Server Application Functions (SAFs) are used to perform the steps to generate a HTTP request-response. These functions take the request, and server configuration database as input, and return a response to the client as output. The set of functions which are applied are determined by the inputs.
Server application functions have a particular class, where the class corresponds to the request-response step it helps implement. There is an additional class of application function, the initialization function, which is executed upon server startup and performs static data initialization for the various server modules.
Server application functions have a single class and are not informed by the server which class they are being used for. The server keeps an internal table of available functions, and maps these function pointers to unique character strings which identify them. By using this string in the configuration database, a function can be called to carry out one of the above steps.
You can create custom Server Application Functions (SAFs). Creation of SAFs allow you to modify or extend the Sun Java System Web Server's built-in functionality. For example, you can modify the server to handle user authorization in a special way or generate dynamic HTML pages based on information in a database.
For more information about how to create a custom server application function, see Chapter 2, Creating Custom Server Application Functions.