The Java EE 6 Tutorial, Volume I

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:

The counter’s access methods are synchronized to prevent incompatible operations by servlets that are running concurrently. A filter retrieves the counter object using the context’s getAttribute method. The incremented value of the counter is recorded in the log.