markt's Java Glossary

A

• abstract - an abstract method is a promise that all non-abstract subclasses implement such a method
• Ada 95 - a language with a front-end to Java bytecodes (see Intermetrics)
• Adobe - a company that licensed Java from Sun (?)
• alpha - an old version of Java the language and the AWT. Hotjava has still not been upgraded from alpha to beta. The rest of the world uses beta Java. Obsolete
• Animator - an applet class to display a series of graphics frames.
• array - outside of classes, Java's only compound data-structure. Dynamically sized, there exists a class of array for each primitive type and every class, including array classes
• Arthur van Hoff - a principal aauthor of the AWT and Hotjava - often contributes to comp.lang.java
• app - the unnested HTML tag for alpha Java applets. Obsolete
• applet - a small Java program designed to be embedded in a page of HTML for client-side execution. A class and a calling convention exists for this AWT-reliant notion.
• applet - nested HTML tag for beta+ Java applets.
• AWT - A?? Window Toolkit - the standard GUI for Java from Sun. classes exist in the package java.awt

B

• beta - the current (Jan 96) version of Java the language and the AWT. Not compatible with alpha and the current version of the Hotjava browser.
• Blackdown - a site with Linux Java porting information and distribution
• bounds-check - the act of ensuring that an array index is not outside the bounds of the array before allowing indexing of the array. In Java an exception (java.lang.ArrayIndexOutOfBounds) is guaranteed to be thrown if an out-of-bounds index is used.
• Borland - a company that has licensed Java from Sun
• browser (WWW browser, Web-browser) - a program to download remote documents using HTTP, which potentially includes Java class files. So far only Sun's Hotjava (alpha) and Netscape Navigator 2.0b3+ (beta) support Java applets, TTBOMK.
• byte-codes - Java byte-codes are a fairly abstract and machine-independent representation of operations on a virtual stack machine. The code of Java methods in .class files is represented as a sequence of these byte-code instructions. The codes range from low level arithmetic and control-flow to higher level method-invocation and object allocation. There is sufficient type-information in the byte-codes to infer or disprove Java type-safety constraints.

C

• Cafe' - a Java IDE for the PC from Symantec, a.k.a. Espresso
• Cafebabe - an alternative name for j2c, a prototype and incomplete publicly available compiler from Java to C
• 0xCAFEBABE - the hex "magic number" for .class files. Someone at Sun thought it was a cute idea...
• class - the fundamental object type in Java, a collection of instance variables, static (class) variables and methods. The single-inheritance model is followed.
• Class - the meta-class in Java, all classes are instances of this class, full name java.lang.Class
• class-loading - the process of loading a .class file into the Java runtime system and resolving its references and verifying its security
• codebase - a tag inside the HTML tag applet for specifying the source of remote .class files
• compiler - in the Java world a program to turn Java source into bytecodes. The standard java compiler is javac. Also see native and JIT
• comp.lang.java - The main Java newsgroup. Very overcrowded and low s/n ratio. Note this is not the name of a class in the java.lang package!
• contest - Sun currently have a Java applet contest
• Cosmo - SGI's licensed proprietry Java technology, including a port. See also MIPS.

D

• DigitalEspresso - A summary service for Java news, updated weekly - reading this can save trawling a lot of messages in comp.lang.java
• Digitalfocus A site purporting to be a repository of Java development goodies and resources.
• DSTC - Distributed Systems Technology Centre, Australia, authors of a Java programming environment called "Espresso"

E

• Espresso - One of a number of software packages confusingly sharing a name:
  • Espresso Grinder (see below)
  • Espresso from DSTC, a programming environment
  • Espresso, now called "Cafe", Symantec's Java IDE.
  • Espresso an Ada 95 front-end from Intermetrics
  • DigitalEspresso (see above)
• Espresso Grinder - an alternative publicly available plug-in replacement javac from the University of Karlsruhe.
• exceptions - a means of transfering control to the innermost method prepared to handle an exception of its class. All exceptions must inherit from java.lang.Throwable and the try, catch and finally syntax is available in Java for defining handlers and handled regions

F

• final - Java keyword indicating that a variable, method or class cannot be further defined or overridden or subclassed
• Fujitsu - a hardware company that has licensed Java from Sun

G

• garbage collection - the automatic reclamation of memory resources no longer referenced by the running application
• Gamelan - a large respository of Java applets and resources
• GC (see garbage collection)
• Guava - the posible FSF Java clone - nothing seems certain about this, but see guavac
• guavac - the FSF plug-in replacement for javac, but note that this one is written in C++ rather than Java.
• Guile The GNU portable virtual machine architecture, under construction and aimed at multilanguage and multi-interpreter working, based on a Lispy sort of heap (the name is a pun on "Scheme" I believe) and a C-compatible GC, and supposed to be acquiring a Java interpreter soon.

H

• hackjava - a site compiling details of security bugs and weaknesses in Sun's Java and Hotjava
• HORB - a Japanese distributed object computing language/system, built on top of Java, designed to replace CGI.
• Hotjava - Sun's extensible WWW browser built entirely in (alpha) Java

I

• IBM - a company that has licensed Java from Sun
• ICE - a Java package supporting VRML, part of DimensionX's Liquid Reality product
• inheritance - the definition of a class as an extension of an existing class and hence automatically inheriting the superclasses properties.
• instance - an object of a particular class, upon which the class's methods can be applied.
• interface - in Java an interface is a type representing the union of all classes that "implement" the set of methods listed in the interface definition. It is not a real class.
• Intermetrics - a company producing an Ada 95 systems, including a front-end to Java bytecodes
• interpreter - The Java interpreter (java) from Sun is a C program that executes Java bytecodes, and provides other runtime support

J

• j2c (see CafeBabe)
• java - the standard Sun java interpreter command, takes a class name and list of arguments.
• Java - An object-oriented language featuring single inheritence plus interfaces, garbage collection, dynamic exceptions, multi-threading with monitors, security controls, with a simplfied C++-like syntax. The standard implementation for Solaris, Windows 95 and Windows NT is publicly available from Sun microsystems, the creators of the language. Also the subject of this glossary
• javac - the standard Sun java compiler, itself implemented in Java. Very slow.
• JavaCup - either the Sun Java contest (see contest) or a Java parser generator
• JavaNotes (now DigitalEspresso)
• javap - the standard Sun .class file printer/disassembler.
• JavaScript - used to be known as LiveScript, a Web-browser scripting language, apparently based on Java, and available in Netscape
• Javasoft - a new company set up by Sun
• javaspec - the specification of the Java language, currently only available in PostScript format
• Java VM - The Java Virtual Machine, an architecture-neutralish abstract machine, with garbage collection, single inheritance, multi-threading and native-methods. The online documentation is also available as PostScript
• Javaside, now known as "Diva for Java", a Windows IDE for Java
• JDK - Java Developers Kit, the standard publicly-available Java implementation.
• JIT - just-in-time compilation, where Java byte-codes are incremental compiled to native code on demand

K

L

• LiveScript (see JavaScript)
• Lotus - a company that has licensed Java from Sun

M

• Macromedia - a company that has promised to support Java from Sun
• method - a named behaviour whose definition is a property of the class of the object involved, and can be overridden
• Metrowerks - a company that has licensed Java from Sun for its Mac/Power Mac multi-language programming environment. The code-name for this is "wired"
• Microsoft - a company that has signed a letter of agreement to license Java from Sun.
• MIPS - a publicly available Java port for the SGI/MIPS platform exists - it is not complete, but the compiler works.
• Mocha - BulletProof's Object DB engine
• monitor - a guard over an object to prevent more that one thread accessing it at a time unintentionally. Java programs use the synchronized keyword to say "get me the monitor for this object" to ensure single-threaded access. The methods wait and notify on Object allow for co-operating temporary relinquishing of a monitor.

N

• native - running on or compiled for the host (hardware) processor.
• native
• Natural Intelligence - a company producing Roaster a Java IDE for the Mac and Power Mac
• Nelson Yu - author on an online tutorial for the AWT
• Netscape - a company producing a WWW browser with beta Java support on many platforms. Netscape 2.0beta3 or later is required. To do this they licensed Java from Sun
• null - the Java denotation for a null pointer. Many Java operations detect such null pointers and throw a java.lang.NullPointerException

O

• Object The Java class from which all other classes derive. Full name java.lang.Object
• OSF - Open Software Foundation - have several projects on Java
• overloading - when several methods are identical in name, but distinquished by having differing combinations of argument types.
• overriding - when a method in a subclass takes over from one of the same name and shape in a superclass.

P

• package - a Java keyword for specifying the current package, or namespace.
• param - tag for use in the "applet" HTML tag, for suppling named parameter values to the applet.
• private - Java keyword to control access to variables methods and classes.
• protected - Java keyword to control access to variables methods and classes.
• public - Java keyword to specify unrestricted access to variables methods and classes.

Q

R

• Roaster Natural Intelligences Java IDE for Mac.

S

• security - Java is designed to allow secure implementation. For more information see the whitepaper
• Shockwave - multimedia playback technology for browsers from Macromedia
• Silicon Graphics - a company that has licences Java from Sun.
• static - a Java keyword denoting that a variable exists once in the class, or a method that is not closed over an instance of the defining class. Classes can have static initialization code, again denoted by this keyword
• Sun - Sun Microsystems, the creators and licensors of Java, a large workstation vendor...
• Symantec - a company that have produced Cafe - a Java IDE for Windows

T

• TeamJava - a site acting as repository for Java development resources.
• Thread - the Java class supporting threads. The native methods for this class implement a multi-threaded enviroment for Java code. Full name java.lang.Thread, also see monitors

U

V

• virtual method dispatch - the mechanism by which the most specific defined method for a particular instance is located
• virtual machine - an abstract platform for execution of code and encoding of data-structures. Usually, as in Java's case, designed to be independent from any particular processor design
• VM (see Java VM)
• vmspec - Sun's online specification of 1.0beta Java Virtual Machine.

W

• whitepaper - the Java whitepaper.
• wired - see Metrowerks

X

Y

Z

Last updated by markt@chaos.org.uk Wed 31 January 1996