Wicked Cool Java

All the News Fit to Print: Filtering RSS Feeds with Informa

In the previous section, we polled an RSS feed and wrote some code that automatically updates our copy of the Channel object whenever the feed changes. Our PollerObserverIF implementation added the item to a Channel object. You may think that the observer would be a good candidate for doing some filtering of the feed content, such as deciding whether to add new items to our copy. This could work, but since there can be more than one observer connected to a Poller, it's better to have a separate object do the filtering. By doing this, we won't need to duplicate any filtering functions, ...