Effective Java

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ITEM 51: DESIGN METHOD SIGNATURES CAREFULLY
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A second technique for shortening long parameter lists is to create 
helper
classes
to hold groups of parameters. Typically these helper classes are static
member classes (Item 24). This technique is recommended if a frequently occur-
ring sequence of parameters is seen to represent some distinct entity. For example,
suppose you are writing a class representing a card game, and you find yourself
constantly passing a sequence of two parameters representing a card’s rank and its
suit. Your API, as well as the internals of your class, would probably benefit if you
added a helper class to represent a card and replaced every occurrence of the
parameter sequence with a single parameter of the helper class.
A third technique that combines aspects of the first two is to adapt the Builder
pattern (Item 2) from object construction to method invocation. If you have a
method with many parameters, especially if some of them are optional, it can be
beneficial to define an object that represents all of the parameters and to allow the
client to make multiple “setter” calls on this object, each of which sets a single
parameter or a small, related group. Once the desired parameters have been set,
the client invokes the object’s “execute” method, which does any final validity
checks on the parameters and performs the actual computation.