values are manipulated. parent class The originating class of a given subclass. persistence The means by which a component is stored to and retrieved from a nonvolatile location such as a hard disk. platform A term referring to a particular operating system and runtime environment, such as Windows 95 or Solaris. property A discrete, named attribute of a JavaBeans component that determines its appearance and behavior. property editor A user interface that enables the visual editing of a particular property type. property sheet A user interface containing property editors for all the exported properties of a JavaBeans component. protocol handler A program loaded into the user's HotJava browser that interprets a protocol. These protocols include standards such as HTTP, as well as programmer-defined protocols. reflection The process of studying a bean to determine information about its functionality and public facilities. RMI (Remote Method Invocation) The execution of methods on remote Java objects located on other Java virtual machines--and sometimes on different hosts. robot A term for software programs that automatically explore the Web for a variety of purposes. Robots that collect resources for later database queries by users are sometimes called spiders. scope The program segment in which a reference to a variable is valid. semantic events Events that correspond to high-level visual interface actions based on the semantics of a bean. serialization The process of storing or retrieving information through a standard protocol. server A software application that provides information or services based on requests from client programs. setter method An accessor method that writes, or sets, the value of a property. SGML (Standard Generalized Markup Language) A standard for defining markup languages; HTML is an instance of SGML. (See `http://www.sgmlopen.org/`.) site The file section of a computer on which Web documents (or other documents served in another protocol) reside--for example, a Web site, a Gopher site, or an FTP site. software component A piece of software isolated into a discrete, easily reusable structure. Solaris Sun Microsystem's software platform for networked applications. Solaris includes the operating system, SunOS. Sparc (Scalable Processor ARChitecture) A microprocessor architecture based on very efficient handling of a small set of instructions. (See `http://www.sparc.com/`.) spider A software program that traverses the Web to collect information about resources for later queries by users who want to find resources. Major species of active spiders include Lycos and WebCrawler. surfing The act of navigating the Web, typically using techniques for rapidly traversing content, to find subjectively valuable resources. tag The code used to make up part of an HTML element. For example, the `TITLE` element has a start tag, `<TITLE>`, and an end tag, `</TITLE>`. TCP/IP (Transmission Control Protocol/Internet Protocol) The set of protocols used for network communication on the Internet. unicast event source An event source capable of generating events for retrieval by only one listener. Unicode A 16-bit character set that supports many world languages. URL (Uniform Resource Locator) The scheme for addressing on the Web. A URL identifies a resource on the Web. Usenet A system for disseminating asynchronous text discussion among cooperating computer hosts. The Usenet discussion space is divided into newsgroups, each concerned with a particular topic or subtopic. versioning The inevitable tendency for an object to evolve over time and gain new functionality. virtual machine The hypothetical microprocessor on which Java bytecodes execute. visual component A type of software component that has a visual representation requiring physical space on the display surface of a parent application. VRML (Virtual Reality Modeling Language) A specification for three-dimensional rendering used in conjunction with Web browsers. web A set of hypertext pages that are considered a single work. Typically, a single web is created by one author or cooperating authors and is deployed on a single server with links to other servers--that is, it is a subset of the Web. Web (World Wide Web) A hypertext information and communication system popularly used on the Internet computer network with data communications operating according to a client/server model. Web clients (browsers) can access multiprotocol and hypermedia information using an addressing scheme. Web server Software that provides services to Web clients. white paper A technical document outlining the goals of a new technology. wizard A user interface that uses multiple-step questionnaires to gather information from the user. WWW The World Wide Web. X X Window System. A windowing system that supports graphical user interfaces to applications. See also: Sun's Java Glossary `http://www.javasoft.com/javacontest/java-P1/project_files/faq/glossary.html`
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