The Finder Pattern

In many previous code examples in this blog I've used the “Finder pattern”, that I've elected as one of my best practices (it's standard in all my new APIs and will be retrofitted to the old ones). Before moving on with more examples, I think it's high time I shortly introduced it formally. As the name suggests, it helps whenever you need to provide a search of some type. For instance, in the Hierarchy API the interfaces HView and HItem (name shortened from Hierarchical*** in my previous post) implement a Composite pattern, so a HItem has got children: public interface HView   {       @Nonnull     public Finder findChildren();          @Nonnull     public Builder createChild();          @Nonnull     public Builder findOrCreateChild();   } public interface HItem extends HView   {     @Nonnull     public HView getView();     @Nonnull     public HItem getParent()       throws NotFoundException;   } There are many ways to search for children; for instance, you could search for a specific child with an id, or if you recall that any object in the Hierarchical API is logically bound to another object, you could explicitly search for children with a specific ...

Date: January, 15 2010
Url: http://www.java.net/blog/fabriziogiudici/archive/2010/01/15/finder-pattern

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