HP NonStop G-Series - Manual (Page 65)

6. Using the Jolt Class Library
The Jolt Class Library provides developers with a set of new object-oriented Java language classes for accessing NonStop TUXEDO
services. These classes allow you to extend applications for Internet and intranet transaction processing. The application developer can use
the Jolt Class Library to customize access to NonStop TUXEDO services from Java applets. The following Jolt topics are included in this
chapter:
Class Library Functionality Overview ●
Jolt Object Relationships ●
Jolt Class Functionality ●
Jolt Class Library Walk-through ●
Using TUXEDO Buffer Types with Jolt ●
Multithreaded Applications ●
Event Subscription and Notifications ●
Clearing Parameter Values ●
Reusing Objects ●
Application Deployment and Localization ●
To use the information in the following sections, you need to be generally familiar with the Java programming language and
object-oriented programming concepts. All of the programming examples are in Java code.
Note
All of the program examples are only fragments used to illustrate Jolt capabilities. They are
not intended to be compiled and run as provided. These program examples require additional
code to be fully executable.
Class Library Functionality Overview
The Jolt Class Library provides the TUXEDO application developer with the tools to develop client-side applications or applets that will
run in a Java-enabled Web browser or as an independent Java application. The bea.jolt package contains the Jolt Class Library. To use the
Jolt Class Library, the client program or applet must import this package. For an example of how to import the bea.jolt package, refer to
Example 6-1 .
Java Applications vs. Java Applets
Java programs that run in a browser are called "applets." Applets are intended to be small, easily downloaded parts of an overall
application that perform specific functions. Many popular browsers impose limitations on the capabilities of Java applets for the purpose
of providing a high degree of security for the users of the browser. The following are some of the restrictions imposed on applets:
An applet ordinarily cannot read or write files on any host system. ●
An applet cannot start any program on the host (client) that is executing the applet. ●
An applet can make a network connection only to the host where it originated; it cannot make other network connections, not even
to the client machine. ●
Programming workarounds exist for most of the restrictions on Java applets. Check your browser's web site (e.g., www.netscape.com or
www.microsoft.com) or developer documentation for specific information about the applet capabilities that the browser supports or
restricts. You can also use Jolt Relay to overcome some of the network connection restrictions.
A Java application, however, is not run in the context of a browser and is not restricted in the same ways. For example, a Java application
can start another application on the host machine where it is executing. While an applet relies on the windowing environment of a browser
or appletviewer for much of its user interface, a Java application requires that you create your own user interface. An applet is designed to
be small and highly portable. A Java application, on the other hand, can operate much like any other non-Java program. The security
restrictions for applets imposed by various browsers and the scope of the two program types are the most important differences between a
Java application and a Java applet.