Index | A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
abstract class: | a class that cannot have direct instances but whose descendents can have instances; a class that has declared one or more methods for which it does not provide definitions (i.e. abstract methods) |
abstract data type (ADT): | a data declaration packaged together with the functions that operate on it |
abstraction: | a mental facility that permits humans to view real-world problems with varying degrees of detail depending on the current context of the problem; the process of focusing on the essential, inherent aspects of an entity and ignoring its accidental properties; the selective examination of certain aspects of a problem |
absolute positioning: | using pixel coordinates to position GUI components |
access transparency: | a type of transparency that enables local and remote information objects to be accessed using identical operations |
action: | an instantaneous operation. Actions are associated with events and are usually formal in nature. |
active rendering: | a technique often used in animation where an application manages its own visual updates rather than relying on the operating system's rendering thread |
activity: | an operation that takes time to complete. Activities are associated with states and represent real-world accomplishments. |
activity diagram: | a UML diagram that models the activity (workflow) of a portion of a software system |
actor object: | an active object that drives a data flow graph by producing or consuming values. |
adapter class: | a class in the java.awt.event package that provides empty implementations of event listener methods so that the programmer can write code for only relavant events |
address space: | a collection of ranges of virtual memory locations with specific memory access rights |
ADT: | See abstract data type |
aggregation: | a tightly coupled form of association, between a whole and its parts, in which the whole is composed of the parts; see also compositioni |
algorithm: | a finite sequence of unambiguous instructions which,
when given the required input, produces the correct
output and then stops; a procedure for solving a problem in terms of the steps to be taken and the order in which the steps are to be carried out |
ALU: | Arithmetic/Logic Unit -- the part of the CPU responsible for performing arithmetic and Boolean operations |
analysis: | a stage in the development cycle in which a real-world problem is examined to understand its requirements without planning the implementation |
anonymous class: | a local class that is declared and instantiated in a single statement, often as a parameter to a method |
API: | Application Programming Interface -- the interface used by a program to access various services on the computer |
applet: | a Java program that runs in a web browser or other applet container |
architecture: | the overall structure of a system, including its partitioning into subsystems and their allocation to tasks and processors |
array: | a homogeneous collection of data items stored by a sequential ordinal index |
ASCII: | the American Standard Code for Information Interchange -- an encoding standard for text and control characters. ASCII is a subset of Unicode. |
assignment: | an operation that places a value in a variable |
association: | a relationship between objects and classes that describes a group of links with common structure and common semantics |
asynchronous communication: | communication in which the sending process can proceed as soon as the message has been sent out to a buffer |
at-least-once call semantics: | RPC semantics in which a caller sends a request message several times until a reply is received |
at-most-once call semantics: | RPC semantics in which duplicate messages are filtered out and replies are retransmitted without re-executing operations so that the remote procedure is executed once or not at all |
atomic multicast: | a multicast message that is either received by all intended recipients or none of them |
attribute: | a property of the objects in a class. Synonyms: Data member, member variable |
authentication server: | a server that provides a secure way for pairs of processes to obtain secret keys for secure encryption |
automatic variable: | a local variable |
auxiliary carry flag (AC): | a carry flag used by instructions that perform binary coded
decimal (BCD) arithmetic; the second bit in the PSW register
See carry flag |
availability: | a measure of a proportion of time that something can be used |