The ReplyFilter interface is designed to be used by filters that need to process the contents of HTTP reply headers. As in the RequestFilter interface, ReplyFilter also provides a new method called filter(), but in this interface the passed object is a representation of the HTTP reply received from a web server. Any changes made by the filter to the Reply object will be reflected in the resulting HTTP reply sent to the web browser. Figure 4.7 shows the Java code for the ReplyFilter interface.