1.4 OracleAS Forms Services Components

Oracle Application Server Forms Services is a middle-tier application framework for deploying complex, transactional forms applications to the Internet. Developers can build new applications with Forms Developer and deploy them to the Internet with Forms Services. Developers can also take current applications that were previously deployed in client/server and move them to a three-tier architecture without changing the application code.

OracleAS Forms Services consists of three major components, as shown in Figure 1-2:

The Client, which resides on the client tier
The Forms Listener Servlet, which resides on the middle tier
The Forms Runtime Process, which also resides on the middle tier

Figure 1-2 Three-tier configuration for running a form

A 3 tier configuration running Forms Services.

1.4.1 Forms Listener Servlet

The Forms Listener Servlet acts as a broker between the Java client and the Forms runtime process. It takes connection requests from Java client processes and initiates a Forms runtime process on their behalf.

1.4.2 Forms Runtime Process

The Forms runtime process manages application logic and processing. It maintains a connection to the database on behalf of the Java client. It uses the same forms, menus, and library files that were used for running in client/server mode.

The Forms runtime process plays two roles: when it communicates with the client browser, it acts as a server by managing requests from client browsers and it sends metadata to the client to describe the user interface; when it is communicating with the database server, it acts as a client by querying the database server for requested data.