Using Oracle Jolt

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Introducing Oracle Jolt

Oracle Jolt is a Java-based interface to the Oracle Tuxedo system that extends the functionality of existing Oracle Tuxedo applications to include Intranet- and Internet-wide availability. Using Jolt, you can now easily transform any Oracle Tuxedo application so that its services are available to customers using an ordinary browser on the Internet. Jolt interfaces with existing and new Oracle Tuxedo applications and services to allow secure, scalable, intranet/Internet transactions between client and server. Jolt enables you to build client applications and applets that can remotely invoke existing Oracle Tuxedo services, such as application messaging, component management, and distributed transaction processing.

Because you develop your applications with the Jolt API and the Jolt Repository Editor, which use Oracle Tuxedo and the Java programming language, the Jolt documentation is written with the assumption that you are familiar with Oracle Tuxedo and Java programming. This documentation is intended for system administrators, network administrators, and developers.

This topic includes the following sections:

 


Oracle Jolt Components

Oracle Jolt is a Java class library and API that provides an interface to Oracle Tuxedo from remote Java clients. Oracle Jolt consists of the following components for creating Java-based client programs that access Oracle Tuxedo services:

 


Key Features

With Oracle Jolt, you can leverage existing Oracle Tuxedo services and extend your transaction environment to the corporate intranet or world-wide Internet. The key feature of Jolt architecture is its simplicity. You can build, deploy, and maintain robust, modular, and scalable electronic commerce systems that operate over the Internet.

Oracle Jolt includes the following features:

 


How Oracle Jolt Works

Oracle Jolt connects Java clients to applications that are built using the Oracle Tuxedo system. The Oracle Tuxedo system provides a set of modular services, each offering specific functionality related to the application as a whole.

The end-to-end view of the Oracle Jolt architecture, as well as related Oracle Tuxedo components and their interactions, is illustrated in the figure Oracle Jolt Architecture.

Using Figure 1-1 as an example, a simple banking application might have services such as INQUIRY, WITHDRAW, TRANSFER, and DEPOSIT. Typically, service requests are implemented in C or COBOL as a sequence of calls to a program library. Accessing a library from a native program means installing the library for the specific combination of CPU and operating system release on the client machine, a situation that Java was expressly designed to avoid. The Jolt Server implementation acts as a proxy for the Jolt client, invoking the Oracle Tuxedo service on behalf of the client. The Oracle Jolt Server accepts requests from the Jolt clients and maps those requests into Oracle Tuxedo service requests.

Figure 1-1 Oracle Jolt Architecture

Oracle Jolt Architecture

Jolt Servers

The following Jolt Server components act in concert to pass Jolt client transaction processing requests to the Oracle Tuxedo application.

Figure 1-2 illustrates the Jolt Server and Jolt Repository components.

Figure 1-2 Jolt Server and Repository Components

Jolt Server and Repository Components

Jolt Class Library

The Oracle Jolt Class Library is a set of classes that you can use in your Java application or applet to make service requests to the Oracle Tuxedo system from a Java-enabled client. You access Oracle Tuxedo transaction services by using Jolt class objects.

When developing a Jolt client application, you only need to know about the classes that Jolt provides and the Oracle Tuxedo services that are exported by the Jolt Repository. Jolt hides the underlying application details. To use Jolt and the Jolt Class Library, you do not need to understand: the underlying transactional semantics, the language in which the services were coded, buffer manipulation, the location of services, or the names of databases used.

The Jolt API is a Java class library and has the benefits that Java provides: applets are downloaded dynamically and are only resident during run time. As a result, there is no need for client installation, administration, management, or version control. If services are changed, the client application notes the changes at the next call to the Jolt Repository.

Figure 1-3 shows the flow of activity from a Jolt client to and from the Oracle Tuxedo system. The call-out numbers correspond to descriptions of the activity in the table Using the Jolt Class Library.

Figure 1-3 Using the Jolt Class Library to Access Oracle Tuxedo Services

Using the Jolt Class Library to Access Oracle Tuxedo Services

Table 1-1 briefly describes the flow of activity involved in using the Jolt Class Library to access Oracle Tuxedo services, as shown in the previous figure Using the Jolt Class Library to Access Oracle Tuxedo Services.

Table 1-1 Using the Jolt Class Library 
Process
Step
Action
Connection

1

A Java-enabled Web browser uses HTTP protocol to download an HTML page.
...

2

A Jolt applet is downloaded and executed in the Java Virtual Machine on the client.
...

3

The first Java applet task is to open a separate connection to the Jolt Server.
Request

4

The Jolt client now knows the signature of the service (such as name, parameters, types); can build a service request object based on Jolt class definitions, and make a method call.
...

5

The request is sent to the Jolt Server, which translates the Java-based request into an Oracle Tuxedo request and forwards the request to the Oracle Tuxedo environment.
Reply

6

The Oracle Tuxedo system processes the request and returns the information to the Jolt Server, which translates it back to the Java applet.

JoltBeans

Oracle Jolt now includes JoltBeans, Java beans components that you use in a Java-enabled integrated development environment (IDE) to construct Oracle Jolt clients. Using JoltBeans, and popular JavaBeans-enabled development tools such as Symantec Visual Café, you can graphically create client applications.

Oracle JoltBeans provide a JavaBeans-compliant interface to Oracle Jolt that enables you to develop a fully functional Oracle Jolt client without writing any code. You can drag and drop JoltBeans from the component palette of a development tool and position them on the Java form (or forms) of the Jolt client application you are creating. You can populate the properties of the beans and graphically establish event source-listener relationships between various beans of the application or applet. Typically, the development tool is used to generate the event hook-up code, or you can code the hook-up manually. Client development with JoltBeans is integrated with the Oracle Jolt Repository, which provides easy access to available Oracle Tuxedo functions.

Jolt Server and Jolt Client Communication

The Jolt system handles all communication between the Jolt Server and the Jolt client using the Oracle Jolt Protocol. The communication process between the Jolt Server and the Jolt client applet or applications functions as follows:

  1. Oracle Tuxedo service requests and associated parameters are packaged into a message buffer and delivered over the network to the Jolt Server.
  2. The Jolt Server unpacks the data from the message and performs necessary data conversions, such as numeric format conversions or character set conversions.
  3. The Jolt Server makes the appropriate service request to the application service requested by the Jolt client.
  4. Once a service request enters the Oracle Tuxedo system, it is executed in exactly the same manner as requests issued by any other Oracle Tuxedo client.
  5. The results are then returned to the Oracle Jolt Server, which packages the results and any error information into a message that is sent to the Jolt client.
  6. The Jolt client then maps the contents of the message into the various Jolt client interface objects, completing the request.

Jolt Repository

The Jolt Repository is a database where Oracle Tuxedo services are defined, such as name, number, type, parameter size, and permissions. The repository functions as a central database of definitions for Oracle Tuxedo services and permits new and existing Oracle Tuxedo services to be made available to Jolt client applications. An Oracle Tuxedo application can have many services or service definitions, such as ADD_CUSTOMER, GET_ACCOUNTBALANCE, CHANGE_LOCATION, and GET_STATUS. All or only a few of these definitions can be exported to the Jolt Repository. Within the Jolt Repository, the developer or system administrator uses the Jolt Repository Editor to export these services to the Jolt client application.

All Repository services that are exported to one client are exported to all clients. Oracle Tuxedo handles the cases where subsets of services may be needed for one client and not others.

Figure 1-4 illustrates how the Jolt Repository brokers Oracle Tuxedo services to multiple Jolt client applications. (Four Oracle Tuxedo services are shown; however, the WITHDRAW service is not defined in the repository and the TRANSFER service is defined but not exported.)

Figure 1-4 Distributing Oracle Tuxedo Services Through Jolt

Distributing Oracle Tuxedo Services Through Jolt

Jolt Repository Editor

The Jolt Repository Editor is a Java-based GUI administration tool that gives the application administrator access to individual Oracle Tuxedo services. You use the Editor to define, test, and export services to Jolt clients.

Note: The Jolt Repository Editor only controls services for Jolt client applications. You cannot use it to make changes to the Oracle Tuxedo application.

The Jolt Repository Editor lets you extend and distribute Oracle Tuxedo services to Jolt clients without having to modify many lines of code. You can modify parameters for Oracle Tuxedo services, logically group Oracle Tuxedo services into packages, and remove services from created packages. You can also make the services available to browser-based Jolt applets or Jolt applications by exporting the services.

Jolt Internet Relay

The Jolt Internet Relay is a component that routes messages from a Jolt client to the Jolt Server. The Jolt Internet Relay consists of the Jolt Relay (JRLY) and the Jolt Relay Adapter (JRAD). JRLY is a stand-alone software component that routes Jolt messages to the Jolt Relay Adapter. Requiring only minimal configuration to work with Jolt clients, the Jolt Relay eliminates the need for the Oracle Tuxedo system to run on the same machine as the Web server.

The JRAD is an Oracle Tuxedo system server, but does not include any Oracle Tuxedo services. It requires command-line arguments to allow it to work with the JSH and the Oracle Tuxedo system. JRAD receives client requests from JRLY, and forwards the request to the appropriate JSH. Replies from the JSH are forwarded back to the JRAD, which sends the response back to the JRLY. A single Jolt Internet Relay (JRLY/JRAD pair) handles multiple clients concurrently.

 


Creating a Jolt Client to Access Oracle Tuxedo Applications

The main steps for creating and deploying a Jolt client, are described in the following procedure and in the figure Creating a Jolt Application.

  1. Make sure you have created an Oracle Tuxedo system application.
  2. For information about installing Oracle Tuxedo and creating an Oracle Tuxedo application, refer to Installing the Oracle Tuxedo System and Setting Up an Oracle Tuxedo Application.

  3. Install the Jolt system.
  4. Refer to Installing the Oracle Tuxedo System.

  5. Use the Bulk Loader utility to load Tuxedo services into the Jolt Repository Database.
  6. For information on using this utility, see “Bulk Loading Tuxedo Services.”

  7. Configure and define services by using the Jolt Repository Editor.
  8. For information about configuring the Jolt Repository Editor and making Oracle Tuxedo services available to Jolt, see Using the Jolt Repository Editor

  9. Create a client application by using the Jolt Class Library.
  10. The following documentation shows you how to program your client application using the Jolt Class Library:

  11. Run the Jolt-based client applet or application.
  12. Figure 1-5 Creating a Jolt Application

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