One of the functions of the servlet pipeline is to modify a request as it runs through various processing elements. For example, one pipeline element might find the file associated with a given pathInfo, and use that file name to set the pathTranslated property of the request.

The HttpServletRequest interface is immutable—it only provides methods for reading the various properties, but does not provide methods for setting those properties. Oracle ATG Web Commerce provides the class atg.servlet.DynamoHttpServletRequest, which implements HttpServletRequest and provides methods to change request properties, such as setPathInfo and setPathTranslated.

Similarly, the class atg.servlet.DynamoHttpServletResponse, which implements HttpServletResponse, lets you change response properties such as the output stream, and access its values such as statusCode.

The very first element of the servlet pipeline converts an incoming HttpServletRequest/Response pair into a DynamoHttpServletRequest/Response pair. This allows subsequent elements of the servlet pipeline to use the additional functions provided by DynamoHttpServletRequest/Response. These functions are outlined below.