Understanding the n-Tiered Business Components Architecture

By using the Business Components for Java design-time wizards and editors, you can build business logic tiers by defining the characteristics of components: their attributes, relationships, and business rules. Business Components for Java generates Java source code and XML metadata to implement the behavior you have specified. Because the code inherits from a framework, the Java source files are concise and do not contain large amounts of generated code, so it's easy to see where to add the code that models your business. You can use JDeveloper to add the Java code to enhance or change the behavior, and easily test the application services, independently of the deployment platform.

Business Components for Java then helps you deploy application modules (without modification) to an Oracle 8i JServer environment as Oracle 8i CORBA server objects (physical two-tier), Visibroker CORBA server objects (physical three-tier), OAS EJB session beans (physical three-tier), or Oracle 8i EJB session beans (physical two-tier), or in local mode (physical two-tier).

The following table shows the deployment configurations you can choose. There are three possible physical tiers: the client process, the application server process, and the database process. The database process is always present to manage the application data.

Type of Client

Process Running Client

Type of Business Components Deployment

Process Running Business Components

Number of Physical Tiers

Java Application or Applet

Client Process

Local Mode

Client Process

2

Java Application or Applet

Client Process

VisiBroker CORBA Server Object

Application Server Process

3

Java Application or Applet

Client Process

Oracle8i CORBA Server Object

Database Process

2

Java Application or Applet

Client Process

Oracle8i EJB

Database Process

2

Java Application or Applet

Client Process

EJB in Application Server

Application Server Process

3

JSP, XSQL page, or Servlet

Application Server Process

Local Mode

Application Server Process

2

JSP, XSQL page, or Servlet

Application Server Process

VisiBroker CORBA Server Object

Different Application Server Process

3

JSP, XSQL page, or Servlet

Application Server Process

Oracle8i CORBA Server Object

Database Process

2

JSP, XSQL page, or Servlet

Application Server Process

Oracle8i EJB

Database Process

2

JSP, XSQL page, or Servlet

Application Server Process

EJB in Application Server

Same or Different Application Server Process

2 or 3

Java Stored Procedure

Database Process

Local Mode

Database Process

1