Merge branch 'master' into master
This commit is contained in:
Sanket Panhale
GitHub
@ -3,7 +3,6 @@ layout: pattern
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title: Abstract Factory
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folder: abstract-factory
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permalink: /patterns/abstract-factory/
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pumlid: PSZB3OD034NHLa81Czwd6sCC39gVxEUWT1_ssLmTtQLqgR5fM7sTmFGtaV6TZu8prd0r6HtQaMKqAZLk1XjT_E6qgPUZfyc0MdTgx0-8LuUn8ErFXdr98NypXxKyezKV
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categories: Creational
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tags:
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- Java
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@ -120,6 +119,45 @@ king.getDescription(); // Output: This is the Elven king!
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army.getDescription(); // Output: This is the Elven Army!
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```
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Now, we can design a factory for our different kingdom factories. In this example, we created FactoryMaker, responsible for returning an instance of either ElfKingdomFactory or OrcKingdomFactory.
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The client can use FactoryMaker to create the desired concrete factory which, in turn, will produce different concrete objects (Army, King, Castle).
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In this example, we also used an enum to parameterize which type of kingdom factory the client will ask for.
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```
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public static class FactoryMaker {
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public enum KingdomType {
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ELF, ORC
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}
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public static KingdomFactory makeFactory(KingdomType type) {
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switch (type) {
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case ELF:
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return new ElfKingdomFactory();
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case ORC:
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return new OrcKingdomFactory();
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default:
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throw new IllegalArgumentException("KingdomType not supported.");
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}
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}
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}
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public static void main(String[] args) {
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App app = new App();
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LOGGER.info("Elf Kingdom");
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app.createKingdom(FactoryMaker.makeFactory(KingdomType.ELF));
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LOGGER.info(app.getArmy().getDescription());
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LOGGER.info(app.getCastle().getDescription());
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LOGGER.info(app.getKing().getDescription());
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LOGGER.info("Orc Kingdom");
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app.createKingdom(FactoryMaker.makeFactory(KingdomType.ORC));
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-- similar use of the orc factory
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}
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```
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## Applicability
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Use the Abstract Factory pattern when
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@ -141,9 +179,15 @@ Use the Abstract Factory pattern when
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* Dependency injection in java hides the service class dependencies that can lead to runtime errors that would have been caught at compile time.
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## Tutorial
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* [Abstract Factory Pattern Tutorial](https://www.journaldev.com/1418/abstract-factory-design-pattern-in-java)
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## Presentations
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* [Abstract Factory Pattern](etc/presentation.html)
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## Real world examples
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* [javax.xml.parsers.DocumentBuilderFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/parsers/DocumentBuilderFactory.html)
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BIN
abstract-factory/etc/diagram1.png
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abstract-factory/etc/presentation.html
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abstract-factory/etc/presentation.html
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@ -0,0 +1,190 @@
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<!--
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The MIT License
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Copyright (c) 2017 Rodolfo Forte
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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|
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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THE SOFTWARE.
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-->
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<!DOCTYPE html>
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<html>
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<head>
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<title>Design Patterns - Abstract Factory Presentation</title>
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<meta charset="utf-8">
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<style>
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@import url(https://fonts.googleapis.com/css?family=Yanone+Kaffeesatz);
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@import url(https://fonts.googleapis.com/css?family=Droid+Serif:400,700,400italic);
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@import url(https://fonts.googleapis.com/css?family=Ubuntu+Mono:400,700,400italic);
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body { font-family: 'Droid Serif'; }
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h1, h2, h3 {
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font-family: 'Yanone Kaffeesatz';
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font-weight: normal;
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}
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.remark-code, .remark-inline-code { font-family: 'Ubuntu Mono'; }
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blockquote {
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border-left: 0.3em solid rgba(0,0,0,0.5);
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padding: 0 15px;
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font-style: italic;
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}
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img {
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max-width:100%;
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}
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</style>
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</head>
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<body>
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<textarea id="source">
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class: center, middle
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# Abstract Factory
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---
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# Also known as
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* Kit
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---
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# Intent
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* Provide an interface for creating families of related or dependent objects without specifying their concrete classes
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---
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# Explanation
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* [Wikipedia](https://en.wikipedia.org/wiki/Abstract_factory_pattern) says:
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> "The abstract factory pattern provides a way to encapsulate a group of individual factories that have a common theme without specifying their concrete classes"
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<br />
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* In plain words:
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* A factory that groups individual but related/dependent factories together without specifying their concrete classes;
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* A factory of factories;
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---
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# Example
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* In a factory that creates kingdoms, we need objects with common theme:
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* Elven kingdom needs an Elven king, Elven castle and Elven army;
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* Orcish kingdom needs an Orcish king, Orcish castle and Orcish army;
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<br />
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* There is a dependency between the objects in the kingdom;
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---
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# Diagram
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* Based on the kingdom example, the diagram below showcases the different concrete factories and their concrete products:
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.center[]
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---
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# Diagram
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* The class diagram below showcases the factory of factories;
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* At runtime, we can define which Kingdom type is needed and pass it as a parameter to define which concrete KingdomFactory to instantiate;
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* The concrete factory returned will then be able to produce the related objects of the specified type;
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.center[]
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---
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# Applicability
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Use the Abstract Factory pattern when:
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* A system should be independent of how its products are created, composed and represented;
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* A system should be configured with one of multiple families of products;
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* A family of related product objects is designed to be used together, and you need to enforce this constraint;
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* You want to provide a class library of products, and you want to reveal just their interfaces, not their implementations;
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---
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# Applicability
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Use the Abstract Factory pattern when:
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* The lifetime of the dependency is conceptually shorter than the lifetime of the consumer;
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* You need a run-time value to construct a particular dependency;
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* You want to decide which product to call from a family at runtime;
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* You need to supply one or more parameters only known at run-time before you can resolve a dependency;
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---
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#Use Cases
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* Selecting to call the appropriate implementation of FileSystemAcmeService or DatabaseAcmeService or NetworkAcmeService at runtime;
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* Unit test case writing becomes much easier;
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---
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# Consequences
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* Dependency injection in java hides the service class dependencies that can lead to runtime errors that would have been caught at compile time
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---
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# Real world examples
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[javax.xml.parsers.DocumentBuilderFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/parsers/DocumentBuilderFactory.html)
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[javax.xml.transform.TransformerFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/transform/TransformerFactory.html#newInstance--)
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[javax.xml.xpath.XPathFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/xpath/XPathFactory.html#newInstance--)
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---
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# Credits
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* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)
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---
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# Tutorials
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* Source code http://java-design-patterns.com/patterns/abstract-factory/
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</textarea>
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<script src="https://gnab.github.io/remark/downloads/remark-latest.min.js">
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</script>
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<script>
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var slideshow = remark.create();
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</script>
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</body>
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</html>
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@ -29,13 +29,18 @@
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<parent>
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<groupId>com.iluwatar</groupId>
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<artifactId>java-design-patterns</artifactId>
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<version>1.17.0-SNAPSHOT</version>
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<version>1.19.0-SNAPSHOT</version>
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</parent>
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<artifactId>abstract-factory</artifactId>
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<dependencies>
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<dependency>
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<groupId>junit</groupId>
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<artifactId>junit</artifactId>
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<groupId>org.junit.jupiter</groupId>
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<artifactId>junit-jupiter-api</artifactId>
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<scope>test</scope>
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</dependency>
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<dependency>
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<groupId>org.junit.jupiter</groupId>
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<artifactId>junit-jupiter-engine</artifactId>
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<scope>test</scope>
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</dependency>
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</dependencies>
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@ -25,6 +25,8 @@ package com.iluwatar.abstractfactory;
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import org.slf4j.Logger;
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import org.slf4j.LoggerFactory;
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import com.iluwatar.abstractfactory.App.FactoryMaker.KingdomType;
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/**
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*
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* The Abstract Factory pattern provides a way to encapsulate a group of individual factories that have a common theme
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@ -56,7 +58,7 @@ public class App {
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setCastle(factory.createCastle());
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setArmy(factory.createArmy());
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}
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King getKing(final KingdomFactory factory) {
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return factory.createKing();
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}
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@ -92,9 +94,36 @@ public class App {
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private void setArmy(final Army army) {
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this.army = army;
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}
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/**
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* Program entry point
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* The factory of kingdom factories.
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*/
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public static class FactoryMaker {
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/**
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* Enumeration for the different types of Kingdoms.
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*/
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public enum KingdomType {
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ELF, ORC
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}
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/**
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* The factory method to create KingdomFactory concrete objects.
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*/
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public static KingdomFactory makeFactory(KingdomType type) {
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switch (type) {
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case ELF:
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return new ElfKingdomFactory();
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case ORC:
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return new OrcKingdomFactory();
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default:
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throw new IllegalArgumentException("KingdomType not supported.");
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}
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}
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}
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/**
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* Program entry point.
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*
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* @param args
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* command line args
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@ -104,17 +133,15 @@ public class App {
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App app = new App();
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LOGGER.info("Elf Kingdom");
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app.createKingdom(new ElfKingdomFactory());
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app.createKingdom(FactoryMaker.makeFactory(KingdomType.ELF));
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LOGGER.info(app.getArmy().getDescription());
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LOGGER.info(app.getCastle().getDescription());
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LOGGER.info(app.getKing().getDescription());
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LOGGER.info("Orc Kingdom");
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app.createKingdom(new OrcKingdomFactory());
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app.createKingdom(FactoryMaker.makeFactory(KingdomType.ORC));
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LOGGER.info(app.getArmy().getDescription());
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LOGGER.info(app.getCastle().getDescription());
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LOGGER.info(app.getKing().getDescription());
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}
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}
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}
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@ -22,11 +22,14 @@
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*/
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package com.iluwatar.abstractfactory;
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import static org.junit.Assert.assertEquals;
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import static org.junit.Assert.assertTrue;
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import static org.junit.jupiter.api.Assertions.assertEquals;
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import static org.junit.jupiter.api.Assertions.assertTrue;
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import org.junit.Before;
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import org.junit.Test;
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import com.iluwatar.abstractfactory.App.FactoryMaker;
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import com.iluwatar.abstractfactory.App.FactoryMaker.KingdomType;
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import org.junit.jupiter.api.BeforeEach;
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import org.junit.jupiter.api.Test;
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/**
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* Test for abstract factory
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@ -37,10 +40,10 @@ public class AbstractFactoryTest {
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private KingdomFactory elfFactory;
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private KingdomFactory orcFactory;
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@Before
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@BeforeEach
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public void setUp() {
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elfFactory = new ElfKingdomFactory();
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orcFactory = new OrcKingdomFactory();
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elfFactory = FactoryMaker.makeFactory(KingdomType.ELF);
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orcFactory = FactoryMaker.makeFactory(KingdomType.ORC);
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}
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@Test
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@ -22,7 +22,7 @@
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*/
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package com.iluwatar.abstractfactory;
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import org.junit.Test;
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import org.junit.jupiter.api.Test;
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import java.io.IOException;
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|
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