Intent

A fluent interface provides an easy-readable, flowing interface, that often mimics a domain specific language. Using this pattern results in code that can be read nearly as human language.

Implementation

A fluent interface can be implemented using any of

Method Chaining - calling a method returns some object on which further methods can be called.
Static Factory Methods and Imports
Named parameters - can be simulated in Java using static factory methods.

Applicability

Use the Fluent Interface pattern when

you provide an API that would benefit from a DSL-like usage
you have objects that are difficult to configure or use

Real world examples

Credits