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Merge pull request #490 from iluwatar/DocumentUsages

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#211 Document GoF usages from Java API
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Ilkka Seppälä
2016-09-03 14:14:13 +03:00
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state/README.md
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@ -26,6 +26,11 @@ Use the State pattern in either of the following cases
* an object's behavior depends on its state, and it must change its behavior at run-time depending on that state
* operations have large, multipart conditional statements that depend on the object's state. This state is usually represented by one or more enumerated constants. Often, several operations will contain this same conditional structure. The State pattern puts each branch of the conditional in a separate class. This lets you treat the object's state as an object in its own right that can vary independently from other objects.
## Real world examples
* [javax.faces.lifecycle.Lifecycle#execute()](http://docs.oracle.com/javaee/7/api/javax/faces/lifecycle/Lifecycle.html#execute-javax.faces.context.FacesContext-) controlled by [FacesServlet](http://docs.oracle.com/javaee/7/api/javax/faces/webapp/FacesServlet.html), the behavior is dependent on current phase of lifecycle.
* [JDiameter - Diameter State Machine](https://github.com/npathai/jdiameter/blob/master/core/jdiameter/api/src/main/java/org/jdiameter/api/app/State.java)
## Credits
* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)