java-design-patterns/servant/README.md

---
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)
Work towards #56: Splitting up the README I did the job and splitted up the readme, hopefully everything was splitted correctly... 2015-08-13 23:54:40 +02:00			`---`
			`layout: pattern`
			`title: Servant`
			`folder: servant`
Work towards #56: Add permalink to every pattern This makes cleaner URLs thanks to jekyll 2015-08-15 18:03:05 +02:00			`permalink: /patterns/servant/`
https://github.com/iluwatar/java-design-patterns-web/issues/8 Update pattern categories and tags 2019-12-13 21:09:28 +02:00			`categories: Behavioral`
fix: Fixed pages showing up in wrong language (#1752) * Fix languages * Missed change for version number * Add language field for presentation * Revert change in README for double buffer Co-authored-by: Jackie Nim <=> 2021-05-19 10:49:05 -06:00			`language: en`
Categorize and tag all patterns #213 2015-12-28 15:52:44 +02:00			`tags:`
https://github.com/iluwatar/java-design-patterns-web/issues/8 Update pattern categories and tags 2019-12-13 21:09:28 +02:00			`- Decoupling`
Work towards #56: Splitting up the README I did the job and splitted up the readme, hopefully everything was splitted correctly... 2015-08-13 23:54:40 +02:00			`---`

Use headings instead of bold text in index.md #238 2016-01-03 21:14:30 +01:00			`## Intent`
			`Servant is used for providing some behavior to a group of classes.`
Work towards #56: Splitting up the README I did the job and splitted up the readme, hopefully everything was splitted correctly... 2015-08-13 23:54:40 +02:00			`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.`

#1113 Link uml-reverse-mapper created class diagrams to readme, where needed 2019-12-07 20:01:13 +02:00			`## Class diagram`
Work towards #56: Splitting up the README I did the job and splitted up the readme, hopefully everything was splitted correctly... 2015-08-13 23:54:40 +02:00			`![alt text](./etc/servant-pattern.png "Servant")`

Use headings instead of bold text in index.md #238 2016-01-03 21:14:30 +01:00			`## Applicability`
			`Use the Servant pattern when`
Work towards #56: Splitting up the README I did the job and splitted up the readme, hopefully everything was splitted correctly... 2015-08-13 23:54:40 +02:00
https://github.com/iluwatar/java-design-patterns-web/issues/8 Update pattern categories and tags 2019-12-13 21:09:28 +02:00			`* When we want some objects to perform a common action and don't want to define this action as a method in every class.`
Work on #226, moved pattern specific references to respective patterns. And removed credits section from Home page. 2016-01-27 12:55:59 +05:30
			`## Credits`
https://github.com/iluwatar/java-design-patterns-web/issues/8 Update pattern categories and tags 2019-12-13 21:09:28 +02:00
Work on #226, moved pattern specific references to respective patterns. And removed credits section from Home page. 2016-01-27 12:55:59 +05:30			`* [Let's Modify the Objects-First Approach into Design-Patterns-First](http://edu.pecinovsky.cz/papers/2006_ITiCSE_Design_Patterns_First.pdf)`