---
layout: pattern
title: Servant
folder: servant
permalink: /patterns/servant/
categories: Behavioral
language: en
tags:
 - Decoupling
---

## Intent
Servant is used for providing some behavior to a group of classes.
Instead of defining that behavior in each class - or when we cannot factor out
this behavior in the common parent class - it is defined once in the Servant.

## Class diagram
![alt text](./etc/servant-pattern.png "Servant")

## Applicability
Use the Servant pattern when

* When we want some objects to perform a common action and don't want to define this action as a method in every class.

## Credits

* [Let's Modify the Objects-First Approach into Design-Patterns-First](http://edu.pecinovsky.cz/papers/2006_ITiCSE_Design_Patterns_First.pdf)