A Java program that is run from inside a web browser.
The html page loaded into the web
browser contains an applet tag, which tells the browser
where to find the Java .class files.
What are applets prevented from doing?
In general, applets loaded over the net
are prevented from reading and writing files on
the client file system, and from making
network connections except to the originating host.
In addition, applets loaded over the net
are prevented from starting other programs on
the client. Applets loaded over the net are also
not allowed to load libraries, or to define
native method calls. If an applet could define native method calls,
that would give the applet direct access to the underlying computer.
In Java-enabled browsers, untrusted applets cannot
read or write files at all. By default,
downloaded applets are considered untrusted.
There are two ways for an applet to be considered
1.The applet is installed on the local hard disk,
in a directory on the CLASSPATH used by the program that
you are using to run the applet. Usually, this is a
Java-enabled browser, but it could be the appletviewer,
or other Java programs that know how to load applets.
2.The applet is signed by an identity marked as trusted
in your identity database.
The applicances are the resources to be managed.
The resources range in size from a large
server to a network element. A Java terminal can
be thought of as an appliance as well as a DNS server.
Though these machines perform radically different functions,
they are managed through the Managed Object Server and are required
to have JMAPI agent software installed. JMAPI's strategy
is to push management close to managed devices with dynamic downloading of agents.
The Beans Development Kit (BDK) is intended
to support the early development of JavaBeans
components and to act as a standard reference base
for both bean developers and tool vendors.
The BDK provides a reference bean container,
the "BeanBox" and a variety of reusable example
source code (in the demo and beanbox subdirectories)
for use by both bean developers and tools developers.
The BDK 1.0 release requires you to have installed
the Java Development Kit (JDK) 1.1.
The BDK is qualified for Solaris 2.4, Solaris 2.5,
Windows 95, Windows NT 3.5.1, and Windows NT 4.0.
However the BDK is "pure Java" and should run on any
JDK 1.1 enabled system.
The EmbeddedJava architecture is similar to other Java platforms.
It includes Java class libraries
and the Java Virtual Machine (VM) that runs on top of an operating environment,
These classes have API's that are compatible with their JDK 1.1
counterparts but have implementations that have been optimized
for embedded devices. The set of classes available to a licensee
for building an EmbeddedJava device include all of the classes in
the JDK 1.1 Java Platform Core API with the exception of the
java.applet package. They are either supplied by JavaSoft
directly or through an RTOS reseller.
A Java platform represents a set of technology and
product configurations that distinguish it
from other Java platforms. The EmbeddedJava platform includes a Java VM and a set of
Java classes that have been optimized for dedicated-purpose embedded devices.
Enerprize Java Beans
The Enterprise JavaBeans 1.0 component architecture makes it easy for developers
to create, deploy and manage cross-platform, component-based server applications
that easily integrate with their existing system services and applications. The
Enterprise JavaBeans architecture delivers the speed, simplicity and reusability of
JavaBeans component development along with the added scalability and security
needed for enterprise server applications. Using the Enterprise JavaBeans
technology, developers can create rich, flexible, components that reflect complex
business processes. These components can then be easily extended as a business
"Enterprise JavaBeans has received broad endorsement and is rapidly being
adopted as the standard for component-based development on the server. The
industry helped build the Enterprise JavaBeans specification and the industry will
announce products based on this specification at JavaOne '98," said Kannegaard.
"We are pleased to see this kind of momentum. Enterprise JavaBeans opens up a
whole new enterprise software market."
Enterprise JavaBeans extends Java's
"Write Once, Run Anywhere" capability to
reusable components everywhere!
Java Enerprise APIs includes
JavaBeans components, HTML, IIOP,
other protocols, Servlets, EJB components
Java Enerprise APIs:JTS,
A lightweight, highly customizable solution for OEMs and
developers creating Web-enabled devices and applications.
HotJava Browser's small footprint makes it an ideal, scalable
solution for a variety of devices--from NCs to PCs.
HotJava Browser features include customizability, extensibility,
flexible security model, SSL (Secure Sockets Layer) capability,
and internationalization support.
The Java platform is a fundamentally new way of
computing, based on the power of networks and the idea that
the same software should run on many different kinds of
computers, consumer gadgets, and other devices.
With Java technology, you can use the same application from
any kind of machine -- a Unix workstation, a PC, a Macintosh computer,
a network computer, or even new technologies like Internet screen phones.
The Java 2D Application Programming Interface (API)
provides a powerful, flexible framework for using device- and
resolution-independent graphics in Java programs. The Java
2D API extends the graphics and imaging classes defined by
java.awt, while maintaining compatibility for existing
programs. The Java 2D API enables developers to easily
incorporate high-quality 2D graphics, text, and images in Java
applications and applets.
Authored primarily by Sun and Adobe Systems Incorporated,
the Java 2D API provides a two-dimensional imaging model
for line art, text, and images that uniformly addresses color,
spatial transformations, and compositing. With the Java 2D
API, you use the same imaging model for both screen and
print, which provides a highly WYSIWYG (What You See Is What You
Get) experience for the user.
Java 3D innovative features:
High-level, object-oriented, scene-graph-based programming
paradigm that enables rapid deployment of sophisticated
applications and applets that will run anywhere Java is
High-performance rendering of 3D graphical data
Implementations can perform sophisticated optimizations
such as culling, pruning, parallel scene-graph traversal,
Rendering can be layered on top of existing low-level 3D APIs
Rich set of features for creating and visualizing interesting 3D
3D geometric primitives: Triangles, lines, points
3D spatialized sound
Lighting and shading
Sophisticated viewing model seamlessly supports
monoscopic or stereo viewing--with or without a
head-tracker--in a wide variety of display
Window on a standard CRT display
Full-screen "fish-tank" VR mode
Advanced behavioral model supports user-specified
behaviors and execution culling
Advanced input/sensor model includes support for
6-degree-of-freedom tracking devices.
Support for runtime loaders to accommodate a wide variety of
file formats, such as vendor-specific CAD formats,
interchange formats, VRML 1.0, and VRML 2.0
This package provides the tools that enable assistive
technologies to interact with the accessibility support built into
the Java Foundation Classes and track top level window
creation and other events. Tools for evaluating the accessibility
of information contained in components to assistive
technologies are also contained in the package.
The AWT Monitor allows you to obtain information about objects being displayed on the
screen by a particular JavaTM Virtual Machine, and does not require the Java
The Java Monitor allows you to obtain information about objects being displayed on the
screen by a particular Java Virtual Machine, and provides extended support for the
Java Foundation Classes.
If you have used Delphi, or Visual Basic, you are already familiar
with the notion of a bean. The idea is the same;
the programming language is different.
A Java Bean is a reusable software component that works with Java.
More specifically: a Java Bean is a reusable software
component that can be visually manipulated in builder tools.
Many beans are AWT components, but it is also quite possible,
and often useful, to write "invisible" beans that do not have an
on-screen appearance. (Just because a bean does not have
an on-screen appearance in a finished application does
not mean that it won't be visually manipulated by a beanbox tool, however.)
In addition to the regular sort of properties described above,
the JavaBeans API also provides support for "indexed properties,"
"bound properties," and "constrained properties." An indexed property is
any property that has an array value and for which the bean provides
methods to get and set individual elements of the array,
as well as methods to get and set the entire array. A bound property is
one that sends out a notification event when its value changes,
while a constrained property is one that sends out a notification event
when its value changes and allows the change to be vetoed by listeners.