Corporate Info  |  News  |  Solutions  |  Products  |  Partners  |  Services  |  Events  |  Download  |  How To Buy
	e-docs.beasys.com   |   Site Map   |   Search   |   PDF Files   |   Contact   |   Glossary
WLE Doc Home   |   CORBA Programming & Related Topics   |   Previous   |   Next   |   Contents   |   Index

Using Request-Level Interceptors

This document describes how programmers can implement request-level interceptors in the BEA WebLogic Enterprise (WLE) system. Using request-level interceptors is an advanced programming feature of the WLE system.

This document is intended for programmers who want to create secure, scalable, transaction-based server applications. It assumes you are familiar with CORBA and the C++ and Java programming languages.

This document contains the following topics:

Introduction

Interceptor Architecture

Capabilities and Limitations

Execution Flow

   Client-side Execution

      Client-side Exception Handling

   Target-side Execution

      Target-side Exception Handling

   The exception_occurred Method

   About Short-Circuit Behavior

Using Multiple Request-Level Interceptors

   Multiple Client-side Interceptors

   Multiple Target-side Interceptors

Interceptors and Implementation Languages

Interceptors and Meta-operations

Developing C++ Interceptors

Step 1: Identify the Interfaces of Your WLE Applications

Step 2: Write the Interceptor Implementation Code

   Starting the Implementation File

   Initializing the Interceptor at Run Time

   Obtaining the Interface Name from a Request

   Identifying Operations in the Request

   Implementing the Interceptor's Response Operation

   Reading Parameters out of a Data Input Stream

   Exceptions

Step3: Create the Interceptor Header File

Step 4: Build the Interceptor

Step 5: Test the Interceptor

Developing Java Interceptors

Step 1: Identify the Interfaces of Your WLE Applications

Step 2: Write the Interceptor Implementation Code

   Starting the Implementation File

   Implementing the Interceptor's Constructor

   Obtaining the Interface Name from a Request

   Identifying Operations in the Request

   Implementing the Interceptor's Response Operation

   Reading Data Out of a Data Input Stream

Step 3: Build the Interceptor

Step 4: Test the Interceptor

Notes About Implementing Java Interceptors

Deploying the Interceptor

Registering an Interceptor

Unregistering an Interceptor

Changing the Order in which Interceptors are Called

PersonQuery Sample Application

How the PersonQuery Sample Application Works

   PersonQuery Database

   Client Application Command-line Interface

The OMG IDL for the PersonQuery Sample Application

Building and Running the PersonQuery Sample Application

   Copying the Files for the PersonQuery Sample Application

   Changing the Protection on PersonQuery Application Files

   Setting the Environment Variables

   Building the Client and Server Applications

   Start the PersonQuery Client and Server Applications

   Running the PersonQuery Sample Application

   Stopping the PersonQuery Sample Application

Building and Running the Java RLI Sample Applications

   Copying the Files for the Java PersonQuery Samples

   Changing the Protection on PersonQuery Application Files

   Setting the Environment Variables

   Building the Server Application

   Start the PersonQuery Client and Server Applications

   Running the PersonQuery Sample Application

   Stopping the PersonQuery Sample Application

InterceptorSimp Sample Interceptors

How the PersonQuery Sample Interceptors Work

Registering and Running the PersonQuery Interceptors

   Registering and Running the C++ Interceptors

   Registering and Running the Java Interceptors

Examining the Output of the Interceptors

Unregistering the Interceptors

   Unregistering the C++ Interceptors

   Unregistering the Java Interceptors

InterceptorSec Sample Interceptors

How the PersonQuery Sample Interceptors Work

   How the InterceptorSec Target-side Interceptor Works

   Using the SecurityCurrent Object

   Obtaining the SecurityCurrent Object

   Creating the List of User Attributes

Registering and Running the PersonQuery Interceptors

   Registering and Running the C++ Interceptors

   Registering and Running the Java Interceptors

Examining the Interceptor Output

Unregistering the Interceptors

   Unregistering the C++ Interceptors

   Unregistering the Java Interceptors

InterceptorData Sample Interceptors

InterceptorDataClient Interceptor

InterceptorDataTarget Interceptor

Implementing the InterceptorData Interceptors

Registering and Running the InterceptorData Interceptors

   Registering and Running the C++ Interceptors

   Registering and Running the Java Interceptors

Examining the Interceptor Output

Unregistering the Interceptors

   Unregistering the C++ Interceptors

   Unregistering the Java Interceptors

Request-Level Interceptor API

Interceptor Hierarchy

   Note on Unused Interfaces

Interceptors::Interceptor Interface

   C++ Language Mapping

   Java Language Mapping

RequestLevelInterceptor::
RequestInterceptor Interface

   C++ Language Mapping

   Java Language Mapping

RequestLevelInterceptor::
ClientRequestInterceptor Interface

   C++ Language Mapping

   Java Language Mapping

RequestLevelInterceptor::
TargetRequestInterceptor Interface

   C++ Language Mapping

   Java Language Mapping

CORBA::DataInputStream Interface

   C++ Language Mapping

   Java Language Mapping

Starter C++ Interceptor Files

Starter Implementation Code

Starter Header File Code

Starter Java Implementation File