java-design-patterns/monostate/index.md

---
layout: pattern
title: MonoState
folder: monostate
permalink: /patterns/monostate/
categories: Creational
tags:
 - Java
 - Difficulty-Beginner
---

**Intent:** Enforces a behaviour like sharing the same state amongst all instances.

![alt text](./etc/monostate.png "MonoState")

**Applicability:** Use the Monostate pattern when

* The same state must be shared across all instances of a class.
* Typically this pattern might be used everywhere a Singleton might be used. Singleton usage however is not transparent, Monostate usage is.
* Monostate has one major advantage over singleton. The subclasses might decorate the shared state as they wish and hence can provide dynamically different behaviour than the base class.

**Typical Use Case:**

* the logging class
* managing a connection to a database
* file manager

**Real world examples:**

Yet to see this.