A collection of graphical user interface (GUI) components that were implemented using
native-platform versions of the components. These components provide that subset of
functionality which is common to all native platforms. Largely supplanted by the Project
Swing component set. See also
A Java(TM) programming language keyword used in a class definition to specify that a
class is not to be instantiated, but rather inherited by other classes. An abstract class
can have abstract methods that are not implemented in the abstract class, but in
subclasses.
abstract class
A class that contains one or more
abstract methods
, and therefore can never be
instantiated. Abstract classes are defined so that other classes can extend them and make
them concrete by implementing the abstract methods.
abstract method
A method that has no implementation.
access control
The methods by which interactions with resources are limited to collections of users or
programs for the purpose of enforcing integrity, confidentiality, or availability
constraints.
ACID
The acronym for the four properties guaranteed by transactions: atomicity, consistency,
isolation, and durability.
activation
The process of transferring an enterprise bean from secondary storage to memory. (See
passivation.)
Application Programming Interface. The specification of how a programmer writing an
application accesses the behavior and state of classes and objects.
applet
A component that typically executes in a Web browser, but can execute in a variety of
other applications or devices that support the applet programming model.
Applet container
A container that includes support for the applet programming model.
appliances
Networked devices such as printers, Java(TM) technology-enabled terminals, and clients,
that are managed using applications built using the Java Management API (JMAPI).
Application Assembler
A person that combines components and modules into larger deployable application units.
application client
A first-tier client program that executes in its own Java Virtual Machine.
application client container
A container that supports application clients and provides a federated view of the J2EE
platform APIs.
application client module
A software unit that consists of one or more classes and an application client
deployment descriptor.
Application Component Provider
A vendor that provides the Java classes that implement components' methods, JSP page
definitions, and any required deployment descriptors.
APM
Application Programming Model. A programming model that defines how to use and combine
the features of the J2EE platform to create solutions for common application domains in
the enterprise.
argument
A data item specified in a method call. An argument can be a literal value, a variable,
or an expression.
array
A collection of data items, all of the same type, in which each item's position is
uniquely designated by an integer.
Refers to an operation that is never interrupted or left in an incomplete state under
any circumstance.
authentication
The process by which an entity proves to another entity that it is acting on behalf of a
specific identity. The J2EE platform requires three types of authentication: basic,
form-based, and mutual.
authorization
See access control.
authorization constraint
A set of security roles that are allowed access to the resources in a Web resource
collection.
When a Web server authenticates an entity with a user name and password obtained using
the Web client's built-in authentication mechanism.
Bean
A reusable software component. Beans can be combined to create an application.
bean-managed persistence
When the transfer of data between an entity bean instance's variables and the underlying
resource manager is managed by the entity bean.
bean-managed transaction
When an enterprise bean defines the boundaries of the transaction.
bean-managed transaction
When an enterprise bean defines the boundaries of the transaction.
binary operator
An operator that has two arguments.
bit
The smallest unit of information in a computer, with a value of either 0 or 1.
bitwise operator
An operator that manipulates the bits of one or more of its operands individually and in
parallel. Examples include the binary logical operators (&, |, ^), the binary shift
operators (<<, >>, >>>) and the unary one's complement operator (~).
block
In the Java(TM) programming language, any code between matching braces. Example: {
x = 1; }.
boolean
Refers to an expression or variable that can have only a true or false value. The
Java(TM) programming language provides the boolean type and the literal values true and
false.
bounding box
The smallest rectangle that encloses a geometric shape. For a Raster object, the
smallest rectangle that completely encloses all the defined pixels.
break
A Java(TM) programming language keyword used to resume program execution at the
statement immediately following the current statement. If followed by a label, the program
resumes execution at the labeled statement.
business logic
The code that implements the functionality of an application. In the Enterprise
JavaBeans model, this logic is implemented by the methods of an enterprise bean.
business method
A method of an enterprise bean that implements the business logic or rules of an
application.
byte
A sequence of eight bits. The Java(TM) programming language provides a corresponding byte
type.
bytecode
Machine-independent code generated by the Java(TM) compiler and executed by the Java
interpreter.
Methods in a component called by the container to notify the component of important
events in its life cycle.
caller
Same as caller principal.
caller principal
The principal that identifies the invoker of an enterprise bean method.
case
A Java(TM) programming language keyword that defines a group of statements to begin
executing if a value specified matches the value defined by a preceding "switch"
keyword.
casting
Explicit conversion from one data type to another.
catch
A Java(TM) programming language keyword used to declare a block of statements to be
executed in the event that a Java exception, or run time error, occurs in a preceding
"try" block.
char
A Java(TM) programming language keyword used to declare a variable of type character.
In the Java(TM) programming language, a type that defines the implementation of a
particular kind of object. A class definition defines instance and class variables and
methods, as well as specifying the interfaces the class implements and the immediate
superclass of the class. If the superclass is not explicitly specified, the superclass
will implicitly be Object.
A method that is invoked without reference to a particular object. Class methods affect
the class as a whole, not a particular instance of the class. Also called a
A classpath is an environmental variable which tells the Java(TM) virtual machine*
and Java technology-based applications (for example, the tools located in the JDK(TM)
1.1.X\bin directory) where to find the class libraries, including user-defined class
libraries.
A data item associated with a particular class as a whole--not with particular instances
of the class. Class variables are defined in class definitions. Also called a
In the client/server model of communcations, the client is a process that remotely
accesses resources of a compute server, such as compute power and large memory capacity.
codebase
Works together with the code attribute in the <APPLET>
tag to give a complete specification of where to find the main applet class file: code
specifies the name of the file, and codebase specifies the URL of the directory containing
the file.
comment
In a program, explanatory text that is ignored by the compiler. In programs written in
the Java(TM) programming language, comments are delimited using // or /*...*/.
commit
The point in a transaction when all updates to any resources involved in the transaction
are made permanent.
compilation unit
The smallest unit of source code that can be compiled. In the current implementation of
the Java(TM) platform, the compilation unit is a file.
A program to translate source code into code to be executed by a computer. The Java(TM)
compiler translates source code written in the Java programming language into bytecode for
the Java virtual machine*. See also
An application-level software unit supported by a container. Components are configurable
at deployment time. The J2EE platform defines four types of components: enterprise beans,
Web components, applets, and application clients.
component contract
The contract between a component and its container. The contract includes: life cycle
management of the component, a context interface that the instance uses to obtain various
information and services from its container, and a list of services that every container
must provide for its components.
component environment
A set of requirements defined by the Application Component Provider required to be
available to a J2EE component in its naming environment. The environment entries are
declaratively specified in the component's deployment descriptor. Each component names and
accesses its environment configuration values using the java:comp/env JNDI context. These
values can be objects a component is dependent on, such as a JDBC DataSource or a simple
value such as a tax rate.
compositing
The process of superimposing one image on another to create a single image.
connection
See resource manager connection.
connection factory
See resource manager connection factory.
connector
A standard extension mechanism for containers to provide connectivity to EISs. A
connector is specific to an EIS and consists of a resource adapter and application
development tools for EIS connectivity. The resource adapter is plugged in to a container
through its support for system level contracts defined in the connector architecture.
connector architecture
An architecture for integration of J2EE servers with EISs. There are two parts to this
architecture: a EIS vendor-provided resource adapter and a J2EE server that allows this
resource adapter to plug in. This architecture defines a set of contracts that a resource
adapter has to support to plug in to a J2EE server, for example, transactions, security,
resource management.
constructor
A pseudo-method that creates an object. In the Java(TM) programming language,
constructors are instance methods with the same name as their class. Constructors are
invoked using the new keyword.
const
This is a reserved Java(TM) programming language keyword. However, it is not used by
current versions of the Java programming language.
container
An entity that provides life cycle management, security, deployment, and runtime
services to components. Each type of container (EJB, Web, JSP, servlet, applet, and
application client) also provides component-specific services.
container-managed persistence
When transfer of data between an entity bean's variables and the underlying resource
manager is managed by the enterprise bean's container.
container-managed transaction
When an EJB container defines the boundaries of a transaction. An entity bean must use
container-managed transactions.
context attribute
An object bound into the context associated with a servlet.
continue
A Java(TM) programming language keyword used to resume program execution at the end of
the current loop. If followed by a label, "continue" resumes execution where the
label occurs.
conversational state
The field values of a session bean plus the transitive closure of the objects reachable
from the bean's fields. The transitive closure of a bean is defined in terms of the
serialization protocol for the Java programming language, that is, the fields that would
be stored by serializing the bean instance.
CORBA
Common Object Request Broker Architecture. A language independent, distributed object
model specified by the Object Management Group (OMG).
core class
A public class (or interface) that is a standard member of the Java(TM) Platform. The
intent is that the core classes for the Java platform, at minimum, are available on all
operating systems where the Java platform runs. A program written entirely in the Java
programming language relies only on core classes, meaning it can run anywhere. See also,
The required set of APIs in a Java platform edition which must be supported in any and
all compatible implementations.
create method
A method defined in the home interface and invoked by a client to create an enterprise
bean.
credentials
The information describing the security attributes of a principal. Credentials can be
acquired only through authentication or delegation.
critical section
A segment of code in which a thread uses resources (such as certain instance variables)
that can be used by other threads, but that must not be used by them at the same time.
CTS
Compatibility Test Suite. A suite of compatibility tests for verifying that a J2EE
product complies with the J2EE platform specification.
A statement that establishes an identifier and associates attributes with it, without
necessarily reserving its storage (for data) or providing the implementation (for
methods). See also
definition
.
default
A Java(TM) programming language keyword optionally used after all "case"
conditions in a "switch" statement. If all "case" conditions are not
matched by the value of the "switch" variable, the "default" keyword
will be executed.
definition
A declaration that reserves storage (for data) or provides implementation (for methods).
See also
declaration
.
delegation
An act whereby one principal authorizes another principal to use its identity or
privileges with some restrictions.
Deployer
A person who installs modules and J2EE applications into an operational environment.
deployment
The process whereby software is installed into an operational environment.
deployment descriptor
An XML file provided with each module and application that describes how they should be
deployed. The deployment descriptor directs a deployment tool to deploy a module or
application with specific container options and describes specific configuration
requirements that a deployer must resolve.
deprecation
Refers to a class, interface, constructor, method or field that is no longer
recommended, and may cease to exist in a future version.
An application made up of distinct components running in separate runtime environments,
usually on different platforms connected via a network. Typical distributed applications
are two-tier (client/server), three-tier (client/middleware/server), and n-tier
(client/multiple middleware/multiple servers).
do
A Java(TM) programming language keyword used to declare a loop that will iterate a block
of statements. The loop`s exit condition can be specified with the "while"
keyword.
DOM
Document Object Model. A tree of objects with interfaces for traversing the tree and
writing an XML version of it, as defined by the W3C specification.
double
A Java(TM) programming language keyword used to define a variable of type double.
A container that implements the EJB component contract of the J2EE architecture. This
contract specifies a runtime environment for enterprise beans that includes security,
concurrency, life cycle management, transaction, deployment, and other services. An EJB
container is provided by an EJB or J2EE server.
EJB Container Provider
A vendor that supplies an EJB container.
EJB context
An object that allows an enterprise bean to invoke services provided by the container
and to obtain the information about the caller of a client-invoked method.
EJB home object
An object that provides the life cycle operations (create, remove, find) for an
enterprise bean. The class for the EJB home object is generated by the container's
deployment tools. The EJB home object implements the enterprise bean's home interface. The
client references an EJB home object to perform life cycle operations on an EJB object.
The client uses JNDI to locate an EJB home object.
EJB .jar file
A JAR archive that contains an EJB module.
EJB module
A software unit that consists of one or more enterprise beans and an EJB deployment
descriptor.
EJB object
An object whose class implements the enterprise bean's remote interface. A client never
references an enterprise bean instance directly; a client always references an EJB object.
The class of an EJB object is generated by the container's deployment tools.
EJB server
Software that provides services to an EJB container. For example, an EJB container
typically relies on a transaction manager that is part of the EJB server to perform the
two-phase commit across all the participating resource managers. The J2EE architecture
assumes that an EJB container is hosted by an EJB server from the same vendor, so does not
specify the contract between these two entities. An EJB server may host one or more EJB
containers.
EJB Server Provider
A vendor that supplies the EJB server.
EIS resource
An entity that provides EIS-specific functionality to its clients. Examples are: a
record or set of records in a database system, a business object in an ERP system, and a
transaction program in a transaction processing system.
else
A Java(TM) programming language keyword used to execute a block of statements in the
case that the test condition with the "if" keyword evaluates to false.
EmbeddedJava(TM) Technology
The availability of Sun's Java 2 Platform, Micro Edition technology under a restrictive
license agreement that allows a licensee to leverage certain Java technologies to create
and deploy a closed-box application that exposes no APIs.
encapsulation
The localization of knowledge within a module. Because objects encapsulate data and
implementation, the user of an object can view the object as a black box that provides
services. Instance variables and methods can be added, deleted, or changed, but as long as
the services provided by the object remain the same, code that uses the object can
continue to use it without being rewritten. See also
A component that implements a business task or business entity; either an entity beans
or a session bean.
Enterprise Information System (EIS)
The applications that comprise an enterprise's existing system for handling company-wide
information. These applications provide an information infrastructure for an enterprise.
An EIS offers a well defined set of services to its clients. These services are exposed to
clients as local and/or remote interfaces. Examples of EISs include: an ERP system, a
mainframe transaction processing system, and a legacy database system.
Enterprise Bean Provider
An application programmer who produces enterprise bean classes, remote and home
interfaces, and deployment descriptor files, and packages them in an EJB .jar file.
Enterprise JavaBeans(TM) (EJB)
A component architecture for the development and deployment of object-oriented,
distributed, enterprise-level applications. Applications written using the Enterprise
JavaBeans architecture are scalable, transactional, and multi-user and secure.
entity bean
An enterprise bean that represents persistent data maintained in a database. An entity
bean can manage its own persistence or it can delegate this function to its container. An
entity bean is identified by a primary key. If the container in which an entity bean is
hosted crashes, the entity bean, its primary key, and any remote references survive the
crash.
ebXML
ebXML builds upon the XML (Extensive Markup Language) standard to deliver a modular
suite of specifications that enables enterprises of any size and in any geographical
location to conduct business over the Internet. It provides companies and organizations
with a standard method to exchange business messages, conduct trading relationships,
communicate data in common terms and define and register business processes.
exception
An event during program execution that prevents the program from continuing normally;
generally, an error. The Java(TM) programming language supports exceptions with the try,
catch, and throw keywords. See also
exception handler
.
exception handler
A block of code that reacts to a specific type of
exception
. If the exception
is for an error that the program can recover from, the program can resume executing after
the exception handler has executed.
executable content
An application that runs from within an HTML file. See also
Class X extends class Y to add functionality, either by adding fields or methods to
class Y, or by overriding methods of class Y. An interface extends another interface by
adding methods. Class X is said to be a subclass of class Y. See also
A data member of a class. Unless specified otherwise, a field is not static.
final
A Java(TM) programming language keyword. You define an entity once and cannot change it
or derive from it later. More specifically: a final class cannot be subclassed, a final
method cannot be overridden and a final variable cannot change from its initialized value.
finally
A Java(TM) programming language keyword that executes a block of statements regardless
of whether a Java Exception, or run time error, occurred in a block defined previously by
the "try" keyword.
float
A Java(TM) programming language keyword used to define a floating point number variable.
for
A Java(TM) programming language keyword used to declare a loop that reiterates
statements. The programmer can specify the statements to be executed, exit conditions, and
initialization variables for the loop.
form-based authentication
When a Web container provides an application-specific form for logging in.
FTP
The basic Internet File Transfer Protocol. FTP, which is based on TCP/IP, enables the
fetching and storing of files between hosts on the Internet. See also
The automatic detection and freeing of memory that is no longer in use. The Java(TM)
runtime system performs garbage collection so that programmers never explicitly free
objects.
goto
This is a reserved Java(TM) programming language keyword. However, it is not used by
current versions of the Java programming language.
group
A collection of principals within a given security policy domain.
GUI
Graphical User Interface. Refers to the techniques involved in using graphics, along
with a keyboard and a mouse, to provide an easy-to-use interface to some program.
An object that identifies an enterprise bean. A client may serialize the handle, and
then later deserialize it to obtain a reference to the enterprise bean.
The numbering system that uses 16 as its base. The marks 0-9 and a-f (or equivalently
A-F) represent the digits 0 through 15. In programs written in the Java(TM) programming
language, hexadecimal numbers must be preceded with 0x. See also
A classification of relationships in which each item except the top one (known as the
root) is a specialized form of the item above it. Each item can have one or more items
below it in the hierarchy. In the Java(TM) class hierarchy, the root is the Object
class.
home interface
One of two interfaces for an enterprise bean. The home interface defines zero or more
methods for creating and removing an enterprise bean. For session beans, the home
interface defines create and remove methods, while for entity beans, the home interface
defines create, finder, and remove methods.
home handle
An object that can be used to obtain a reference of the home interface. A home handle
can be serialized and written to stable storage and deserialized to obtain the reference.
HotJava(TM) Browser
An easily customizable Web browser developed by Sun Microsystems, which is written in
the Java(TM) programming language.
HTML
HyperText Markup Language. This is a file format, based on SGML, for hypertext documents
on the Internet. It is very simple and allows for the embedding of images, sounds, video
streams, form fields and simple text formatting. References to other objects are embedded
using URLs.
HTTP
HyperText Transfer Protocol. The Internet protocol, based on TCP/IP, used to fetch
hypertext objects from remote hosts. See also
Interface Definition Language. APIs written in the Java(TM) programming language that
provide standards-based interoperability and connectivity with CORBA (Common Object
Request Broker Architecture).
identifier
The name of an item in a program written in the Java(TM) programming language.
IIOP
Internet Inter-ORB Protocol. A protocol used for communication between CORBA object
request brokers.
if
A Java(TM) programming language keyword used to conduct a conditional test and execute a
block of statements if the test evaluates to true.
impersonation
An act whereby one entity assumes the identity and privileges of another entity without
restrictions and without any indication visible to the recipients of the impersonator's
calls that delegation has taken place. Impersonation is a case of simple delegation.
implements
A Java(TM) programming language keyword optionally included in the class declaration to
specify any interfaces that are implemented by the current class.
import
A Java(TM) programming language keyword used at the beginning of a source file that can
specify classes or entire packages to be referred to later without including their package
names in the reference.
inheritance
The concept of classes automatically containing the variables and methods defined in
their
A parameter that initializes the context associated with a servlet.
instance
An object of a particular class. In programs written in the Java(TM) programming
language, an instance of a class is created using the new operator followed
by the class name.
Any item of data that is associated with a particular object. Each instance of a class
has its own copy of the instance variables defined in the class. Also called a
A two-argument Java(TM) programming language keyword that tests whether the run-time
type of its first argument is assignment compatible with its second argument.
int
A Java(TM) programming language keyword used to define a variable of type integer.
interface
A Java(TM) programming language keyword used to define a collection of method
definitions and constant values. It can later be implemented by classes that define this
interface with the "implements" keyword.
An enormous network consisting of literally millions of hosts from many organizations
and countries around the world. It is physically put together from many smaller networks
and data travels by a common set of protocols.
Internet Protocol. The basic protocol of the Internet. It enables the unreliable
delivery of individual packets from one host to another. It makes no guarantees about
whether or not the packet will be delivered, how long it will take, or if multiple packets
will arrive in the order they were sent. Protocols built on top of this add the notions of
connection and reliability. See also
A module that alternately decodes and executes every statement in some body of code. The
Java(TM) interpreter decodes and executes bytecode for the Java virtual machine*.
See also
Any deployable unit of J2EE functionality. This can be a single module or a group of
modules packaged into an .ear file with a J2EE application deployment descriptor. J2EE
applications are typically engineered to be distributed across multiple computing tiers.
J2EE product
An implementation that conforms to the J2EE platform specification.
J2EE Product Provider
A vendor that supplies a J2EE product.
J2EE server
The runtime portion of a J2EE product. A J2EE server provides Web and/or EJB containers.
JAE
Java(TM) Application Environment. The source code release of the Java Development Kit
(JDK(TM)) software.
JAIN
See: Java APIs for Integrated Networks(TM) (JAIN)
JAR Files (.jar)
Java ARchive. A file format used for aggregating many files into one.
JAR file format
JAR (Java Archive) is a platform-independent file format that aggregates many files into
one. Multiple applets written in the Java(TM) programming language, and their requisite
components (.class files, images, sounds and other resource files) can be bundled in a JAR
file and subsequently downloaded to a browser in a single HTTP transaction. It also
supports file compression and digital signatures.
Java(TM)
is Sun's trademark for a set of technologies for creating and safely running software
programs in both stand-alone and networked environments.
Java Application Environment (JAE)
The source code release of the Java Development Kit (JDK(TM)) software.
Java APIs for Integrated Networks(TM) (JAIN)
enables the rapid development of Next Generation telecom products and services on the
Java platform.
Java(TM) 2 Platform, Standard Edition (J2SE platform)
An environment for developing and deploying enterprise applications. The J2EE platform
consists of a set of services, application programming interfaces (APIs), and protocols
that provide the functionality for developing multi-tiered, Web-based applications.
Java(TM) 2 SDK, Enterprise Edition
Sun's implementation of the J2EE platform. This implementation provides an operational
definition of the J2EE platform.
JavaBeans(TM)
A portable, platform-independent reusable component model.
Java Blend(TM)
A product that enables developers to simplify database application development by
mapping database records to objects in the Java(TM) programming language (Java objects)
and Java objects to databases.
Java Card(TM) API
An ISO 7816-4 compliant application environment focused on smart cards.
JavaCheck(TM)
A tool for checking compliance of applications and applets to a specification.
JavaChip(TM)
Sun's processor, which executes bytecode for the Java(TM) virtual machine*
natively. With a JavaChip processor, bytecode bypasses the virtual machine or just-in-time
compiler stage to go directly to the processor.
Java(TM) Compatibility Kit (JCK)
A test suite, a set of tools, and other requirements used to certify a Java platform
implementation conformant both to the applicable Java platform specifications and to Java
Software reference implementations.
Java Database Connectivity (JDBC(TM))
An industry standard for database-independent connectivity between the Java(TM) platform
and a wide range of databases. The JDBC(TM) provides a call-level API for SQL-based
database access.
Java Developer Connection(SM)
A service designed for individual developers, providing online training, product
discounts, feature articles, bug information, and early access capabilities.
Java Development Kit (JDK(TM))
A software development environment for writing applets and applications in the Java
programming language.
Java(TM) Electronic Commerce Framework
A structured architecture for the development of electronic commerce applications in the
Java(TM) programming language.
Java(TM) Enterprise API
This API makes it easy to create large-scale commercial and database applications that
can share multimedia data with other applications within an organization or across the
Internet. Four APIs have been designed within the Java(TM) Enterprise API family.
Java(TM) Foundation Classes (JFC)
An extension that adds graphical user interface class libraries to the Abstract
Windowing Toolkit (AWT).
Java(TM) IDL
A technology that provides CORBA interoperability and connectivity capabilities for the
J2EE platform. These capabilities enable J2EE applications to invoke operations on remote
network services using the OMG IDL and IIOP.
Java(TM) Interface Definition Language (IDL)
APIs written in the Java programming language that provide standards-based
interoperability and connectivity with CORBA (Common Object Request Broker Architecture).
JavaMail(TM)
An API for sending and receiving email.
Java(TM) Media APIs
A set of APIs that support the integration of audio and video clips, 2D fonts, graphics,
and images as well as 3D models and telephony.
Java(TM) Media Framework
The core framework supports clocks for synchronizing between different media (e.g.,
audio and video output). The standard extension framework allows users to do full audio
and video streaming.
Java(TM) Message Service (JMS)
An API for using enterprise messaging systems such as IBM MQ Series, TIBCO Rendezvous,
and so on.
Java Naming and Directory Interface(TM) (JNDI)
A set of APIs that assists with the interfacing to multiple naming and directory
services.
JavaOS(TM)
An Java(TM) technology-based operating system that is optimized to run on a variety of
computing and consumer platforms. The JavaOS(TM) operating environment provides a runtime
specifically tuned to run applications written in the Java programming language directly
on hardware platforms without requiring a host operating system.
JavaPlan(TM)
An object-oriented design and diagramming tool written in the Java(TM) programming
language.
Java(TM) Platform
Consists of the Java language for writing programs; a set of APIs, class libraries, and
other programs used in developing, compiling, and error-checking programs; and a Java
virtual machine which loads and executes the class files.
In addition, the Java platform is subject to a set of compatibility requirements to ensure
consistent and compatible implementations. Implementations that meet the compatibility
requirements may qualify for Sun's targeted compatibility brands.
Java 2 is the current generation of the Java Platform.
Java(TM) Platform Editions
A Java platform "edition" is a definitive and agreed-upon version of the Java
platform that provides the functionality needed over a broad market segment.
An edition is comprised of two kinds of API sets: (i) "core packages," which are
essential to all implementations of a given platform edition, and (ii) "optional
packages," which are available for a given platform edition and which may be
supported in a compatible implementation.
There are 3 distinct editions of the Java Platform:
* Java 2 Platform, Enterprise Edition:
The edition of the Java platform that is targeted at enterprises to enable development,
deployment, and management of multi-tier server-centric applications.
* Java 2 Platform, Standard Edition:
The edition of the Java platform that enables development, deployment, and management of
cross-platform, general-purpose applications.
* Java 2 Platform, Micro Edition:
The edition of the Java platform that is targeted at small, standalone or connectable
consumer and embedded devices to enable development, deployment, and management of
applications that can scale from smart cards through mobile devices and set-top boxes to
conventional computing devices.
A distributed object model for Java(TM) program to Java program, in which the methods of
remote objects written in the Java programming language can be invoked from other Java
virtual machines*, possibly on different hosts.
Java(TM) Runtime Environment (JRE)
A subset of the Java Development Kit (JDK(TM)) for end-users and developers who want to
redistribute the runtime environment alone. The Java runtime environment consists of the
Java virtual machine*, the Java core classes, and supporting files.
JavaSafe(TM)
A tool for tracking and managing source file changes, written in the Java(TM)
programming language.
JavaScript(TM)
A Web scripting language that is used in both browsers and Web servers. Like all
scripting languages, it is used primarily to tie other components together or to accept
user input.
JavaServer Pages(TM) (JSP)
An extensible Web technology that uses template data, custom elements, scripting
languages, and server-side Java objects to return dynamic content to a client. Typically
the template data is HTML or XML elements, and in many cases the client is a Web browser.
JAX
JAX collectively refers to a set of Java-based APIs for handling various operations
involving data defined through XML. This includes operations such XML parsing,
registration in ebXML or UDDI repositories, inter-application messaging, data binding, and
remote procedure calls.
JSP action
A JSP element that can act on implicit objects and other server-side objects or can
define new scripting variables. Actions follow the XML syntax for elements with a start
tag, a body and an end tag; if the body is empty it can also use the empty tag syntax. The
tag must use a prefix.
JSP action, standard
An action that is defined in the JSP specification and is always available to a JSP file
without being imported.
JSP action, custom
An action described in a portable manner by a tag library descriptor and a collection of
Java classes and imported into a JSP page by a taglib directive.
JSP application
A stand-alone Web application written using the JavaServer Pages technology, including
JSP files, servlets, HTML files, images, applets, and JavaBeans components.
JSP container
A container that provides the same services as a servlet container and an engine that
interprets and processes JSP pages into a servlet.
JSP container, distributed
A JSP container that can run a Web application that is tagged as distributable and that
executes across multiple Java virtual machines running on the same host or on different
hosts.
JSP declaration
A JSP scripting element that declares methods, variables, or both in a JSP file.
JSP directive
A JSP element that gives an instruction to the JSP container and is interpreted at
translation time.
JSP element
A portion of a JSP page that is recognized by a JSP translator. An element can be a
directive, an action, or a scripting element.
JSP expression
A scripting element that contains a valid scripting language expression that is
evaluated, converted to a String, and placed into the implicit out object.
JSP file
A file named with a .jsp extension that a developer authors using standard HTML tags,
core JSP tags, custom JSP tags, and scripting language statements in order to display
dynamic pages in a Web browser.
JSP page
A text-based document using fixed template data and JSP elements that describes how to
process a request to create a response.
JSP scripting element
A JSP declaration, scriptlet, or expression, whose tag syntax is defined by the JSP
specification, and whose content is written according to the scripting language used in
the JSP page. The JSP specification describes the syntax and semantics for the case where
the language page attribute is "java".
JSP scriptlet
A JSP scripting element containing any code fragment that is valid in the scripting
language used in the JSP page. The JSP specification describes what is a valid scriptlet
for the case where the language page attribute is "java".
JSP tag
A piece of text between a left angle bracket and a right angle bracket that is used in a
JSP file as part of a JSP element. The tag is distinguishable as markup, as opposed to
data, because it is surrounded by angle brackets.
JSP tag library
A collection of tags identifying custom actions described via a tag library descriptor
and Java classes. A portable Java class library that has a unique URI and that defines
custom tags that perform specialized tasks. A JSP tag library can be imported into any JSP
file and used with various scripting languages.
Java Studio(TM)
The first program that allows you to easily create Java(TM) technology-based
applications and applets without having to know the Java programming language.
Java(TM) Technologies
A set of technologies that enable the creation and safe running of software programs in
both stand-alone and networked environments.
Java(TM) Transaction API (JTA)
An API that allows applications and J2EE servers to access transactions.
Java(TM) Transaction Service (JTS)
Specifies the implementation of a transaction manager which supports JTA and implements
the Java mapping of the OMG Object Transaction Service (OTS) 1.1 specification at the
level below the API.
Java(TM) virtual machine (JVM)*
A software "execution engine" that safely and compatibly executes the byte
codes in Java class files on a microprocessor (whether in a computer or in another
electronic device).
Java HotSpot performance engine - the ultra-high-performance engine for a Java runtime
environment which features an adaptive compiler that dynamically optimizes the performance
of running applications.
KJava virtual machine - the small-footprint, highly optimized foundation of a runtime
environment within the Java 2 Platform, Micro Edition. Derived from the Java virtual
machine, it is targeted at small connected devices and can scale from 30KB to
approximately 128KB, depending on the target device's functionality.
Java Card Virtual Machine - an ultra-small-footprint, highly-optimized foundation of a
runtime environmentwithin the Java 2 Platform, Micro Edition. Derived from the Java
virtual machine, it is targeted at smart cards and other severely memory-constrained
devices and can run in devices with memory as small as 24K of ROM, 16K of EEPROM, and 512
bytes of RAM.
Java Web Server(TM)
The easy-to-use, extensible, easy-to-administer, secure, platform-independent solution
to speed and simplify the deployment and management of your Internet and Intranet Web
sites. It provides immediate productivity for robust, full-featured, Java technology-based
server applications.
Java Workshop(TM)
A complete set of tools integrated into a single environment for managing programming
with Java technology. The Java Workshop software uses a highly modular structure that
enables you to easily plug new tools into the overall structure.
Java(TM) wallet
A user interface, built on the Java(TM) Electronic Commerce Framework, which allows for
online purchases, value transfers, and administrative functions.
JavaSpaces(TM)
A technology that provides distributed persistence and data exchange mechanisms for code
in the Java(TM) programming language.
JavaSoft(TM)
A former business unit of Sun Microsystems, Inc., currently known as Sun Microsystems,
Inc., Java Software division.
JDBC(TM)
Java(TM) Database Connectivity. An industry standard for database-independent
connectivity between the Java platform and a wide range of databases. The JDBC interface
provides a call-level API for SQL-based database access.
JDK(TM)
Java(TM) Development Kit software. A software development environment for writing
applets and application in the Java programming language.
JFC
Java(TM) Foundation Class. An extension that adds graphical user interface class
libraries to the Abstract Windowing Toolkit (AWT).
Jini(TM) Technology
a set of Java APIs that may be incorporated an optional package for any Java 2 Platform
Edition. The Jini APIs enable transparent networking of devices and services and
eliminates the need for system or network administration intervention by a user.
The Jini technology is currently an optional package available on all Java platform
editions.
JMAPI
Java(TM) Management API. A collection of Java programming language classes and
interfaces that allow developers to build system, network, and service management
applications.
JMS
See: Java Message Service (JMS)
JNDI
Java Naming and Directory Interface(TM). A set of APIs that assist with the interfacing
to multiple naming and directory services.
JPEG
Joint Photographic Experts Group. An image file compression standard established by this
group. It achieves tremendous compression at the cost of introducing distortions into the
image which are almost always imperceptible.
JRE
Java(TM) runtime environment. A subset of the Java Developer Kit for end-users and
developers who want to redistribute the runtime environment. The Java runtime environment
consists of the Java virtual machine*, the Java core classes, and supporting files.
Just-in-time (JIT) Compiler
A compiler that converts all of the bytecode into native machine code just as a Java(TM)
program is run. This results in run-time speed improvements over code that is interpreted
by a Java virtual machine*.
The Java(TM) programming language sets aside words as keywords - these words are
reserved by the language itself and therefore are not available as names for variables or
methods.
Pertaining to how the characters in source code are translated into tokens that the
compiler can understand.
linker
A module that builds an executable, complete program from component machine code
modules. The Java(TM) linker creates a runnable program from compiled classes. See also
The basic representation of any integer, floating point, or character value. For
example, 3.0 is a double-precision floating point literal, and "a" is a
character literal.
A data item known within a block, but inaccessible to code outside the block. For
example, any variable defined within a method is a local variable and can't be used
outside the method.
long
A Java(TM) programming language keyword used to define a variable of type long.
. Unless specified otherwise, a method is not
static.
method permission
A permission to invoke a specified group of methods of an enterprise bean's home and
remote interfaces.
module
A software unit that consists of one or more J2EE components of the same container type
and one deployment descriptor of that type. There are three types of modules: EJB, Web,
and application client. Modules can be deployed as stand-alone units or assembled into an
application.
A program that provides a simple GUI that enables easy access to the data stored on the
Internet. These data may be simple files or hypertext documents. Mosaic was written by a
team at
A Java(TM) programming language keyword that is used in method declarations to specify
that the method is not implemented in the same Java source file, but rather in another
language.
NCSA
National Center for Supercomputer Applications. See also
A Java(TM) programming language keyword used to create an instance of a class.
null
The null type has one value, the null reference, represented by the literal null, which
is formed from ASCII characters. A null literal is always of the null type.
The numbering system using 8 as its base, using the numerals 0-7 as its digits. In
programs written in the Java(TM) programming language, octal numbers must be preceded with
0. See also
The Open Net Environment (ONE), orginated by Sun Microsystems and backed by major
industry participants, describes a comprehensive architecture for the creation, assembly
and deployment of web services. ONE is both platform-independent and based entirely on
open standards. Sun ONE refers to a particular implementation of this architecture by Sun
and iPlanet.
Optional Packages
The set or sets of APIs in a Java platform edition which are available with and may be
supported in a compatible implementation.
Over time, optional packages may become required in an edition as the marketplace requires
them.
ORB
Object Request Broker. A library than enables CORBA objects to locate and communicate
with one another.
OS principal
A principal native to the operating system on which the J2EE platform is executing.
OTS
Object Transaction Service. A definition of the interfaces that permit CORBA objects to
participate in transactions.
overloading
Using one identifier to refer to multiple items in the same scope. In the Java(TM)
programming language, you can overload methods but not variables or operators.
overriding
Providing a different implementation of a method in a subclass of the class that
originally defined the method.
In networking, any functional unit in the same layer as another entity.
persistence
The protocol for transferring the state of an entity bean between its instance variables
and an underlying database.
PersonalJava(TM)
A Java runtime environment for network-connectable applications on personal consumer
devices for home, office, and mobile use.
pixel
The picture element on a display area, such as a monitor screen or printed page. Each
pixel is individually accessible.
POA
Portable Object Adapter. A CORBA standard for building server-side applications that are
portable across heterogeneous ORBs.
POSIX
Portable Operating System for UNIX(TM). A standard that defines the language interface
between the UNIX operating system and application programs through a minimal set of
supported functions.
primary key
An object that uniquely identifies an entity bean within a home.
principal
The identity assigned to an entity as a result of authentication.
private
A Java(TM) programming language keyword used in a method or variable declaration. It
signifies that the method or variable can only be accessed by other elements of its class.
privilege
A security attribute that does not have the property of uniqueness and which may be
shared by many principals. An example of a privilege is a group.
A virtual address space containing one or more threads.
property
Characteristics of an object that users can set, such as the color of a window.
Profiles
A Profile is a collection of Java APIs that complements one or more Java 2 Platform
Editions by adding domain-specific capabilities. Profiles may also include other defined
Profiles. A profile implementation requires a Java 2 Platform Edition to create a complete
development and deployment environment in a targeted vertical market. Each profile is
subject to an associated set of compatibility requirements.
Profiles may be usable on one or more editions.
Some examples of profiles within the Java 2 Platform, Micro Edition are:
* PersonalJava(TM) - for non-PC products that need to display web-compatible Java-based
content
* Java Card(TM) - for secure smart cards and other severely memory-constrained devices.
protected
A Java(TM) programming language keyword used in a method or variable declaration. It
signifies that the method or variable can only be accessed by elements residing in its
class, subclasses, or classes in the same package.
public
A Java(TM) programming language keyword used in a method or variable declaration. It
signifies that the method or variable can be accessed by elements residing in other
classes.
See security policy domain. Also, a string, passed as part of an HTTP request during
basic authentication, that defines a protection space. The protected resources on a server
can be partitioned into a set of protection spaces, each with its own authentication
scheme and/or authorization database.
re-entrant enterprise bean
An enterprise bean that can handle multiple simultaneous, interleaved, or nested
invocations which will not interfere with each other.
reference
A data element whose value is an address.
Reference Implementation
See Java 2 SDK, Enterprise Edition.
remote interface
One of two interfaces for an enterprise bean. The remote interface defines the business
methods callable by a client.
remove method
Method defined in the home interface and invoked by a client to destroy an enterprise
bean.
resource adapter
A system-level software driver that is used by an EJB container or an application client
to connect to an EIS. A resource adapter is typically specific to an EIS. It is available
as a library and is used within the address space of the server or client using it. A
resource adapter plugs in to a container. The application components deployed on the
container then use the client API (exposed by adapter) or tool generated high-level
abstractions to access the underlying EIS. The resource adapter and EJB container
collaborate to provide the underlying mechanisms - transactions, security, and connection
pooling - for connectivity to the EIS.
resource manager
Provides access to a set of shared resources. A resource manager participates in
transactions that are externally controlled and coordinated by a transaction manager. A
resource manager is typically in different address space or on a different machine from
the clients that access it. Note: An EIS is referred to as resource manager when it is
mentioned in the context of resource and transaction management.
resource manager connection
An object that represents a session with a resource manager.
resource manager connection factory
An object used for creating a resource manager connection.
return
A Java(TM) programming language keyword used to finish the execution of a method. It can
be followed by a value required by the method definition.
The function performed by a person in the development and deployment phases of an
application developed using J2EE technology. The roles are: Application Application
Component Provider, Application Assembler, Deployer, J2EE Platform Provider, EJB Container
Provider, EJB Server Provider, Web Container Provider, Web Server Provider, Tool Provider,
and System Administrator.
role (security)
An abstract logical grouping of users that is defined by the Application Assembler. When
an application is deployed, the roles are mapped to security identities, such as
principals or groups, in the operational environment.
role mapping
The process of associating the groups and/or principals recognized by the container to
security roles specified in the deployment descriptor. Security roles have to be mapped by
the Deployer before the component is installed in the server.
rollback
The point in a transaction when all updates to any databases involved in the transaction
are reversed.
root
In a hierarchy of items, the one item from which all other items are descended. The root
item has nothing above it in the hierarchy. See also
The software environment in which programs compiled for the Java(TM) virtual machine*
can run. The runtime system includes all the code necessary to load programs written in
the Java programming language, dynamically link native methods, manage memory, handle
exceptions, and an implementation of the Java virtual machine, which may be a Java
interpreter.
Simple API for XML. An event-driven, serial-access mechanism for accessing XML
documents.
Sandbox
Comprises a number of cooperating system components, ranging from security managers that
execute as part of the application, to security measures designed into the Java(TM)
virtual machine* and the language itself. The sandbox ensures that an untrusted,
and possibly malicious, application cannot gain access to system resources.
scope
A characteristic of an identifier that determines where the identifier can be used. Most
identifiers in the Java(TM) programming environment have either class or local scope.
Instance and class variables and methods have class scope; they can be used outside the
class and its subclasses only by prefixing them with an instance of the class or (for
class variables and methods) with the class name. All other variables are declared within
methods and have local scope; they can be used only within the enclosing block.
Secure Socket Layer (SSL)
A protocol that allows communication between a Web browser and a server to be encrypted
for privacy.
security attributes
A set of properties associated with a principal. Security attributes can be associated
with a principal by an authentication protocol and/or by a J2EE Product Provider.
security constraint
A declarative way to annotate the intended protection of Web content. A security
constraint consists of a Web resource collection, an authorization constraint, and a user
data constraint.
security context
An object that encapsulates the shared state information regarding security between two
entities.
security permission
A mechanism, defined by J2SE, used by the J2EE platform to express the programming
restrictions imposed on Application Component Providers.
security permission set
The minimum set of security permissions that a J2EE Product Provider must provide for
the execution of each component type.
security policy domain
A scope over which security policies are defined and enforced by a security
administrator. A security policy domain has the following characteristics:
It has a collection of users (or principals).
It uses a well defined authentication protocol(s) for authenticating users (or
principals).
It may have groups to simplify setting of security policies.
security role
See role (security).
security technology domain
A scope over which the same security mechanism is used to enforce a security policy.
Multiple security policy domains can exist within a single technology domain.
server principal
The OS principal that the server is executing as.
servlet
A Java program that extends the functionality of a Web server, generating dynamic
content and interacting with Web clients using a request-response paradigm.
servlet container
A container that provides the network services over which requests and responses are
sent, decodes requests, and formats responses. All servlet containers must support HTTP as
a protocol for requests and responses, but may also support additional request-response
protocols such as HTTPS.
servlet container, distributed
A servlet container that can run a Web application that is tagged as distributable and
that executes across multiple Java virtual machines running on the same host or on
different hosts.
servlet context
An object that contains a servlet's view of the Web application within which the servlet
is running. Using the context, a servlet can log events, obtain URL references to
resources, and set and store attributes that other servlets in the context can use.
servlet mapping
Defines an association between a URL pattern and a servlet. The mapping is used to map
requests to servlets. If the container handling the request is a JSP container, a URL
containing a .jsp extension is implicitly mapped.
session
An object used by a servlet to track a user's interaction with a Web application across
multiple HTTP requests.
session bean
An enterprise bean that is created by a client and that usually exists only for the
duration of a single client/server session. A session bean performs operations, such as
calculations or accessing a database, for the client. While a session bean may be
transactional, it is not recoverable should a system crash occur. Session bean objects can
be either stateless or they can maintain conversational state across methods and
transactions. If they do maintain state, then the EJB container manages this state if the
object must be removed from memory. However, the session bean object itself must manage
its own persistent data.
short
A Java(TM) programming language keyword used to define a variable of type short.
Standardized Generalized Markup Language. An ISO/ANSI/ECMA standard that specifies a way
to annotate text documents with information about types of sections of a document.
Smart Web Services
Smart Web Services extend the basic concept of web services by adding the dimension of
user context, and are able to to modify their operation to track along with changes in a
user's current situation. This inlcudes the classic "who, what, when, where,
why" descriptors that come together to define a user's context at a any given moment.
SOAP
The Simple Object Access Protocol (SOAP) uses a combination of XML-based data
structuring and the Hyper Text Transfer Protocol (HTTP) to define a standardized method
for invoking methods in objects distributed in diverse operating environments across the
internet.
SQL
Structured Query Language. The standardized relational database language for defining
database objects and manipulating data.
stateful session bean
A session bean with a conversational state.
stateless session bean
A session bean with no conversational state. All instances of a stateless session bean
are identical.
static
A Java(TM) programming language keyword used to define a variable as a class variable.
Classes maintain one copy of class variables regardless of how many instances exist of
that class. "static" can also be used to define a method as a class method.
Class methods are invoked by the class instead of a specific instance, and can only
operate on class variables.
A stream is simply a byte-stream of data that is sent from a sender to a receiver. There
are two basic categories, so the java.io package includes two abstract clasess
(InputStream and OutputStream).
A Java(TM) programming language keyword used to evaluate a variable that can later be
matched with a value specified by the "case" keyword in order to execute a group
of statements.
The code name for a collection of graphical user interface (GUI) components that runs
uniformly on any native platform which supports the Java(TM) virtual machine*.
Because they are written entirely in the Java programming language, these components may
provide functionality above and beyond that provided by native-platform equivalents.
(Contrast with AWT.)
synchronized
A keyword in the Java programming language that, when applied to a method or code block,
guarantees that at most one thread at a time executes that code.
System Administrator
The person responsible for configuring and administering the enterprise's computers,
networks, and software systems.
Transmission Control Protocol based on IP. This is an Internet protocol that provides
for the reliable delivery of streams of data from one host to another. See also
A test suite, a set of tools, and other requirements used to certify an implementation
of a particular Sun technology conformant both to the applicable specifications and to Sun
or Sun-designated reference implementations.
Thin Client
A system that runs a very light operating system with no local system administration and
executes applications delivered over the network.
this
A Java(TM) programming language keyword that can be used to represent an instance of the
class in which it appears. "this" can be used to access class variables and
methods.
The basic unit of program execution. A process can have several threads running
concurrently, each performing a different job, such as waiting for events or performing a
time-consuming job that the program doesn't need to complete before going on. When a
thread has finished its job, the thread is suspended or destroyed. See also
A Java(TM) programming language keyword that allows the user to throw an exception or
any class that implements the "throwable" interface.
throws
A Java(TM) programming language keyword used in method declarations that specify which
exceptions are not handled within the method but rather passed to the next higher level of
the program.
Tool Provider
An organization or software vendor that provides tools used for the development,
packaging, and deployment of J2EE applications.
transaction
An atomic unit of work that modifies data. A transaction encloses one or more program
statements, all of which either complete or roll back. Transactions enable multiple users
to access the same data concurrently.
transaction attribute
A value specified in an enterprise bean's deployment descriptor that is used by the EJB
container to control the transaction scope when the enterprise bean's methods are invoked.
A transaction attribute can have the following values:
Required, RequiresNew, Supports, NotSupported, Mandatory, Never.
transaction isolation level
The degree to which the intermediate state of the data being modified by a transaction
is visible to other concurrent transactions and data being modified by other transactions
is visible to it.
transaction manager
Provides the services and management functions required to support transaction
demarcation, transactional resource management, synchronization, and transaction context
propagation.
transient
A keyword in the Java programming language that indicates that a field is not part of
the serialized form of an object. When an object is serialized, the values of its
transient fields are not included in the serial representation, while the values of its
non-transient fields are included.
try
A Java(TM) programming language keyword that defines a block of statements that may
throw a Java language exception. If an exception is thrown, an optional "catch"
block can handle specific exceptions thrown within the "try" block. Also, an
optional "finally" block will be executed regardless of whether an exception is
thrown or not.
The Universal Description Discovery and Integration (UDDI) project provides a global,
public, XML-based, online business registry where businesses register and advertise their
web services. UDDI defines an Internet version of the white and yellow pages in a
telephone directory.
.
All source code in the Java(TM) programming environment is written in Unicode.
URI
Uniform Resource Identifier. A compact string of characters for identifying an abstract
or physical resource. A URI is either a URL or a URN. URLs and URNs are concrete entities
that actually exist; A URI is an abstract superclass.
URL
Uniform Resource Locator. A standard for writing a text reference to an arbitrary piece
of data in the WWW. A URL looks like "protocol://host/localinfo" where protocol
specifies a protocol to use to fetch the object (like HTTP or FTP), host specifies the
Internet name of the host on which to find it, and localinfo is a string (often a file
name) passed to the protocol handler on the remote host.
URL path
The URL passed by a HTTP request to invoke a servlet. The URL consists of the Context
Path + Servlet Path + PathInfo, where Context Path is the path prefix associated with a
servlet context that this servlet is a part of. If this context is the default context
rooted at the base of the web server's URL namespace, the path prefix will be an empty
string. Otherwise, the path prefix starts with a / character but does not end with a /
character. Servlet Path is the path section that directly corresponds to the mapping which
activated this request. This path starts with a / character. PathInfo is the part of the
request path that is not part of the Context Path or the Servlet Path.
URN
Uniform Resource Name. A unique identifier that identifies an entity, but doesn't tell
where it is located. A system can use a URN to look up an entity locally before trying to
find it on the Web. It also allows the Web location to change, while still allowing the
entity to be found.
user data constraint
Indicates how data between a client and a container should be protected. The protection
can be the prevention of tampering with the data or prevention of eavesdropping on the
data.
An abstract specification for a computing device that can be implemented in different
ways, in software or hardware. You compile to the instruction set of a virtual machine
much like you'd compile to the instruction set of a microprocessor. The Java(TM) virtual
machine* consists of a bytecode instruction set, a set of registers, a stack, a
garbage-collected heap, and an area for storing methods.
vocabulary
Traditionally, software programs have been written and then compiled into machine code
that is directly dependent on the operating system that drives the microprocessor in the
computer. The Java platform mitigates this dependency by providing a model in which
software is written and compiled, and can then be transmitted over a network and run
anywhere a fully compliant virtual machine is present.
This model provides the additional benefit of heightened security, both because programs
can be verified by the virtual machine after they have been transmitted over a network,
and because the virtual machine can run programs in a secure "sandbox" that
prevents certain destructive behaviors.
Software programmers have embraced the Java platform because it reduces the cost and time
required to write and support software code. They are no longer required to rewrite
software to function on different computers with different operating systems and
microprocessors. Companies and organizations deploying applications favor Java technology
because it minimizes the cost of purchasing or modifying different versions of software
applications for the various types of computers and servers within their networks.
void
A Java(TM) programming language keyword used in method declarations to specify that the
method does not return any value. "void" can also be used as a nonfunctional
statement.
volatile
A Java(TM) programming language keyword used in variable declarations that specifies
that the variable is modified asynchronously by concurrently running threads.
A UNIX® command which will wait for all background processes to complete, and report
their termination status.
Web application, distributable
A Web application that uses J2EE technology written so that it can be deployed in a Web
container distributed across multiple Java virtual machines running on the same host or
different hosts. The deployment descriptor for such an application uses the distributable
element.
Web component
A component that provides services in response to requests; either a servlet or a JSP
page.
Web container
A container that implements the Web component contract of the J2EE architecture. This
contract specifies a runtime environment for Web components that includes security,
concurrency, life cycle management, transaction, deployment, and other services. A
container that provides the same services as a JSP container and federated view of the
J2EE platform APIs. A Web container is provided by a Web or J2EE server.
Web container, distributed
A Web container that can run a Web application that is tagged as distributable and that
executes across multiple Java virtual machines running on the same host or on different
hosts.
Web server
Software that provides services to access the Internet, an intranet, or an extranet. A
Web server hosts Web sites, provides support for HTTP and other protocols, and executes
server-side programs (such as CGI scripts or servlets) that perform certain functions. In
the J2EE architecture, a Web server provides services to a Web container. For example, a
Web container typically relies on a Web server to provide HTTP message handling. The J2EE
architecture assumes that a Web container is hosted by a Web server from the same vendor,
so does not specify the contract between these two entities. A Web server may host one or
more Web containers.
Web Services
Web Services are loosely coupled software components capable of collaborating with each
other over multiple networks to deliver a specific result to an end user. In the process,
they leverage an emerging group of standards that govern their description and
interaction, including SOAP (Simple Object Access Protocol), UDDI (Universal Discovery and
Description Initiative), XML (Extensible Markup Language), and WSDL (Web Services
Description Language).
while
A Java(TM) programming language keyword used to declare a loop that iterates a block of
statements. The loop`s exit condition is specified as part of the while statement.
world readable files
Files on a file system that can be viewed (read) by any user. For example: files
residing on web servers can only be viewed by Internet users if their permissions have
been set to world readable.
wrapper
An object that encapsulates and delegates to another object to alter its interface or
behavior in some way.
WSDL
The Web Services Description Language (WSDL) is an XML language that is used to describe
a web service and to specify how to communicate with the web service.
WWW
World Wide Web. The web of systems and the data in them that is the Internet. See also
Extensible Markup Language. A markup language that allows you to define the tags
(markup) needed to identify the data and text in XML documents. J2EE deployment
descriptors are expressed in XML.