In previous versions of the Web Server, the NSAPI API allowed multiple SAFs to interact in request processing. For example, one SAF could be used to authenticate the client after which a second SAF would generate the content.
In addition to the existing NSAPI interfaces, Sun Java System Web Server introduces NSAPI filters that enable a function to intercept (and potentially modify) the content presented to or generated by another function.
For more information on NSAPI filters in Sun Java System Web Server 6.1, see Chapter 4, Creating Custom Filters.
Two new NSAPI stages, Input and Output, can be used to insert filters in obj.conf. The Input and Output stages are described later in this chapter.