36 lines
1.0 KiB
Markdown
36 lines
1.0 KiB
Markdown
---
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layout: pattern
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title: Memento
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folder: memento
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permalink: /patterns/memento/
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pumlid: DSgn4OCm30NGLM00h3xR2AC3SvRiaxx2-g59zugtDgiz3qdlomNC-10vF-Lik7BF4A_388PIXrBh-J3OwUOlRuT4EssR38XRa7Ay81Lz_o11_RkaQvcf_GS0
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categories: Behavioral
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tags:
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- Java
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- Gang Of Four
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- Difficulty-Intermediate
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---
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## Also known as
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Token
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## Intent
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Without violating encapsulation, capture and externalize an
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object's internal state so that the object can be restored to this state later.
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## Applicability
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Use the Memento pattern when
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* a snapshot of an object's state must be saved so that it can be restored to that state later, and
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* a direct interface to obtaining the state would expose implementation details and break the object's encapsulation
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## Real world examples
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* [java.util.Date](http://docs.oracle.com/javase/8/docs/api/java/util/Date.html)
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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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