Contents

Title and Copyright Information

Send Us Your Comments

Preface

Who Should Read This Guide?

Documentation Accessibility

Prerequisite Reading

Suggested Reading

How This Guide Is Organized

1 How Do Applications Use EJBs?

New Features of EJB 2.0

Local Interface Support

Local Interfaces and Container-Managed Relationships

Local Compared to Remote Access

Home Interface Business Methods

Message-Driven Beans

Enterprise JavaBeans Query Language (EJB QL)

CMP Relationships

Oracle Application Server Object-Relational Mapping

Third Party O-R Mappings - TopLink Integration

CORBA Support - RMI-over-IIOP

Changes in Defaults for Oracle Application Server

Which Type of EJB Should You Use in Your Application?

What is a Session Bean?

Retrieving the Context Using setSessionContext

What is a Stateless Session Bean?

What is a Stateful Session Bean?

What is an Entity Bean?

Entity Beans are Uniquely Identified by a Primary Key

Managing the Persistent Data Within the Entity Bean

Manage Your Persistent Data With Container-Managed Persistence

What is the Difference Between Session and Entity Beans?

When Do You Use a Message-Driven Bean?

What Makes Up An EJB?

Interfaces for Bean Implementation is Based on Bean Type

Parameter Passing Conventions for Your EJBs

How to Handle Returned Parameter Objects

What Container Services Can You Use for EJBs?

2 How to Access EJBs

Steps for Accessing Any EJB

Client Installation of OC4J.JAR

Setting JNDI Properties

No JNDI Properties

JNDI Properties File

JNDI Properties Within The Implementation

JNDI Properties for OC4J Standalone

When Do You Use the Different Initial Context Factory Classes?

An Initial Context Factory Specific to DNS Load Balancing

How to Lookup the EJB Reference

Configuring the EJB Reference Information

Example of How a Client Invokes an EJB

Accessing an EJB in a Remote Server

Accessing an EJB in Another Application

JAAS Support for EJBs

Using the RIMInitialContextFactory Object

Recovering From Deadlock Conditions

Recovering From a NamingException While Accessing a Remote EJB

Recovering From NullPointerException While Accessing a Remote EJB

3 Implementing Session Beans

Developing Session Beans

Implement the Session Bean

Creating the Home Interfaces

Creating the Component Interfaces

Implementing the Bean

Create the Deployment Descriptor

Archive the EJB Application

Prepare the EJB Application for Assembly

Modify the Application.XML File

Create the EAR File

Deploy the Enterprise Application to OC4J

When Does Stateful Session Bean Passivation Occur?

Object Types Enabled for Passivation

Storage of Passivated EJBs

4 CMP Entity Beans

Persistence Fields

Default Mapping of Persistent Fields to the Database

Explicit Mapping of Persistent Fields to the Database

Configuring Lazy Loading on CMP Entity Bean Finder Methods

Conversion of CMP Types to Database Types

Simple Data Types

Serializable Classes

Other Entity Beans or Collections

5 Entity Beans

Entity Bean Overview

Creating Entity Beans

Implement the Entity Bean Home Interface

Implement the Entity Bean Component Interfaces

Implement the Entity Bean Class

How to Define and Use Primary Keys for Your Entity Bean

Defining the Entity Bean Primary Key in a Class

Defining an Auto-Generated Primary Key for Your Entity Bean

Create Data Consistency in Your Entity Bean by Using Persistence

Tie Entity Beans Together Through Container-Managed Relationships

Managing the Entity Bean Lifecycle

Configuring Pool Sizes For Entity Beans

How to Avoid Database Resource Contention

Using Database Isolation Modes to Protect Against Resource Contention

Configuring Entity Bean Concurrency Modes For Handling Resource Contention

Specifying Exclusive Write Access to the Database

Effects of the Combination of the Database Isolation and Bean Concurrency Modes

Differences Between Pessimistic and Optimistic/Serializable

Affects of Concurrency Modes on Clustering

Using Transactions With Entity Beans

Providing Security for Your Entity Beans

6 Entity Relationship Mapping

Transaction Requirements

Defining Entity-To-Entity Relationships

Choosing Cardinality and Direction

One-To-One Relationship Overview

One-To-Many or Many-To-One Relationship Overview

Many-To-Many Relationship Overview

Requirements in Defining Relationships

Define the Get/Set Methods for Each Relationship Field

Set the Relationships in the Bean Implementation

Declare the Relationships in the Deployment Descriptor

Decide Whether to Use the Cascade Delete Option

Mapping Object Relationship Fields to the Database

Default Mapping of Relationship Fields to the Database

Example of a Default Mapping of the One-To-One Relationship

Example of a Default Mapping of One-To-Many and Many-To-Many Relationships

Explicit Mapping of Relationship Fields to the Database

Quick Cookbook for Matching an Existing Database to the Bean Mappings

Steps for Modifying CMR Mapping Elements

Hand-Editing orion-ejb-jar.xml to Map Bean Relationships to Database Tables

One-To-One Relationship Explicit Mapping

Table Mapping For Primary Keys That Use AutoId

Using a Foreign Key with the One-To-Many Relationship

Association Table Explicit Mapping for Relationships Overview

XML Structure for One-to-Many Relationship Mapping

Using an Association Table with a One-to-Many Bidirectional Relationship

Using an Association Table in a One-to-Many Unidirectional Relationship

Using an Association Table in Many-to-Many Relationships

Using a Foreign Key in a Composite Primary Key

How to Override a Foreign Key Database Constraint

Performing Inner or Outer Joins on One-to-One Relationships

Batching SQL statements in your entity beans�

How to map a CMP field and a CMR field to the same row in the database�

Synchronizing Data during Bean Creation�

7 EJB Query Language

EJB QL Overview

Query Methods Overview

Deployment Descriptor Semantics

Finder Method Example

Specifying Finder Methods With EJB QL Syntax

Define the Finder Method in the Home Interface

Define the Finder Method Definition in the Deployment Descriptor

Relationship Finder Example

Specifying Finder Methods With OC4J-Specific Syntax

Add the Finder Method to Home Interface

Add the Query to the OC4J-Specific Deployment Descriptor

Select Method Example

Define the Select Method in the Bean Class

Define the Select Method Definition in the Deployment Descriptor

Oracle EJB QL Type Extensions: Date, Time, Timestamp, and SQRT

8 BMP Entity Beans

Creating BMP Entity Beans

Component and Home Interfaces

BMP Entity Bean Implementation

The ejbCreate Implementation

The ejbFindByPrimaryKey Implementation

Other Finder Methods

The ejbStore Implementation

The ejbLoad Implementation

The ejbPassivate Implementation

The ejbActivate Implementation

The ejbRemove Implementation

Modify XML Deployment Descriptors

Create Database Table and Columns for Entity Data

9 Message-Driven Beans

MDB Implementation Example

EJB Deployment Descriptor (ejb-jar.xml) for the MDB

MDB Using OracleAS JMS

Configure OracleAS JMS in the XML files

JMS Destination Object Configuration

Create the OC4J-Specific Deployment Descriptor to Use OracleAS JMS

Specify the Destination and Connection Factory

Map Any Resource References to JNDI Names

Deploying the MDB

MDB Using Oracle JMS

Install and Configure the JMS Provider

Create User and Assign Privileges

Create JMS Destination Objects

Configure the OC4J XML Files for the JMS Provider

Configure the DataSource

Identify the JNDI Name of the Oracle JMS Data Source

Create the OC4J-Specific Deployment Descriptor to Use Oracle JMS

Specify the Destination and Connection Factory

Map Any Resource References to JNDI Names

Client Access of MDB

Using an Explicit Name for the JNDI Lookup

Accessing OracleAS JMS Destination with Explicit JNDI Names

Accessing Oracle JMS Destination with Explicit JNDI Names

Steps for Sending a Message to an MDB

Using a Logical Name When Client Accesses the MDB

JNDI Naming for OracleAS JMS

JNDI Naming for Oracle JMS

Client Sends JMS Message Using Logical Names

Windows Considerations When Using MDBs

Failover Scenarios When Using a RAC Database

10 Understanding Environment, Deployment, and Packaging

Directory Structure Recommendations for EJB Development

Create the Deployment Descriptor

Archive the EJB Application

Prepare the EJB Application for Assembly

Modify the Application.XML File

Create the EAR File

Deploy the Enterprise Application to OC4J

Out Of Memory Error During Deployment

Sharing Classes

Out of Memory During Execution

ClassCastException

Static Block in an EJB

OC4J Instances Terminating Due To ping Timeout

Configuring Environment References

Environment Variables

Environment References To Other Enterprise JavaBeans

Examples of References to a Local Interface

Accessing EJBs Using Environment References

Examples of References to a Remote Interface

Environment References To Resource Manager Connection Factory References

JDBC DataSource

11 Configuring EJB Application Security

Granting Permissions in Browser

Authenticating and Authorizing EJB Applications

Specifying Users and Groups

Specifying Logical Roles in the EJB Deployment Descriptor

Specifying Unchecked Security for EJB Methods

Specifying the runAs Security Identity

Mapping Logical Roles to Users and Groups

Specifying a Default Role Mapping for Undefined Methods

Specifying Users and Groups by the Client

Specifying Credentials in EJB Clients

Credentials in JNDI Properties

Credentials in the InitialContext

12 EJB Clustering

EJB Clustering Overview

Stateless Session Clustering

Stateful Session Bean Clustering

Combination of HTTP and EJB Clustering

Enabling Clustering For EJBs

Configure the Multicast Address for EJB Clustering

Configure EJB Replication for Stateful Session Beans

VM Termination Replication

End of Call Replication

EJB Clustering Includes JNDI Namespace Replication

Load Balancing Options

Load Balancing Using Static Retrieval

DNS Load Balancing

A XML Reference for ORION-EJB-JAR.XML

OC4J-Specific Deployment Descriptor for EJBs

Enterprise Beans Section

Session Bean Section

Entity Bean Section

Message Driven Bean Section

AC4J Active EJB Section

EJB 1.1 CMP Field Mapping Section

Method Definition

Assembly Descriptor Section

Element Description

B Third Party Licenses

Apache HTTP Server

Index