Glossary
This glossary describes terms used in this book and words used with other
than their everyday meaning. In some cases, a definition may not be the only
one applicable to a term, but it gives the particular sense in which the word
is used in this book.
If you do not find the term you are looking for, see the index or the IBM Dictionary of Computing, New York:. McGraw-Hill,
1994.
- Application Programming Interface (API)
- An Application
Programming Interface consists of the functions and variables that programmers
are allowed to use in their applications.
- asynchronous messaging
- A method of communicating
between programs in which the programs place messages on message queues. With
asynchronous messaging, the sending program proceeds with its own processing
without waiting for a reply to its message. Contrast with synchronous messaging.
- authenticator
- A program that checks that verifies
the senders and receivers of messages.
- bridge
- An WebSphere MQ Everyplace object that allows messages to
flow between WebSphere MQ Everyplace and other messaging systems, including WebSphere MQ.
- channel
- See dynamic channel, client/server channel, peer channel, and MQI
channel.
- channel manager
- An WebSphere MQ Everyplace object that supports logical
multiple concurrent communication pipes between end points.
- class
- A class is an encapsulated collection of
data and methods to operate on the data. A class may be instantiated to produce
an object that is an instance of the class.
- client
- (1)In WebSphere MQ Everyplace, a client is WebSphere MQ Everyplace code running
without a channel manager or channel listener. Contrast with server (1). (2)In WebSphere MQ, a client is a run-time component that provides
access to queuing services on a server for local user applications.
- client/server channel
- An WebSphere MQ Everyplace a unidirectional
channel between a client and a server that can only be established from
the client side. Contrast with peer channel.
- compressor
- A program that compacts a message to
reduce the volume of data to be transmitted.
- cryptor
- A program that encrypts a message to provide
security during transmission.
- device
- A small portable machine running WebSphere MQ Everyplace as
a client. Contrast with server(1).
- dynamic channel
- This is a name given to WebSphere MQ Everyplace channels
that connect clients and servers to enable the transfer of messages. They
are called dynamic because they are created on demand.
See client/server and peer channels. Contrast withMQI channel.
- encapsulation
- Encapsulation is an object-oriented
programming technique that makes an object's data private or protected and
allows programmers to access and manipulate the data only through method
calls.
- gateway
- An WebSphere MQ Everyplace gateway is a computer running
the WebSphere MQ Everyplace WebSphere MQ bridge code.
- Hypertext Markup Language (HTML)
- A language used
to define information that is to be displayed on the World Wide Web.
- instance
- An instance is an object. When a class
is instantiated to produce an object, we say that the object is an instance
of the class.
- interface
- An interface is a class that contains
only abstract methods and no instance variables. An interface provides
a common set of methods that can be implemented by subclasses of a number
of different classes.
- Internet
- The Internet is a cooperative public network
of shared information. Physically, the Internet uses a subset of the total
resources of all the currently existing public telecommunication networks.
Technically, what distinguishes the Internet as a cooperative public network
is its use of a set of protocols called TCP/IP (Transport Control Protocol/Internet
Protocol).
- Java Developers Kit (JDK)
- A package of software
distributed by Sun Microsystems for Java developers. It includes the Java
interpreter, Java classes and Java development tools: compiler, debugger,
disassembler, appletviewer, stub file generator, and documentation generator.
- Java Naming and Directory Service (JNDI)
- An API
specified in the Java programming language. It provides naming and directory
functions to applications written in the Java programming language.
- Lightweight Directory Access Protocol (LDAP)
- LDAP
is a client-server protocol for accessing a directory service.
- Local area network (LAN)
- A computer
network located on a user's premises within a limited geographical area.
- message
- In message queuing applications, a message
is a communication sent between programs.
- message queue
- See queue
- message queuing
- A programming technique in which
each program within an application communicates with the other programs by
putting messages on queues.
- method
- Method is the object-oriented programming
term for a function or procedure.
- MQI channel
- An MQI channel connects a WebSphere MQ client
to a queue manager on a server system and transfers MQI calls and responses
in a bidirectional manner. MQI channels must be explicitly created. Contrast
with dynamic channels.
- WebSphere MQ
- WebSphere MQ is a family of IBM licensed programs
that provide message queuing services.
- object
- (1) In Java, an object is an instance of
a class. A class models a group of things; an object models a particular
member of that group. (2) In WebSphere MQ, an object is a queue manager, a queue,
or a channel.
- package
- A package in Java is a way of giving a
piece of Java code access to a specific set of classes. Java code that is
part of a particular package has access to all the classes in the package
and to all non-private methods and fields in the classes.
- peer channel
- A bidirectional WebSphere MQ Everyplace channel, normally
used between clients. The connection can be established from either end.
- personal digital addistant (PDA)
- A pocket sized
personal computer.
- private
- A private field is not visible outside
its own class.
- protected
- A protected field is visible only within
its own class, within a subclass, or within packages of which the class is
a part
- public
- A public class or interface is visible everywhere.
A public method or variable is visible everywhere that its class is visible
- queue
- A queue is a WebSphere MQ object. Message queueing
applications can put messages on, and get messages from, a queue
- queue manager
- A queue manager is a system program
the provides message queuing services to applications.
- server
- (1) An WebSphere MQ Everyplace server is WebSphere MQ Everyplace code with
an WebSphere MQ Everyplace channel manager, and WebSphere MQ Everyplace channel listener, configured. This provides
the ability to receive from multiple devices and servers concurrently. Contrast
with client (1). (2)A computer running WebSphere MQ Everyplace server
code. Contrast with device. (3) A WebSphere MQ server is
a queue manager that provides message queuing services to client applications
running on a remote workstation. (4) More generally, a server is a program
that responds to requests for information in the particular two-program information
flow model of client/server, or the computer on which a server program runs.
- servlet
- A Java program which is designed to run
only on a web server.
- subclass
- A subclass is a class that extends another.
The subclass inherits the public and protected methods and variables of
its superclass.
- superclass
- A superclass is a class that is extended
by some other class. The superclass's public and protected methods and variables
are available to the subclass.
- synchronous messaging
- A method of communicating
between programs in which programs place messages on message queues. With
synchronous messaging, the sending program waits for a reply to its message
before resuming its own processing . Contrast with asynchronous
messaging.
- Transmission Control Protocol/Internet Protocol (TCP/IP)
- A set of communication protocols that support peer-to-peer connectivity
functions for both local and wide area networks.
- Web
- See World Wide Web.
- Web browser
- A program that formats and displays
information that is distributed on the World Wide Web.
- World Wide Web (Web)
- The World Wide Web is an Internet
service, based on a common set of protocols, which allows a particularly configured
server computer to distribute documents across the Internet in a standard
way.