The J2EE™ Tutorial Second Edition

Accessing the Web Context

The context in which Web components execute is an object that implements the ServletContext interface. You retrieve the Web context using the getServletContext method. The Web context provides methods for accessing:

• Initialization parameters

• Resources associated with the Web context

• Object-valued attributes

• Logging capabilities

The Web context is used by the Duke's Bookstore filters filters.HitCounterFilter and OrderFilter, which are discussed in Filtering Requests and Responses (page 454). Each filter stores a counter as a context attribute. Recall from Controlling Concurrent Access to Shared Resources (page 445>) that the counter's access methods are synchronized to prevent incompatible operations by servlets that are ...